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AMA's Bill Dart on Thumper pipes; must read

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Posted by: mtngoat---------------------

This may not be what we (or others) want to hear, but we need to listen up.

NOISE RESURFACES AS A MAJOR ISSUE

By Bill Dart, AMA District 36 Legislative Officer

Noise has always been one of the biggest reasons people don't like dirt bikes. I am not talking about just environmental groups that don't like OHV recreation on general principles and philosophy, either. We can deal with almost every issue they raise. We can deal with water quality, air quality, erosion, wildlife issue, botanical issues, archaeological issues, and user conflict issues. Often, all of these are just surrogate issues for the real, underlying reason; nobody likes noisy dirt bikes.

I don't think we will ever be able to satisfy environmental extremists, but we need to quit making the general public mad at us over noise. Susie Soccer Mom doesn't like noisy dirt bikes. Joe Six Pack doesn't like noisy dirt bikes. Virtually every single elected official, appointed regulator or public land manager, doesn't like noisy dirt bikes. I don't like noisy dirt bikes.

Noise has always been a major issue, but until a couple of years ago, the trend was towards much more quiet dirt bikes. Water cooling, tighter engine tolerances, better induction systems, and better mufflers had brought the sound level of most dirt bikes down into the mid to low 90 db range by the early 90's. Most of the older, louder air cooled bikes have gone to that big riding area in the sky, or are rusting out behind the shed under a tarp, and noise complaints had dropped off as a major issue.

So what happened? New four-strokes are what happened, especially the popular Yamaha 400/426 series. While right on the margin of legality, they are still too noisy right out of the crate. But the problem really gets bad when an aftermarket exhaust system is installed, which it seems about 90% of these bikes have today. Dirt Rider magazine did testing for power and sound levels on all of the popular exhaust system available for the Yamaha 400/426 series, as well as the new Suzuki DRZ400. According to their testing, the Yamaha measured 100 db stock, barely within the 99db, plus or minus 2 db, mandated by California law. But none of the aftermarket pipes tested came in below 102db, and most were between 104 and 106 db. This means that NONE of the aftermarket pipes for the 400/426 are legal to use anywhere on public lands in California, not even for racing.

"But, those are racing systems," is the response from the aftermarket companies. Baloney! AMA rules have a maximum noise level of 99db. None of them are legal for AMA amateur racing. And what about other private tracks that aren't AMA? Well, many of those tracks have been shut down. Why? Because people hate noisy dirt bikes! I asked most of these companies if they had ever tried to get a permit for a new track, as I have several times. I bet you can guess the single biggest reason why many tracks are never granted permits. If you guessed noise, you are starting to get the drift on the noise issue. Even the thin thread of credibility about the YZ400/426 being a race bike and the aftermarket pipes were designed for closed course racing, went out the window when we read a similar test on all of the pipes for the Suzuki DRZ400.

Unlike the Yamaha, the Suzuki doesn't pretend to be a race bike. It is a recreational trail bike that would cost more to make truly race worthy than a couple of Yamahas. It makes very good useable power, but less than the Yamaha. What really impressed everybody who has heard one is just how quiet it is, yet it still has outstanding performance. Dirt Rider tested it at 90 db with the stock pipe, which is very quiet, and it still puts out over 40 horsepower. For comparison, the latest 426 Yamaha has about 45 horsepower and the Honda XR 400 puts out just a little over 30 horsepower.

Well, the DRZ400 noise got just about as bad as the Yamaha, once the stock pipe was replaced. Not a single one is AMA legal, according to the Dirt Rider data. Only one is barely California legal, the Stroker spark arrestor model, at 100 db. All the rest are between 102 and 104.

But, what about all that extra power that comes with the noise, isn't that reason enough? Well, in the case of the Yamaha, none of the pipes even matched the stock pipe's midrange, where most riding is done. Most of them made less than one horsepower more than the stock pipe. A couple made less than two horsepower over stock, one at extremely low RPM, and one at nearly 11,000 RPM. In fact, some of them were even lower in power than stock at almost every RPM. A one horsepower gain at the ends of the powerband, while losing several horsepower in the most used midrange, does not amount to a performance increase.

What about that choked down Suzuki? It must have made major horsepower leaps with an aftermarket system, right? Sorry, Charlie! Only modest gains were made, a horsepower or two. Barely noticeable. But, boy, EVERYBODY noticed the difference in sound levels.

Expect Heavy Noise Law Enforcement in 2002
Where do we go from here? Well, the OHV Division just convened a committee to address the noise issue, of which I am a member. They have been charged with developing a recommendation for a new sound limit law. The Motorcycle Industry Council has already recommended that level be lowered to 96db, with no plus or minus variation, as a level the industry can comply with. This is likely to be the highest the new law will allow.

"But so what?", you might say. Nobody is enforcing sound limits anyway. Well, things are changing in this field as well. Noise enforcement will be a priority next year. The OHV Division will be providing all of the test equipment needed to every agency that requests it, and the MIC has updated their technical test data manual, so that all models can be properly and legally tested. Additionally, with law enforcement grants exploding this year, and the new state emphasis on noise enforcement, you can expect rigorous field enforcement this year all over the state.

Due to the new emphasis on law enforcement, and the enhanced communication between all of the various law enforcement agencies dealing with OHV's, the sound level of the aftermarket four-stroke exhaust systems has been recently circulated throughout that community, and anyone with an aftermarket exhaust on a four-stroke will be automatically suspect, and the officer will have probable cause to do a stop and sound test.

If you have been considering buying an aftermarket exhaust for your four-stroke, you might want to reconsider, especially if you can't get reliable data that it meets current laws. If you'll want to use it for the long term, you'll want to look for pipes at or below 96 db, since it is almost a certainty that the noise limit will be lowered. The only debate will be about just how much it will be lowered. If you already have an aftermarket system that is over the legal or AMA limit, I would urge you to demand a refund, since it is not even legal for AMA-sanctioned, amateur closed-course racing.

More important than being technically legal, if we really love to ride and want to protect our sport, we need to do everything we can to reduce noise well below the legal limits. We need to make friends, not enemies, and all we really get from noise are more enemies -- except for a few companies making significant money selling socially irresponsible products for big bucks. Can anybody give me a believable reason why a four-stroke exhaust system, with a simple head pipe and a simple can muffler, costs twice as much or more, than a two-stroke system?

Let's bring back the programs that brought the noise levels down before. TEAM STEALTH. Less Sound = More Ground. We need to reward companies that make quiet yet more powerful and lighter pipes. We need to make quiet COOL, instead of nerdy, like the undertone in the enthusiast press does today. We need to harass our fellow riders using obnoxious pipes, until they do something about it. Because, if we don't, all we are doing is digging our own grave.


Posted by: Milquetoast---------------------

Yes! Bring back TEAM STEALTH! Nobody I have ever seen ride in person needs that extra one or two horsepower. And don't forget that this problem exists on street bikes too (are you listening Harley riders?).


Posted by: stroker---------------------

Very well written, you are exactly right. Even up here in Canada, the number one reason wht we are losing riding areas is NOISE.... we have to smarten up or the only riding we will be doing is on bicycles.

Take resposibility for yourself, make sure that your bike is quiet.

Take responsibility for your favourite riding areas, make sure your riding buddies bikes are quiet, even talk to the guys you don't know, explain the vital importance of this.

Force the pipe manfacturers to start producing quiet powerfull pipes, How? quit paying through the nose to buy overpriced crap that usually dosen't work ($300 to $750 for 1 or 2 hp and double the noise, we should be embarrassed to admit we got suckered like that) STOP BUYING LOUD PIPES!
Then and only then will the pipe companies spend the $$ to design something that actually works, and we start getting some real value for our money.

If we don't fix it ourselves, the government WILL step in and either eliminate us, or make us remember the "good old days" when we had lots of riding areas and had 400cc bikes that made 45hp, if they set the noise level at 89db, current muffler technology will make for XR400 kind of power, as good as it gets.


Posted by: marcusgunby---------------------

I can see the future- no 2 stokes after 2006, 2007 all bikes banned due to noise, in the UK the AMCA has ruled all 4 strokes have to use std exhaust with no tampering, since 1988 we have had sound testers at local meetings.I hate noisy 4 strokes BTW.


Posted by: yz250-effer---------------------

That is why I have kept the stock silencer on my 250F. Stock, I don't feel it is any louder than any 2 stroke? But I could be wrong. The noise of a 4 stroke carrys further, too, and that certainly does not help.


Posted by: klymr---------------------

very well said Mtn Goat! I hope others will listen and realize this noise issue is no joke, but a reality that is going to cause OHV'rs to lose ground.

Wake up everyone and dont get suckered by the magazines selling the must have loud pipes! Hmmm, who's advertisements are in the mags? is there a connection there do you think?

klymr


Posted by: vince321---------------------

This whole issue gives me a rash. Even though I realize that stricter laws will probably force people to run quieter pipes. I personaly like a louder pipe and think it makes a bike sound better. It's amazing to me that everytime a few people complain, new laws have to be made.

When it comes to dirt bikes, there is simply a double standard. Almost all Harleys make an unbelievable amount of noise. These exhausts are intentionaly put on to increase and change the sound over a stock muffler. However, I haven't heard of any new laws being made to decrease their noise levels. Of course, if a dirt bike is made to run louder than some people find acceptable, new rules have to be made.

On a separate note, with the push to outlaw two strokes, has anyone considered snowmobiles? There are literally hundereds of two stoke snowmobiles riding around the northern United States. I haven't heard any complanits about them. These things make a considerable amount of noise and blow all kinds of smoke.

Anyway, I could probably vent for a few more paragrahps but I won't. It'll have to be enought to realize that if new laws state 96db, than that's what I'll have to run.


Posted by: 380EXCman---------------------

Im going to really sound like a jerk now but its just the way I see it.

I also feel that people should be more responsible and try to make their bikes as quiet as they can. I am a big proponet of silencer packing (my back ground is in high temperature insulation) and feel that most people do not repack it often enough (wich equals less power and more noise). I also believe that alot of people buy a pipe for its alleged power increases, or they just like the looks or sound. How is it that KTM and the other Euro mfg's are the only ones that can make a pipe that is a good comprimise of power, weight and noise. You Jap bike fans really need to cry more about what you get for your buck just like we all should complain to the pipe makers that they are making nothing more than crap. You can bronse a turd and make it look pretty but its still a turd!

But what really pisses me off is all the people that want to meet our enemies 1/2 way. No matter what we do there will always be someone that does not like what we do period. And if we continue to meet them 1/2 way we will negoitiate ourselves out of exsitence. While I do feel this topic has "some" merit just like some of the enviromental impact isssues have some. I will not waiver. I will take responsibility for myself and do what "I" think is right but when it comes down to the wire I will ride past "Trail Closed" signs and ride right around Johny Ranger and his DB meter. Am I jerk? Maybe. Will I make it worse for the rest? Maybe. But I really dont care. Where are the comprimises at on the other side of the argument? They dont exsist. Its like the comedian said "I saw a handi-cap person park in one of our spots the other day, I kicked his arse."

Its no different for me with hunting. If it is ever outlawed I will become an outlaw and a poacher.


Posted by: bwalker---------------------

Vince, Have you heard a snowmobile lately. They are very quiet, even with aftermarket pipes. The snowmobile industry realised that noise was a problem and addressed it. I wish the motorcycle industry would do the same. What good are loud pipes with no place to ride? Two gus with 426's and pc exhausts got a private track shutdown that I rode on. Its pretty stupid imo givin the miniscule gain over the fcatory piece which is loud as is. bTW IMO The exhaust note of a foustroke is more noticable at long distances than a two stroke even if both have simular DB rateings. It must be a tone issue.


Posted by: scar tissue---------------------

mtngoat, your post stated that none of the aftermarket pipes tested were good for quiet riding.

What about the FMF quiet pipe, or the White Bros version. Were those tested? As you know I'm getting a Canadian WR250f and the 2 draw backs are the wieght of the pipe and how restrictive the Canadian pipe is. I was eithr going to get an aftermarket pipe imediatly or I was actually thinking of finding a stock yz250f pipe to run an adding a spark arrester. Any other ideas?


Posted by: kciH---------------------

I have a 01 YZ426, and it is a good deal louder than a 250 2-stroke with aftermarket exhaust. At a local riding area I was drag racing 4 250's at once and my riding buddies said they couldn't even hear the two stroke bikes. This is with the factory exhaust on the four stroke. If you think the 426 is loud, you should hear a Raptor with ANY aftermarket exhaust on it.

I am considering a Big Gun exhaust with the quiet core silencer. They claim no loss of power from stock at 94dB or less! I hope these are more than just "claims". If anybody knows how these pipes are performing, please respond...good,bad, or slow.


Posted by: Milquetoast---------------------

Quote:
When it comes to dirt bikes, there is simply a double standard. Almost all Harleys make an unbelievable amount of noise. These exhausts are intentionaly put on to increase and change the sound over a stock muffler. However, I haven't heard of any new laws being made to decrease their noise levels. [/B]


You haven't? Read the AMA magazine and you'll hear of alot of them.


Posted by: ktmmudd---------------------

I agree with 380EXCman, I'll compromise with the greens when they compromise with us! :mad:


Posted by: mtngoat---------------------

Scar,
the White Bros E-Series can attenuate sound by removing disks (some effect) and/or by adding a quiet core insert (more, I expect). I'd bet, between the two options, sound level can be brought in range. Most of my riding buddies went with the E-Series, so they'll probably buy the quiet core. I have an FMF megamax on one of my bikes and I believe there is a quiet core option for it too. Not sure about the performax series. I'm considering the purchase of a db meter to know where we stand and guard against overzealous rangers and their new db toys this summer.

Appreciate the positive feedback guys, but just to be clear, I didn't write the article. Bill Dart, the author has always struck me as a "voice of reason" with tough issues. I agree with Bill, but I'm not wholly innocent (got some pipe changes to do this summer).

However, I live by a credo that my innocence can't be established by another's guilt. The harley riders, snowmobiles, whatever are getting hit or will be hit. In any event their guilt will not dismiss my defiance or inaction.


Posted by: vince321---------------------

bwalker, yes I've heard snowmobiles lately. As a matter of fact, I'll be riding one later this month in the Upper Peninsula of Michigan with thirteen other people. One snomobile by it's self isn't that loud. However, when you get a pack of them together, they make a considerable amount of racket.

Anyway, if we all had motorcycles that were as quiet as snowmobiles, they would still be too loud. The people who want to impose their view of whats right for society (Including loud aftermarket pipes) don't like dirtbikes and won't be happy until we can't ride them, period.

BTW - My neighbor has a Harley that's kind of loud, I wan't it outlawed.

The other day, while walking through the woods, someone fired a rifle. It scared my dog. I want rifles outlawed.

A couple of months ago, my wife and I were having dinner in Kemah, a loud boat went by the marina and interrupted our conversation. These things need to be outlawed.

Last year, a friend of mine was killed riding his Truimph sport bike. Those things are way to fast. We gotta find and agency to outlaw'em. Not to mention, his pipe was kinda loud.

The other day, while at a stop light, a dude in a pick-up truck pulled up along side me. It was all jacked up with huge tires. Blocked my view of the intersection. There needs to be a law to lower those things.

On Saturday, while riding at the local MX park, some guy had a White Bros. exhaust that was extremely loud. We gotta outlaw them too........................

I am intentionally being facetious to illustrate a point. There are many things that can bother people everyday. However, creating new laws for everyone with an agenda is beyond me.


Posted by: Milquetoast---------------------

Then you, Vince, are part of the problem.


Posted by: Bobt250---------------------

The guys that get suckered into buying aftermarket pipes on promises of horsepower gains always cracked me up. I'm highly amused by the Dyno results listed above. I've always thought those types of people "thought" their bike was faster just because it was making more noise.

Then again, there are the people with the "harley mentality". They want to be "seen". Hey look at me......ain't I cool? I'll make sure you can't miss me...what with all that noise how can you miss me?

I also believe that most people will never give up on ending our fun and will never be satisfied until we are standing in line at the golf course for a tee time. Hey, maybe that'll get 'em. Make those lines longer and maybe they'll want us to go back out into the woods 'eh?

BUT SERIOUSLY! THEY CAN'T MESS WITH US IF THEY DON'T EVEN KNOW WE ARE THERE !!

Loud four strokes are obnoxious.

STEALTH !!


Posted by: Neil Wig---------------------

We must make some effort to make dirt bikes less offensive to those that vote. They may be whiners, but that's the way it goes.

BWalker - with regard to snowmobiles with aftermarket pipes, I disagree. A co-worker bought a new thundercat. With the stock pipe and silencer it was nice and quite. He put stinger pipes and an aftermarket silencer on it, and even he says he needs ear plugs. I think that level of noise needs to be adressed.


Posted by: needsprayer---------------------

"when it comes down to the wire I will ride past "Trail Closed" signs and ride right around Johny Ranger and his DB meter."


Inviting the law to chase you is not a great strategy. You could lose your bike and freedom over a little baffling. There are bigger battles to fight, like being able to use the land.


Posted by: bwalker---------------------

Quote:
A co-worker bought a new thundercat. With the stock pipe and silencer it was nice and quite. He put stinger pipes and an aftermarket silencer on it, and even he says he needs ear plugs. I think that level of noise needs to be adressed.

I was talking about new sleds and the aftermarket pipes that are available from componies like PSI and SLP. Both make quiet sytems. All aftermarket pipes for sleds two years ago where very loud till the industry got together and semanded quiet pipes.

Vince, A whole fleet of sleds is less offensive than one 426. BTW I lived in the UP for five years and have riden sleds my whole life so I know what i am talking about.


Posted by: 380EXCman---------------------

Quote:
Inviting the law to chase you is not a great strategy. You could lose your bike and freedom over a little baffling. There are bigger battles to fight, like being able to use the land.
I agree with that, but a day will come when we all will have to make that choice. We cannot continue to give up our freedoms and pleasures, because a group or person find them "offensive". It will not end, and in my opinion the people who cave to these attacks are cowardly and are simply buying time.

And my statement above is applicable to many many situations we have in this country.


Posted by: Jay-R---------------------

Has anyone noticed all of the people trying to get golf outlawed. That is because hitting a ball and riding a golf cart are both quiet. If we don't agree to quieten our motorcycles how are we ever going to succeed in making all golf courses into motocross tracks?

That is our goal isn't it?


Posted by: needsprayer---------------------

I agree that we must defend and fight for our freedoms.


"It will not end, and in my opinion the people who cave to these attacks are cowardly and are simply buying time. "

The following is my opinion and is not directed at any one person.


One of the objectives of war is to eliminate the enemies' ability to wage war. The wackos scream about environmental damage. If Off Road Vehicle users showed that they protected the environment and the use of that environment through the exercise of good judgement, i.e. avoidng excessive noise, not exhibiting rude behavoir and contributing to the maintenance of the public facility then that virtue becomes our weapon. At the same time it takes a weapon away from the enemy.

This virtue is not caving in. It is an inner strength that will be recognized and admired.


Posted by: bwalker---------------------

Needsprayer,Very well said. Maybe lose a battle but win the war.


Posted by: mechantloup---------------------

If we ride quiet bikes ( ever done a "stealth" pass? ,were the rider in front with a noisy pipe didn't heard you coming swweet!! ) and encourage friends to do the same,we will have made good progress against eco-sniveling ...i drag raced a friend of mine a dozen time to prove his 800$ pipe was no faster and it wasn't, it made is bike harder to launch that's all... Whatever he gained in power he lost in usability.. Dirt riding is not about who has the most power but who is able to use what's avaible to best advantage .

please forgive my bad english


Posted by: MXer60---------------------

I have to agree with vince. Just because someone doesn't like something it automatically should be outlawed. WHO are these people to determine what is right for me? I actually like the sound of a nice loud highly tuned dirtbike. Has anyone ever been to a NASCAR race or a drag strip?? How about a mud bog? The vehichles used in those activities are way way louder than that of my crf. Granted you don't see these vehicles driving around the woods, but they are loud are they not? Also on the Harley comment, I know for a fact they are louder than my crf. An old coworker of mine just bought a brand new Fatboy, and we were outside of my house. We both started our bikes and reved them up to see which was louder. You couldn't even here my crf to that thing! And her rides it all around town and everything else. I think others are correct when the say "people just don't like dirtbikes". Do any of you live close to railroad tracks? I have for the past 15 years and they are a great deal louder than my bike, but noone says anything about those things. I again agree with vince when he makes the comments about his "outlaw list" because in all honesty it is true. Unfortunately we are few and they are many, but us few have to stand up and draw the line somewhere otherwise we will eventually be forced to race electric scooters around the parking lot of the local walmart. The decision is your's to make.


Posted by: 380EXCman---------------------

Quote:
Unfortunately we are few and they are many
I dont think that is the case. I think they are more active, educated, funded and militent.

We should be the same way. But trying to sell the average person on the street that a dirt bike,horse,4-wheeler or 4x4 is not destructive will not work. We need dirt on the enemy. They spike our trees, so we should put arsnic in their granola. They booby trap our trails and we should torch their moca java hangouts. Why should we retreat? You can put a nice fuzzy spin on it however you want. Sure ok, if our bikes are ultra quiet and every guy on a bike is super nice and friendly out on the trail then its all going to just go away...... Aint gonna happen they have it out for us no matter how we try and suger cote our lifestyle.......

Dont get me wrong I do try and do the right thing now. But its gonna be differnt 10 years from now and what Im saying now I might have to be doing.

Seth for President!


Posted by: zcookie49---------------------

I dont know anyone personally that has stepped up the pipe on the 400/426 for the hp gains are barely noticeable....
I on the other hand put a pipe on my 250F, the ratings are 3-4 more hp, I dont know what it really is, but I can tell a difference with delivery then over the stock pipe. If the gain would be 1 hp, i wouldnt have bought it, but since it was alot more and had a spark arrestor in it, I thought it would be a good idea, plus it would benefit with the spark arrestor on certain areas. Now i have to worry about db reader......
Yes, the pipe is slightly louder.
I guess I suck.
I have to agree with the point 380EXC man made about giving in...
like the old quote says, "you give someone an inch, they will take a mile from you"
see, its not good enough that the greens have won and will be taking away 2 strokes from us, no, now lets move on to something else, since we won that battle, lets move forward, lets win the war.
.
We all have the face the fact that we live in America, and no matter how great our country is with freedom, people will always make a case over something they dont like.
.
I dont want to ruin our sport, I comply with no trespassing and am not sue happy.
.
Probably in 10 years, are bikes will be solar/battery powered. there will be a big issue about battery leakage on trails.
lets just face the music, motorcycles, whether loud piped harley hogs, speed gobbling crotch rockets, or earth eroding dirt bikes are not accepted by many americans and have a sterotype labeled to them.
.
I understand the orignal thread though
.
I dont want to screw up anything


Posted by: bwalker---------------------

IM with Ivan. I doesnt have to be obscenely loud to sound good. Besides IMO a 426 with a pipe sounds like a a continous fart from a 450lb fat man after a all night chili and beer binge.


Posted by: James---------------------

Take a hint from the gun battle that compromising doesn't work...they will always push for a new compromise.

I can say from my own experience that pipes can make a huge difference in how a bike runs. I simply switched the 2001 baffle on my xr400 with a 96, removed the snorkle, and rejetted and the thing runs a world better...night and day. It is louder, but it will start now, has the power to pull itself up a hill, and most likely wont get me killed for lack of acceleration over a jump. My 650l was UNSAFE in it's stock EPA condition. TOO LEAN, would stall in most off road situations, and couldn't pull itself out of the way of a school bus.

I can see making reasonable accomodations. I will also agree that most of these aftermarket pipes are too loud. But just like a loud pipe with no place to ride sucks, a super restricted quiet bike that won't go anywhere (or is dangerous) would make me just as miserable.


Posted by: VintageDirt---------------------

Quote:
Originally posted by 380EXCman
But what really pisses me off is all the people that want to meet our enemies 1/2 way. No matter what we do there will always be someone that does not like what we do period. And if we continue to meet them 1/2 way we will negoitiate ourselves out of exsitence.
Right on! I'm all for quiet bikes too. But the truth is, it ain't about noise. Even if dirt bikes were totally silent, we'd still be fighting the tree huggers. I remember when it was perfectly legal to ride bicycles in wilderness areas. The rule that stated "no motorized equipment" was changed specifically to exclude bicycles and hang gliders.

So don't tell me it's about noise.:think


Posted by: Bobt250---------------------

As James said, some bikes are obviously choked to death but I have a story to tell.

A friend and I once had XR200's. They were dead even in a drag race. I installed an aftermarket cam and it got slower, I started losing the drag races by a bike length. I thought "with that cam maybe it needs "opened up"". I removed the stock huge quiet silencer. It got even slower, I lost by two bike lenghts. I tried a couple of different silencers I had laying around, none put me back in the race with my buddies stocker. I ended up returning the cam and putting the stock silencer on.

We ran studded tires one winter and my buddies tire rubbed the silencer enough to put a hole in it. His bike immediately got slower.

What does this mean? Well, some aftermarket pipes/silencers may make a bike run better but I learned that contrary to popular opinion simply "opening up" a four strokes exhaust system doesn't neccessarily make it run better. The dynamics of exhaust scavenging are complex even in a four stroke. The systems the factories put on are well tested and usually provide the proper resonance characteristics for optimum (or close to) performance. I'd say that companies like Honda etc. have more money to spend on R&D for effective pipe design than do most aftermarket companies. I could be all wet, I'm not any authority on pipes or anything else for that matter. Just some observations I've made,

loud doesn't mean fast.


Posted by: RTKLR1---------------------

A loud bike makes people who dont care either way about motorcycles dislike them.


Posted by: NVR FNSH---------------------

Quote:
Originally posted by RTKLR1
A loud bike makes people who dont care either way about motorcycles dislike them.


The environmental extremists are using noise to gain support from the people that don't really have a problem with OHVs being a legitimate form of recreation IF they weren't so damn obnoxious. Quiet pipes are not for appeasing the extremists,they are to keep the reasonable folks on our side of the fence. I ride with a married couple - he rides a WR426, she rides a WR250, both bikes run uncorked stock pipes. Guess what? They both wear ear plugs because the noise gives them headaches. Gee, I wonder what it does to the people that hear them from a ridgeline away?

Brian


Posted by: zcookie49---------------------

wearing ear plugs with a motor between your legs???
.
I agree with the gun quote and compromising.. It will never be enough, once they win the noise pollution rule, they'll move to the next topic. Injuries, dirt bikes cause injuries or something absurd like that...
.
speaking of guns, HK (gun maker) has a pretty good slogan for their high quality pieces.... "In a world of Compromise.... SOME DON'T"



Posted by: zcookie49---------------------

oh yeah, I think I remeber a sticker saying "Loud Pipes Saves Lives"
.
Meaning, you can hear someone coming and watch out....
LOL just kidding...:confused:


Posted by: Dan---------------------

I plan to join AMA this year and i didnt know about a noise limit. Is there one or if there is what is it, becuase i have an FMF power core 4 on my yz400f. i and know it will not pass the db limit.
thanks for any info.


Posted by: IBWFO---------------------

I guess I'm part of the problem too, since I also agree with Vince.
Some of you make me laugh! Use your head! When you ride and need to make the bike quiet,......DO SO! If your on the track then have fun.
Oh and I'm also one of the Harley guys too, live in a nice neighborhood and have short fat drag pipes on my bike. It will set off car alarms from 25 ft!
I don't ride around my neighborhhod doinf this because I use my head and am considerate of others! I expect YOU to do the same.
I don't need the AMA making decisions for me, and neither do any of you.
The AMA is in trouble.


D


Posted by: maicomotoman---------------------

What cracks me up is that my Husaberg starts just fine and runs strong right out of the box. No "uncorking" necessary. It also has a better powerband than the 'bergs with aftermarket exaust systems. No need to change it. It is also only slightly louder than a stock XR. What also cracks me up is that Yamaha(or Suzuki) can't get thier s#%t together enough to build a bike that will run well in stock trim. It kindof bums me out that people who ride in the woods can't live with 1 or 2 horsepower less(or maybe the aftermarket people just assume that they won't?) and run a quieter pipe. I LOVE dirtbikes but I think that "uncorked" YZ/WRs SUCK. This isn't about your freedom. If you wan't to defend your freedom there is plenty of work to be done to protect our trails. Being loud and obnoxious is no way to defend our rights to our own land. I can be O.K. with loud bikes at a remote MX track, but please use some common sense and consideration in the woods. Oh yea, Harleys with straight pipes SUCK too!


Posted by: IBWFO---------------------

Maicomotoman proves MY point and Many others on here!
You stated that your "Berg" is quiet and runs great without an after-market pipe. Then, you follow with the YZ/WR (Yamaha or Suzuki) "uncorked" suck!
This is exactly the kind of journalism that ruins all of us.
Do you truly know what your talking about? Is the CR or the KX "More" quiet than the Yamaha and the Suzuki? Is all your comparisons based on that of the "Berg"? If it is, no wonder your having problems. How Short-sited and selfish! If Joe biker decides he wants to buy a pipe and silencer for his bike because he "Wants" to, are you saying he isn't entitled to?
It's folks like you that make "Blanket" statements like you have, with little background knowledge that ruin it for the rest of us.
I can tell you wouldn't be the kind of friend that I would ride with!
Get a Dictionary and look up the word "COMPROMISE"!

D


Posted by: maicomotoman---------------------

I meant to say that the uncorked Japanese suck because they are too loud. I think that I do know what I'm talking about. I'm not saying that "Joe biker"can't run a loud pipe, All I'm saying is that if you want to ride in the woods (or on the public streets) you should be considerate of the other users of said woods and streets. I am quite aware of the meaning of the word "compromise". Compromise is about settling a dispute by mutual concession. In this case I think it means doing what you can to lessen the impact of dirtbiking for the good of dirtbikers everywhere. I have enough experience in the woods to know if you ride by on an excessively loud bike, people will have a negative reaction. If you do your best to pass by other forest users as unobtrusively as possible, you might just get a friendly wave and a vote for multiple use when the USFS comes asking for public opinion. I love trailriding, and refuse to idly watch a bunch of loud, overly agressive yahoos ruin it for the rest of us. This land is my land. This land is your land. Learn to compromise and share it or be locked out of it forever.


Posted by: IBWFO---------------------

Agreed!
I still love my Harley and the "Loud" pipes but I do use my head!

D


Posted by: needsprayer---------------------

"otherwise we will eventually be forced to race electric scooters around the parking lot of the local walmart" :D

I would like mine with a fuel cell that uses water for gasoline, goes from 0-90 in 4.6 sec and is stealth quiet.

Will this ever happen, you betcha. In fact, this baby may not even need wheels. Uses magnetic repulsion and gyroscopic stabilizers.

Not in my lifetime, but this is the "scooter" of the future.

Just like four strokes vs two stokes, the technology will catch up to the demand.


Posted by: maicomotoman---------------------

I will be fine with a fuel cell that makes those kind of numbers , but can I have one with wheels? Pleeze?


Posted by: needsprayer---------------------

"but can I have one with wheels? "

I thought about the fun factor after I made my post. Wheels would be available, and flats would no longer be a problem. Just fly out.


Posted by: LongTime---------------------

In reference to the "cowards" comment, believe it or not, I'm not one to shy away from fighting for a belief . This is one area, though, where I think we should be cooperative. For two reasons: a) they have a point. For those of us who ride in crowded national lands, I can see that those are the last places for others who want to hike/find some peace and quiet. And to them, a group of brightly colored riders minding their own business with quiet bikes is MUCH less intrusive than the same group making more noise than an international airport [especially if they're a few hundred yards or more away]; b) it's not something that really impinges our ability to enjoy our sport. If there's a scale, say, of Zero = no riding; and 100 = perfect riding, then, to me, the number I'll hit on that day's scale will be far more influenced by the landscape; the weather; my riding partners; my personal rhythym that day; and my bike, generally, than it will be by which pipe I put on my bike that day. Simply put, if my day's gonna' be one of those wonderful, over 90-on-the-perfect-riding meter days, it's gonna' be that regardless of the pipe I put on.


Posted by: Kramer---------------------

Well said Longtime!

I proved that to myself this summer. I had previously only ridden uncorked. (WR400). Tried the vortip but it just didn't have the zip I was used to.

I like it quiet, so last spring I committed to not riding uncorked even once. All summer, and never came up short on power. Never missed it.

Over Christmas, a friend came to visit, who hadn't ever ridden a modern 4 stroke and of course I wanted him to get the full experience,... out came the vortip. Yes it changed the character of the power, but the bike was only marginally faster. If you dragrace you'll miss it, otherwise not.

On top of that, I could actually hear the 3rd generation echo off the surrounding hills. Not cool, considering that sound traveled somewhere around 4-5 miles and echoed twice, still loud enough to hear. Anyone that would knowingly operate like this is ignorant and inconsiderate toward everyone. NOT just toward the environmentalist. They are every bit as bad for the sport as cooler-toting quads are for their sport.


Posted by: slowbutthere---------------------

There is no question that there will always be a number of eco types that will not be happy until they are the only people allowed in the woods. But I believe they represent a very small minority of people that use the woods. It truely is a battle for the hearts and minds of other people that use the woods(fishermen, hunters, hikers and campers). We need to not comprimise on land closures, but not shoot ourselves in the foot by offending other multiple use users.
Let me tell a true story that illustrates what I am talking about. I heard this story from the hiker not the dirt biker. A group (25-30) girls with adult leaders planned a twenty mile hike here in North Idaho on one of our premiere single track trails. It is a trail that crosses a large creek more than a dozen times. These water crossings are typically 15 to 30 yards across with water 2+ feet deep in places. On day as this group of hikers made there way down the trail one of the adult leaders fell behind and got seperated from the group. She came to a water crossing that looked deep and swift. She was afraid to try and cross the stream by herself. After standing on one side of the creek for almost 30 minutes a couple of "nice boys" on dirt bikes pulled up and asked her if she needed help, she explained the problem. They got off their bikes and waded across the stream with her and then rode ahead and informed the main group of their straggler. The whole group of hikers was very much appreciative of the dirt bikers for their consideration and help. If we want to win this battle we need alliies and we need to do things that shows the general public that we truly are good stewards of the trails that we love. IMO that means limiting the amount of noise our bikes make. Not because the law says so, but out of consideration for others useing the trails. I have ridden that trail for twenty years and I want to ride it twenty more.


Posted by: mkuder---------------------

I agree with the sound issues as I live in a rural community where the homes are on 3 acre tracts. I had a neighbor come over to let me know she didn't appreciate the noise that my bikes were making. So I comprimised with her and agreed to only ride on two set days a week at a set time. If my bikes had been quiet this wouldn't have been a problem. I ride a 1998 KTM 125SX (stock exhaust) and a 2000 Suzuki DRZ400s (I have replaced the stock silencer end cap), I'm guessing that I'm pushing the 100db mark, but I can put the original cap on and stealth mode begins. I have explored the aftermarket exhauts for the DRZ and up untill moving here wasn't concerned about the noise. My main concern was for weight savings, so I just live with the extra weight until I find a quiet replacement.


Posted by: snackbar54---------------------

Damn, you guys need to get some country of your own..I love going out and bogging around our family farm in my 76'chevy with nothing but straights coming out...I am the loudest in my county except for the 15 plus 2-stroke motorcycles from kids who graduated high school and work construction!!..listening to those babys get up and go is just a relief to know that we can do what we want, when we want, and everyone else can go live in the damn city...I tell you what, Iowa does mostly suck, but it's great for some rip roarin' good times


Posted by: Bluethumper---------------------

well heres my 2 cents....

I own one off those loud 4-strokes. a WR400 with the stock exhuast from the factory and the baffle in it, I might as well have bought an XR. when I removed the baffle it is loud!!! but the performance increases are huge. so I bought an FMF power core 4 exhaust and it is a little quieter but the performance did not change. IMO I wasted $200.00 buying that exhaust unless I consider the wieght lose. If I pipe manufacturer made a pipe that was quiet and held up the there claims of performance I would buy that pipe.

As for compromising with the enviromentalist. we are and will be the only ones meeting in the middle. the more we compromise the more they demand!!! they want wilderness areas that no one can use... we gave it to them, now they want more!!! they want those smoking 2-strokes off of public land... thats is coming soon. we design a 4-strokes that can perform on a track as well as a 2-stroke.. now they are to loud. where will it end!!!! I can see me now rolling out to the desert to bang some whoops on my electric powered mini-bike. and the enviromentalist complianing about how much natural resources it takes to charge the battery on my bike!!!

In closing I'm with 380. I'll roll past thoise signs if they start posting them in my riding areas. and blow by johny and his Db meter if my bike is to loud!


Posted by: Jay-R---------------------

The environmental extremists will never be happy until most of the US is in forest lands where no one can set foot. And they are able to use our tax money to do it. I often wonder why the public abides by these eco-nuts' views. Obviously, most of the general public who enjoy the outdoors through various activities, do not agree with the extremists. Since they take away their rights too. But it is easy for the extremists to gain support from people living in the cities who rarely venture into the wilderness.

I agree with the AMA sound limit, only because I believe that it will force aftermarket pipe manufacturers to make quieter pipes. This may in turn gain us some support from the people who are sitting on the fence about the dirt bike issue. I do not feel that we are compromising with the extremists, but we are trying to gain support of John Q. Public who has nothing against dirtbikes, except the noise.


Posted by: wayneo426---------------------

Quote:
Originally posted by Jay-R
But it is easy for the extremists to gain support from people living in the cities who rarely venture into the wilderness.


Well spoken. There are thousands of inner city folk who contribute to these eco-nazis while not even knowing the scope of these org's activities. Scary to think they get millions by just sending out stickers upon receipt of donations.


Posted by: LJW---------------------

Check out:http://www.dnr.state.mi.us/ParkDeta...ID=63&Mode=5554

I do not own a bike that will pass this test, and I'll bet most of you don't either.

Roll past the signs and blow by John Law's meter? Bold talk.


Posted by: ballistic---------------------

I run a BigGun Quiet series on my DRZ400e. It is 6 lbs lighter than stock, and has decent performance boost for a pipe only a little louder than the super quiet stocker. Its around 94db apparently. I also have the race insert for my BigGun. TOO LOUD!! I hate it, and my kids hate it. But lets put it this way: I wear earplugs all the time when I ride, quiet or no quiet pipe. I feel less fatigued and all around better than not using. Those of you who have discovered the "secret" of earplugs know what I'm talking about. Those of you who think thats nerdy must also think sidepipes on a Gremlin is cool. Just kidding, but you dont know what your missing.

Come on you pipe maker guys, put your RD to work.
Heres a free idea: stick a huge whistle insert thing into end of pipe. It converts the low frequency THUMP (low frq travels far) into a high whistle note :D
Heres another: never mind a vortip, stick a 36 inch piece of 1 inch rubber hose on the end of pipe. Let that sucker flop down and blast the noise into the ground:confused:


Posted by: bud---------------------

-


Posted by: Rodzilla---------------------

Quote:
Originally posted by Jay-R
The environmental extremists will never be happy until most of the US is in forest lands where no one can set foot. And they are able to use our tax money to do it. I often wonder why the public abides by these eco-nuts' views.


To be honest I think a LARGE amount of the "outdoor using public" never gets much past the campground. So if it "doesn't affect them" (or so they believe)

But I have to agree, when I'm camping I don't much care for the sound of bikes and I LOVE TO RIDE. When I'm in the boonies I want the same peace and quiet we all want.


Posted by: Jay-R---------------------

Quote:
When I'm in the boonies I want the same peace and quiet we all want.


I have to agree. There should be areas set aside for ORV's as well as areas for peace and quiet. This is a large country and there is plenty of room for both. I mean come on, wouldn't it be nice to have 70% quiet to 30% ORV on the public lands. One of the reasons we make so much noise is that we are confined to a few small ride areas.

One of the ride areas where I used to go had a very nice camp ground and you could ride to the trails right from your campsite. But, the people who went there just to sit outside their campers and to watch other people complained about the riders. We tryed our best to be courtious, but they did not like us there. I was thinking to myself, there are thousands of campgrounds where no riders are allowed, and very few where we can ride from. To make a long story short, they built a new campground for the "do nothing" campers, and made the campground next to the trails a wranglers camp for horse riders. So, shortly after that, the horse riders complained about the off road vehicles. In short that great ride area is now for horses and hikers.


Posted by: NVR FNSH---------------------

How many of you complain to yourself (or the owner, hopefully) when some jack ass (fellow dirtbiker) has their obnoxiously loud construction site generator running in the campground at mid-nite? Gee, think that the non-riding public might have the same opinion of loud bikes sharing a campground/riding area?

There is a post somewhere on the site saying a guy got measured at 111db - that is friggin' ridiculous. How far away is that bike going to be heard?

Brian


Posted by: RetSenior---------------------

Brian, what did the KTM come in at about 91 db's. And performance is way down on it, huh!


Posted by: NVR FNSH---------------------

smartass. I got smoked by way too many STOCK KTM 520s this weekend at Reno for people to even begin saying that a quiet stock bike is underpowered and they have to install a loud aftermarket pipe to make the bike work properly.

This is one of my pet peeves - sorry.

Brian


Posted by: RetSenior---------------------

Yea but at least you had fun in Reno even with your dismount. And hey I even agree with you.


Posted by: NVR FNSH---------------------

It wasn't me, I wasn't there - prove it was me Who told you about them? I didn't see you there and so far I haven't seen anything written....

Brian


Posted by: James---------------------

Quote:
Originally posted by NVR FNSH
smartass. I got smoked by way too many STOCK KTM 520s this weekend at Reno for people to even begin saying that a quiet stock bike is underpowered and they have to install a loud aftermarket pipe to make the bike work properly.

This is one of my pet peeves - sorry.

Brian


Maybe a stock KTM 520 isn't underpowered. I guess we'll all be riding KTM 1000s to get the power we need after they are all plugged up so we don't make any noise in the woods. You shouldn't have to ride a 500cc + machine to be able to climb modest hills or jump a 20' double. Go ride a stock XR250 and see what you think of stock bikes. Reason I keep referring to XRs is that they currently meet the 2006 CARB standards. I am not certain that the KTMs do.

"LOUD" aftermarket pipes suck, I agree. But many stock bikes run like there's a banana stuck in the pipe. I stand by my comment that a stock XR400 is way too plugged up and does not make enough power as delivered. To make a broad statement that they aren't is ignornant....one of my pet peeves.


Posted by: Bobt250---------------------

The biggest reason an XR250 is slow ISN'T because it's quiet.

"nuff said


Posted by: maicomotoman---------------------

Quote:
The biggest reason an XR250 is slow ISN'T because it's quiet.
The same could be said for the XR 400. As for the YX/WR and DRZ...they could be quiet AND fast if they were engineered to be. The euro bikes have proven that it can be done because noise is more of an issue in Europe. I haven't heard/ridden any of the other euro bikes, but I know the KTM and the Husaberg are quiet and fast. Those bikes cost more, but when you look at the components and design, you can see where the money went. You don't need to replace/modify the airbox/pipe/silencer/chain/bars. They are fast and light (and quiet)right out of the box. Don't get me wrong, the Japenese motors are great, but they could be made to work more efficiantly. When it starts costing aftermarket exaust manufacturers market share and the Japanese motorcycle manufacturers are forced to engineer the bikes without throwaway exaust systems, maybe they will catch up with the euros. Until more noise is made about noise, expect to see the same attitude from said pipe and bike makers: "these hicks don't care about noise, let's just continue to take the easy route to lining our pockets" That's the way I see it , and that's the reason I don't support them or the people who cry "It's my right to run a loud pipe". No, it's NOT your right! You are infringing on the rights of others by making that excessive racket. Do you really think that you need an extra 2 horsepower out of your 40+HP bike? For what? In my opinion, being a considerate user of the forest is WAY more improtant than a modest power gain. I think the majority of trail riders are bothered by noisy bikes. The minority, who refuse to consider others, are making the sensible ones look bad. Here's an idea: all of you guys who like the sound of your loud pipes can run a hose from your pipe into your helmet. That way you can hear it at full blast all day, and not bother anyone else. Or you could just run that hose right up your


Posted by: James---------------------

LOL Maicoman,

OK, OK, point taken...and I agree with you guys in most respects. But, do we really want to see dirt riding become a situation where we have to buy $6000-$8000 (or more) bikes to ensure we are quiet enough to not disturb anybody and still have suitable power to do more than casual trail riding?? One way of killing an industry is to price everybody out of being able to participate.

I'll also agree that XR250s and even 400s weren't engineered to be fast. BUT, they are the kind of bikes that get people out riding and considering the simple maintenance and lower price....keep people riding. And they are capable of going reasonably fast (I honestly prefer my CR250 but being fair to the others....) My point on those is they come stock very quiet. For not much more noise, you can increase the power very noticeably. But even that slight change will make the bike illegal if we start seeing 90db limits or lower (don't think they'll stop at 96). The real point is that these bikes in stock form currently meet the minimum standard that is going to be imposed on all of us. Choke your YZ426 down to meet those noise and emissions standards and see how well you like it.

All I am saying is, at some point, whether it be 99db, 96db, 50db?? we have to say enough is enough and realize that no compromise is going to be good enough until we can't ride anywhere.


Posted by: maicomotoman---------------------

Quote:
All I am saying is, at some point, whether it be 99db, 96db, 50db?? we have to say enough is enough and realize that no compromise is going to be good enough until we can't ride anywhere.
I agree. I am just saying that if the demand is there, the manufacturers will make it happen. I think that if they are required to find a way to make +40HP/-60db dirt bikes, they eventually will. They are not required to make good running, quiet bikes now. They have to make them quiet, but they also know that people will just remove the baffles(hell, they are MADE to come out!) and ride them. I know a lot of guys who ride quiet bikes without being forced to. They LIKE it that way. Unfortunatly, the only way to quiet down some guys is to have a park ranger check all the bikes with his little sound gun. This costs us money. It also will force bike and pipe makers to get thier s#%! together. I'm not a fan of rules and regulations, but sometimes they are necessary:mad:


Posted by: vince321---------------------

Maicomotoman........

Give me a break. Just because you think it's your right to impose the sound levels that YOU think should be enforced, doesn't mean we have to or shoud agree with you. Once an agencey determines that your bike is too loud and that they wan't to stuff up your muffler, how will you feel?

If your looking for a quiet sport, one that won't impose upon your right to peace and quiet, why don't you take up basket weaving, or golf or any other sport that doesn't involve gas powered engines. Of course, while golfing, you may run into people who smoke cigars and then they would be imposing upon your right to breath.


BTW - I think we are still missing the point. These agencys are not interested in sound levels. How many mountain bike trails have been closed over the past few years? THEY WANT TO SHUT US DOWN. As I see it, people who are gung-ho in thier support to accept any new rules and regulations regarding sound levels are helping to push forward this agenda. There will come a time when what you feel as though your rights are being imposed upon. When this happens, I will be there backing you up regardless if I agree with them or not. This is how it should be............


Posted by: James---------------------

Quote:
Originally posted by 96whyzee125
FYI
The biggest reason any XR is slow ISN'T because of it's exhaust. It’s an XR.


Geez,

Another illiterate who completely misses the point while calling people on grammar. I never said the XR was slow because of it's exhaust, I said it was SLOWER and unacceptably so. Not to mention the hard starting. Besides, I'd be willing to bet your YZ needs to be muffled a lot more than my unplugged XR (your harley too no doubt).

Next time you want to climb on a soapbox, how about filling it with water and sticking your head in...might muffle the noise. And since this is a family site, how about laying off of the profanity while you school us on our grammar?


Posted by: zcookie49---------------------

what the difference being at a red light next to a Harley or next to a Honda Civic with the bass rattling your car? So that is monitored too....
What the difference of being next to a loud rig downgearing with a load on the rear.
This is just too ridiculous to carry on.


Posted by: James---------------------

Quote:
Originally posted by maicomotoman
96wheezy : Expressionism is a style of painting, Mr. Grammer guy, I think that you probably meant to say expression. I don't know what GMAFB is supposed to mean... Is it a (h)arley thing?


GMAFB is one of those expressionisms they use right before they hit you with a chain because you are giving them mean looks as the loud exhaust on their harley is shaking the fillings out of yer teeth.

By the way Wheezee, I did start the XR topic so your comment was a result of something I posted in the past. The "hysterical" part about these posts (as you so eloquently put it) is that you seem to resort to threats when you can't intelligently counter someone's point. What's the matter, you can't take it as good as you can give it??

ex·pres·sion·ism n. A movement in the arts during the early part of the 20th century that emphasized subjective expression of the artist's inner experiences

Consult a dictionary...says nothing about venting, using profanity, or staying in school. The word you are looking for is "expression" as in "it was just an expression."


Posted by: VintageDirt---------------------

Now boys, let's not get into fisticuffs here.
You want to practice your pugilistic arts? Go tell Scott Summers that XRs are slow.


Posted by: Bobt250---------------------

Scott Summers is a real man, he kicks ass ON his motorcycle.

He might even be able to make a hARLEY go fast.

Well, that would be asking a bit much from even him.

:-)

Peace out.


Posted by: VintageDirt---------------------

hEy, DO anY of you Fellers remember that aPriL fools issue of Dirt Bike where sUPER hUNKy borrowed a full dress hARLEY and had jIM HoLLy (same guy that does the live webcast for CCE supercross) do jumps and wheelies on the thing? That wuz a good'n, no? Roland wouldn't let 'ol sUPER run the hARvey on the cover.


Posted by: James---------------------

Well I don't think it would be proper to issue or accept challenges of that sort here so I will withdraw from any further conversation with the literary genius in public.

Hey Vint,

Yu mean dat SOOPURR HUNKEE twas rely goner jurmp a hARVEE dONALDsen?? Naaaaaa..al heck!!


Posted by: NVR FNSH---------------------

Legit question here...

do supercross bikes have to meet a sound limit? The races are AMA sanctioned, correct?

What about the GNCC races? Don't Lafferty & Watts run stock KTMs w/stock exhausts? If they don't need more power (at the cost of a louder exhaust) then I find it hard to believe that most of us here really do.

Brian


Posted by: James---------------------

Not a legit comparison.

Supercross bikes and any other AMA sanctioned motocross event has 100 db limit for closed course competition. The proposed limit for 2006 is 96 dbs. for non closed course (I don't know if the closed course limit is going down also). Some bikes come choked down to 82 dbs. currently. I don't know what the KTMs are like stock but it all depends on what bike we are talking about when we talk "stock" and what stock is going to be when they impose additional sound restrictions. It also depends on how much louder than stock you are talking about.

I guess we could sit here and generalize about it and over simplify forever and you'd still find it hard to believe. SO choke down a supercross bike another 4 or 5 dbs and see if it has enough power. I bet more than one rider would complain.


Posted by: LongTime---------------------

Well, well . . . this certainly has turned into an interesting thread.

The real grammar police watch, by the way, and may not necessarily agree with the "grammar posers".


Posted by: mtngoat---------------------

Well, I didn't intend to stir the fecal matter, although I've been around long enough to anticipate much of the reponse. I wanted to promote more deliberation. I've thought about it and done some research.

First, the feeling that giving an inch forfeits a mile is bumper sticker logic. It's never that simple in our society. The real "battles" are fought at much greater levels of detail. I believe people like the author, Bill Dart, understand this and employ thought more than emotion to protect our riding interests.

Bill's right, it's coming whether we like it or not. I've heard Rangers in my area will be receiving new equipment and will enforce. LJW posted a link that I'm re-posting to reflect that prediction:
http://www.dnr.state.mi.us/ParkDeta...ID=63&Mode=5554

One battleground will be the RPMs at which sound measurements are made.
Accepting the likely method of an SAE 20" measurement at 45 degrees off the pipe, the RPMs offer a way to offset what could become an unreasoanbly low dB level. Seems one approach under consideration is to set RPMs at the half-way point of the makers peak horsepower. This may spell trouble for hi-reving bikes, like Yamahas.

Another battleground will be technology. Here's a link to sound measurement issues encountered in Europe with motrocycles:
http://itctraffic.com/noise.htm
The short version is that noise citations will likely be challenged similar to radar speed tickets (method and calibration issues), but it's inevitable it will be solved technologically. I'm concerned that over zealous Rangers with new electronic toys will "sway' measurements the wrong way.

On the sound mitigation front, I looked into exhaust design; here's an informative link:
http://www.howstuffworks.com/framed...hausttheory.htm

Seems many stock bike exhausts have followed the "Restrictive" design approach. Aftermarket mostly employs the "Absorbtion" design approach (free flowing, noisier). What's seen little development iin dirtbike pipes is "Reflective" design which seeks to cancel out sound waves with less Restriction. That's what I think we should demand as pipe buyers. It's not simple and will require clever engineering to keep pipe size and weight down, but I think it can be done, if demanded. Might finally justify the prices we pay for some of those pipes.

I found an interesting link on exhaust design for Harleys. Personally, I like the sound of a Harley, not the noise level of many aftermarket pipes, but that visceral tonal quality that comes from the engine. Increasing noise for the sake of noise takes me back to the days I used clothepins and playing cards on my bicycle; I grew out of that. Anyway, here's the link that discusses Reflective exhaust deisgn:

http://www.howstuffworks.com/framed...motorcycle.html

Finally, I'd like to know if any of you have actually measured dBs. I'd like to see more dB awareness and if any of you have or have access to a dB meter, please measure (using SAE 20" and an RPM meter, stating the RPMs; I suggest idle and the half-way point discussed above) and post. It may be time to let this post die, but the issue will continue with or without us. Maybe we should start another post and keep a log on forum member measurements indexed to bikes and specific modifcations. We'd be better informed and better able to fight the real battles.

p.s. White Bros sells dB meters and inductive RPM guages are available at many auto parts stores.


Posted by: Rodzilla---------------------

A year or so ago there was a great post about noise and how the dB scale works. I wish I could find it, Guess I'll have to work harder...

I think that it is important that pipe buyers realize that the dB rating scale is not linier, it is a expeonetial scale.

The point being is that if you look at the pipes and say (just for argument) that your stock pipe is at 92 dB. Then the aftermarket pipe you want is 96 dB, it's not as simple as "Oh, it's only four steps louder" because the dB scale is not linier 96 dB is a MULTIPLE of the lower number

OK I'm not an engineer so dont't blast me if I'm talking out of my

But some better education on this wouldn't hurt anyone.


Here I stole this from an earlier postL

Keep in mind that dB measurements are a logarithmic scale. This means that for every gain of 6 dB, the sound energy doubles. So, 97 dB is almost 1/2 the sound energy of 100 dB. I don't have any test data to back this up, but I would suspect the sound energy to be the driving factor when considering how far the sound will travel (and how many people will be bothered by that sound). So, when you see a "modest" increase in sound level of 2 or 3 dB, it is equivelant to 30% to 50% more sound energy.



Rod


Posted by: NVR FNSH---------------------

My '99 WR400 with stock exhaust/Thumper Racing Quiet insert was measured at 95dBA by the Rangers at Middle Creek. 95dBA is a little louder than I would like but is a reasonable level as far as most people are concerned. 96dBA would be/is acceptable to me w/o being too restrictive and causing performance problems.

Rodzilla is correct - 6dB equals a doubling of SPL. Also, for the most part (surroundings do affect the reading) the SPL drops 6dB per doubling of distance. Most people have a hard time distinguishing an increase/decrease of 2dB. 3dB is where most people can start to tell a difference.

Where we, the OHV community, may run into problems is that a lot of locales use the SPL at the property line to define too loud. I can see, or should I say hear, it now - buffer zones in OHV areas to prevent too much noise from crossing the 'property line'. You can guarantee that the buffer zone will come out of the riding area NOT from the adjacent properties. I experienced this first hand 10 yrs ago with the Garcia Ridge trail in the Los Padres NF (San Luis Obispo/Pozo area) - the environmentalists wanted Garcia Ridge closed to vehicles, street legal & OHV, since it was the border of a wilderness area.

The noise issue IS NOT a new issue, it's been around for a long time and it's not going away anytime soon. In order to preserve our hobby we must police ourselves and be good neighbors. I don't see how a 104dBA exhaust can be considered a good neighbor/proper trail etiquette(sp?) even when you shut off the engine when you SEE hikers/horseman/mtn bikers etc. My bike can be HEARD a lot farther away than I can see.

Brian


Posted by: RetSenior---------------------

Hey Brain, at least you know when Howard is riding on the other side of the ridge or mountain.

I went and bought yesterday a Radio Shack Digital Display Sound Level Meter to test on my 2001 KTM 520 EXC and I could not get it to go over 96dB's through out my RPM range. My bike is a little over 1 year old and has about 2000 miles on it. I have yet to do a repack but I guess it's time to get my 91 to 92dB's back. Here's a link to the model Sound Level Meter I bought http://www.radioshack.com/product.a...%5Fid=33%2D2055


Posted by: mtngoat---------------------

Here's a link that explains the dB scale:

http://www.howstuffworks.com/question124.htm

OSHA tends to target the 85-90 dB level as hazardous (also considering length of exposure).

Good thing for DRN, it may be the only way we can communicate as we dirtbikers age into deafness.

Thanks for the dB measurement feedback and the Radio Shack referral. I'm gonna buy a meter and start taking measurements. Any further technical insight would be appreciated.


Posted by: vince321---------------------

I just returned from riding San Jacinto in Spendora and found it interesting that they did a sound check of thier track and found that during a race, with fifty bikes at a time, the decible level at the enterance to the park was 80dB. It's probably 100 yards or less from the enterance of the park to the track.

I don't know what this means, only that I found it interesting and much quieter that expected.


Posted by: NVR FNSH---------------------

I did some sound testing at a previous job and basically it's like statistics - you can make it say whatever you want.... Seriously, there are a ton of variables - temp, humidity, trees, wind, ground condidtion, ambient noise etc - that affect to measurements unless you testing in a dedicated test chamber. Remember, distance helps - -6dB per doubling of distance - and that dB doesn't just add together - 2 100dB bikes does not equal 200dB.

Brian


Posted by: Rich Rohrich---------------------

This is an important subject, and as far as I can tell there are no simple answers. That said, the next time I have to spend 20 minutes editing a thread because a couple of jerk-weeds feel the need to vent we'll have a few less DRN members.

Play nice kids, or go somewhere else. I have better things to do then field complaint e-mails and clean up after you.


Posted by: maicomotoman---------------------

Sorry everyone about some of my more abrasive posts yesterday. I didn't mean to get personal, or hurt anyone's feelings. Too much coffee maybe...I realize that we need to stick together, and try to come to some sort of agreement between ourselves before we can defend our trails effectively. Thanks Rich, for your work here. I'll try to take a minute to think before I make smarta$$ posts in the future.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by maicomotoman
I'll try to take a minute to think before I make smarta$$ posts in the future.


There is nothing wrong with a well crafted smartas reply. All I ask is you guys keep it civil.


Posted by: NVR FNSH---------------------

Quote:
Originally posted by Rich Rohrich
There is nothing wrong with a well crafted smartas reply. All I ask is you guys keep it civil.


For reference do a search on Rich Rohrich. You'll find plenty of well crafted smartas replies

Brian


Posted by: SFO---------------------

I was at a dyno shootout in Amsterdam.
It was a Harley trade show and the sponsor had a dynojet and a DB meter.
The bikes all had to be less than 95db.
The winning shovelhead made over 100hp and made less than 95db.
I was amazed to see hotrod bigtwins that were quiet.
I know we can do the same thing with these yz-f's. Quiet and powerfull.
These are great goals.


Posted by: James---------------------

When is the last time you saw a 250lb Harley? I suspect if you had to get the weight down enough to jump triples on those shovelheads, they wouldn't be nearly as quiet.

My car is real quiet too but it has the extra CCs and 4 wheels to haul around all of that extra muffler and sound insulation.


Posted by: mtngoat---------------------

Someone posted in another thread that the Radio Shack dB meter has an accuracy of 1-2dB (seems like a little until we consider exponential gain). I checked on the Intercomp meter sold by White Bros ($235 retail, ouch!!) and called the maker. They claim their unit is used by AMA and has greater accuracy. I'm expecting a spec sheet on their product. Here's a link:
http://www.whitebros.com/Completese...FS/access24.pdf

Obviously, the Radio Shack unit is a much cheaper way to give us an idea of where we are, but keep in mind accuracy and keep the measurements coming. If anyone finds other meters, please post.

I was checking out my buddy's YZ426 last night and realized his plug wire is difficult to access. I don't know how RPMs are going to be measured (inductive meters need pretty clear access to plug wires), if measured. I'd hate to think we'll be subjected to "testers" throttling our motors to their idea of half-way or whatever.

Anyway, thanks for the great responses. I think the awareness and efforts to figure this out before it's imposed on us will help our cause.


Posted by: NVR FNSH---------------------

mtngoat,
Mendocino NF uses vibration tachs that they set on the flat of the rear fender.

Below is a link to a thread a while back talking about the test method and the results from the ohter bikes that were with me that day.

http://dirtrider.net/forums3/showth...=vibration+tach

Brian


Posted by: zilla---------------------

Not only do I rememebr the story, I probably still have the issue!.. Aaahh yes the good ol days


zilla...older n dirt


Posted by: NVR FNSH---------------------

Quote:
Originally posted by JamesP
When is the last time you saw a 250lb Harley? I suspect if you had to get the weight down enough to jump triples on those shovelheads, they wouldn't be nearly as quiet.

My car is real quiet too but it has the extra CCs and 4 wheels to haul around all of that extra muffler and sound insulation.


Yeah, those KTM 520s are sooo heavy because of all that muffler they carry around. Gosh, I sure am glad that Yamaha made sure my WR00 doesn't weigh as much as one of those quiet bikes with an electric starter........

Brian


Posted by: RetSenior---------------------

mtngoat, I bought a Extech Model 407750 Sound level Meter to compare to the Radio Shack one. The Extech one meets ANSI and IEC Type 2 standards and OSHA compliance testing. It should arrive in a week and I will retest my ktm with new packing and report the results. Plus I will take it on rides and make a log of different bikes I can test.

http://www.repaircalibration.com/lib/cal-tek/407750.pdf


Posted by: James---------------------

Quote:
Originally posted by NVR FNSH


Yeah, those KTM 520s are sooo heavy because of all that muffler they carry around. Gosh, I sure am glad that Yamaha made sure my WR00 doesn't weigh as much as one of those quiet bikes with an electric starter........

Brian


So how quiet are these KTMs that you all worship so? What is the actual measured db? And how many KTM 520s do you see jumping triples and winning supercross??


Posted by: ThumpinTahoe---------------------

Regardless of what is being said about noise and power, my xr400 runs sooooooo much better with my Pro Circuit T4 exhaust. Xr's are so choked up stock they can barely get out of their own way. When I pulled my air snorkel, added a uni air filter and added the new pipe it was a whole new bike. There was no way I could wheelie in 3rd without popping the clutch. Racing my buddy the other day in the desert I was able to keep my front end up with ease through all the whoop sections. My take on exhaust systems is this: If you are in the middle of no where (Moonrocks) let it rip and make all the noise you can because nobody can hear you anyway. If you are in the middle of town with Mr. CHP following you take it easy. If I let off, my bike is no louder then any other bike out there. I wouldn't own my bike if I had to keep the stock exhaust. The day they move airports out of all the major cities to keep the noise down is the day I take my pipe off!


Posted by: mtngoat---------------------

Quote:
Originally posted by JamesP


So how quiet are these KTMs that you all worship so? What is the actual measured db? And how many KTM 520s do you see jumping triples and winning supercross??


How many DRN members really need a bike that jumps triples and wins supercrossess? It's been a while, but I recall a DRN survey that established that most of us are recreational trail riders and occasional competitors. Practical "equipment" needs for most of us tend to exclude the race bikes we "worship".

It's kinda like ski equipment. Years ago, I would watch skiers purchase long GS skis used by the top racers. Theses skiers would then struggle with their competitive icons on local slopes. Their purchase was symbolic of a talent level they worshipped and aspired to, but practically inhibited their enjoyment of the sport.

The japanese makers should learn from the Euros. The KTM is a fine bike for the "masses" and those of us who accept that status towards the enjoyment of the sport. It makes gobs of power with a relatively quiet pipe. Check out Eel's post on the Husky TE 250. It's looks like another Euro bike with fine suspension, power and "friendly" noise.


Posted by: mtngoat---------------------

Thanks for posts Ret and NVR.

Ret, may I ask what that unit costs? I'm in that market and want a meter that complies with applicable standards.

Thanks to everyone offering to test and post noise measurements. This should help new pipe buyers make better decisions.

We need a practical way to maintain an online log. Keeping the thread "alive" is difficult. If anyone has some web space to "log post" noise tests, please speak up.

Alternatively, we can ask Okie to permit updating to an archived thread or??. I figure he's busy enough and we should try to solve the log problem another way.


Posted by: maicomotoman---------------------

Saturday I rode with a guy who had a Husky 410 enduro bike. I was astonished by the sound level of this bike. I couldn't hear it over my girlfriend's KDX 200. Very quiet, and plenty fast. None of the guys on faster, lighter bikes could keep up. It all comes down to how fast YOU are. Good point Mtn. Goat, if it was only about the bike, the person with the most money would win every race out there...


Posted by: James---------------------

I was just responding to another person who mentioned supercross...replace it with motocross if you prefer. This debate isn't just about trail riders as noise restrictions will affect those of us who motocross also. Actually this whole noise issue is more pertinent to motocross as there will always be private tracks to race on but we are probably going to lose the trails regardless of how quiet your KTM is. Again, this issue isn't only about noise. What may be practable for you may not be for many others. I know I need a bike that will jump large doubles and hopefully triples in the near future and a KTM520 won't suit my needs and most other people I know don't need them either. And I'd appreciate it if you didn't make assumptions about my needs. Just because DRNs survey says one thing doesn't mean it accurately represents anything.

So do I understand correctly that the KTM is now a "status" thing..is that why you promote them so? And what is "RELATIVELY QUIET", again what is the DBs?

Quote:
Originally posted by mtngoat


How many DRN members really need a bike that jumps triples and wins supercrossess? It's been a while, but I recall a DRN survey that established that most of us are recreational trail riders and occasional competitors. Practical "equipment" needs for most of us tend to exclude the race bikes we "worship".

It's kinda like ski equipment. Years ago, I would watch skiers purchase long GS skis used by the top racers. Theses skiers would then struggle with their competitive icons on local slopes. Their purchase was symbolic of a talent level they worshipped and aspired to, but practically inhibited their enjoyment of the sport.

The japanese makers should learn from the Euros. The KTM is a fine bike for the "masses" and those of us who accept that status towards the enjoyment of the sport. It makes gobs of power with a relatively quiet pipe. Check out Eel's post on the Husky TE 250. It's looks like another Euro bike with fine suspension, power and "friendly" noise.



Posted by: RetSenior---------------------

mtngoat, Here you go: http://repaircalibration.com/407750.html should arrive this week and will post results.


Posted by: mtngoat---------------------

Looks like Ret will post new dB levels soon.

The KTM is not so much about status to me as it is setting an example that a capable dirtbike (like the Husky) can be designed to comply with ever-increasing green sticker and noise restrictions. I know that's perceived only as a CA thing now, but I expect it (or similar restrictions) to spread nation-wide.

From a trailrider's perspective, I want the trails to be open, not just for my generation, but for my children and theirs. No one knows what's gonna happen, but we improve our position by being responsive to the issues we can change.

This post started with an appeal from a very informed and dedicated person trying to keep our trails open. Not many of us can commit as much time to that purpose. Bill's appeal is to get us to change a facet of our sport; the noise level. That we can do; we are bike/pipe customers and the makers will listen.


Posted by: James---------------------

we agree more than we disagree in my mind so I am calling it here. So long as my bike will pull my big butt as fast as I need to go and still be as light as the current MX bikes...I don't care if it makes no noise whatsoever. It is about performance to me, not how it sounds.

Thanks for the conversation guys


Posted by: mtngoat---------------------

Rich or Okie, whoever "topped" this thread, thank you very much.

James, glad to have you in the debate.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by mtngoat
Rich or Okie, whoever "topped" this thread, thank you very much.


No problem


Posted by: SFO---------------------

Quote:
Originally posted by JamesP
When is the last time you saw a 250lb Harley? I suspect if you had to get the weight down enough to jump triples on those shovelheads, they wouldn't be nearly as quiet.

My car is real quiet too but it has the extra CCs and 4 wheels to haul around all of that extra muffler and sound insulation.



The point I wish to make is that here in Nor-cal most all the harley builders swear by Rich thunder headers.(105db) No one makes a quiet performance pipe.
In Europe they have to be quiet or they can't ride.
Back to dirtbikes.
That is what is happening here. We in California will soon be subjected to noise screening on our off road bikes.
We can make them quiet, we will have to.
The whys or wherefores are irrelevant, we have to make our green sticker bikes quiet. And you know what happens in California is a heartbeat away from happening everywhere.(at least thats what most people are afraid of)
Noise testing leaves much room for operator error. Just watch the ama try to sound check DT bikes. (and see the commensurate modifications required to pass)
I believe with mandatory sound limits should also come a mandatory repeatable method for checking the db output of bikes.


Posted by: James---------------------

My only comment is that it would sure be nice to break this cycle of everything that happens in California happens eventually in the rest of the country. My impression of California is that it is a terribly screwed up and misguided state for more reasons than just its green sticker program.


Posted by: Okiewan---------------------

Excellent thread.
I must confess to being too loud last year, White Bro's R-4 ...
Pulled it today, stock pipe goes back on. I feel better.


Posted by: mtngoat---------------------

I went to White Bros. and talked to some of their folks. The following information is also avaliable in their online catalog at www.whitebros.com

In an earlier post, I attached a link that simply explains exhaust designs. One possible solution to the "quiet vs. performance" trade-off seemed to be Reflective designs, common in auto mufflers. This link is helpful to understand that solution and the following discussion, so here it is again:

http://www.howstuffworks.com/framed...hausttheory.htm

FMF makes the newer PowerCore IV SA pipe. In a cutaway view of this pipe, it looks like a pipe has been cut in the middle, with one end turned up and the other down. This looks like Reflective design! I tried to post the picture, but it was too big. This pipe looks like it avoids the Restrictive design (common in stcok pipes), to acheive noise cancellation with minimal power loss.

Big Gun makes a Quiet Series pipe (Absorbtion design, like most aftermarket pipes) that claims to use a patented German packing material resulting in a 94dB pipe. Question is how was this measured (at what RPM) and how long the packing material will last. Advantage of the Reflective design is it's metal and will last, but this looks promising too.

Finally, White Bros E-Series pipes have a quiet core option, but when I saw it, it was clearly Restrictive design. They claim that the core reduces 5-6 dBs with no power compromise, but I'm a little skeptical. They also sell other quiet cores for common pipes.

I'll bet that the Euro bikes are already employing these designs and that's how they balance performance/noise.

If anyone has these pipes, please post measurements, if you can, and performance opinions.

Many have argued against quiet pipes that compromise power and I'll agree, when it comes to upgrading from a stock Restrictive design pipe. But, we don't have to upgrade to a loud (typical Absorbtion design) aftermarket pipe when there are Reflective and advanced Absorbtion (Big Gun) pipes available now.

I think the power difference between typical aftermarket Absorbtion design and newer Reflective/advanced Absorbtion design is very minimal and for those of us riding public land, certainly not worth the noisy consequences.

By buying smart, we'll be sending the right signal back to pipe makers who will advance Reflective/Absorbtion designs even further. This is something we can do, with little power compromise.

The Forum was kind enough to "Top" this post to support logging of sound measurements. All of you who acquired/have access to sound meters, please post measurements. If anyone buys quiet cores, before/after measurements and opinions would be really helpful to those considering that purchase

I bought the Intercomp (used by AMA) meter today and will start measuring a variety of bikes soon.

Thanks to all who help.


Posted by: mkuder---------------------

While employed at Purolator Products in the early 90’s, I was involved in the air box production drawings for the Dodge Viper. Chrysler engineers designed the housing and we detailed it for production. This was when they were working on the hardtop version with the hood scoop. They were having problems passing the EPA exhaust dB levels and didn’t want to restrict the flow to accomplish this. So their engineers modified the air box and from what I noticed as major changes were what I would consider to be acoustic chambers on each side, as it has dual plenums. I’m not sure if this would be applicable to our cause, but thought it was worth mentioning.


Posted by: scar tissue---------------------

Quote:
Originally posted by Okiewan
Excellent thread.
I must confess to being too loud last year, White Bro's R-4 ...
Pulled it today, stock pipe goes back on. I feel better.


Okie,

How much louder is the R4? I have a line on a good, slighly used one for my 250f for pennies on the dollar over new. But don't want to be totally obnoxious on trails.


Posted by: Brianc---------------------

Quote:
Almost all Harleys make an unbelievable amount of noise. These exhausts are intentionaly put on to increase and change the sound over a stock muffler. However, I haven't heard of any new laws being made to decrease their noise levels


Most Harley pipes are illegal in most states. Even in Az. ( a.k.a the wild west )
The loud pipes are illegal, as are loud obnoxious car stereos, the police choose not to enforce the laws.

The aftermarket exhaust manufacturers can make quiet system that produce more power, they choose to make louder exhausts, because louder sells better. The key to more power is gas flow. Noise is not directly related. Why can a V8 truck engine produce more power with less noise than a dirt bike? An exaggerated example would be to use a high performance car muffler on a dirt bike, NO noise, just lots of free flowing gasses. The technology to produce a quiet system is very simple, just need to convince FMF and others to start doing it. Anyone that wants to learn more should read 'The design and tuning of competion engines.' by Phillip H Smith. It is written for the road racing and Formula one communities, but the physics apply to dirt bikes as well.


Posted by: Brianc---------------------

Quote:
In an earlier post, I attached a link that simply explains exhaust designs. One possible solution to the "quiet vs. performance" trade-off seemed to be Reflective designs, common in auto mufflers. This link is helpful to understand that solution and the following discussion, so here it is again:

http://www.howstuffworks.com/framed...hausttheory.htm


While most of the info at that link is basic, it is only partially accurate. The science of gas flow is fairly simple to understand, and contrary to that writers opinion, header design, pipe sizing, and other variables are in fact easily calculated. The basic parameters need to be decided first. What RPM range, engine size, induction system, and volumetric efficiency are the starting points.

At the risk of sounding redundant, the aftermarket manufacturers can make quiet system that perform better, we as a consumer group, need to demand it.


Posted by: IBWFO---------------------

What you have stated is true, but it is cost prohibitve. Pipes would be heavier and much more expensive. That is the trade-off.

D


Posted by: NVR FNSH---------------------

Quote:
Originally posted by IBWFO
What you have stated is true, but it is cost prohibitve. Pipes would be heavier and much more expensive. That is the trade-off.

D


I have to disagree AND bring up the fact that KTM has done a respectable job in doing so, again. KTM may not be building the ulitmate exhaust on the RFS bikes but it certainly isn't too heavy or too expensive. IMO they've come up with a well balanced solution.

JamesP - I believe somebody posted their KTM was at 91-92dB.

Brian


Posted by: Kramer---------------------

if you can easily calculate the optimum geometry/construction for min. noise, weight, and max power you have likely made some invalid assumptions.

Or, you are incredibly gifted.

Computational Fluid Dynamics is the field that is best equipped to deal with these questions. Undergrad engineering students barely get their feet wet on the subject. Seems schools feel it's best left to grad, and post-grad work.

At any rate there aren't Pn'Play equations for it.


Posted by: Brianc---------------------

Quote:
Computational Fluid Dynamics is the field that is best equipped to deal with these questions.


That is a common misconception. Fluid dynamics and gas flow ARE NOT even close to being the same. You cannot compress liquids, you can compress gasses. Huge difference in flow dynamics.

With fluids, you deal with constants; pressure and flow rates (viscosities). Flow rate in directly affected by and proportional to pressure applied.

With intake gasses, you have ramcharging effects, with exhaust flow you have scavenging effects, these are simple principles, yet they are the most important to understand in the design of intake and exhaust systems.

As mentioned by another enlightend person, the aftermarket systems are grossly overpriced. Yet they are poorly designed. For $800.00 you can sell an efficient, mellow sounding system that does perform better than stock. For people not familiar with retail vs manufacturing, the true cost of production is typically 25 to30% of the retail price. So yes, they can make a lighter than stock system for $240 actual cost.

Right now, they want to sell us a $600 to $800 poor performing system that looks pretty.

Quote:
At any rate there aren't Pn'Play equations for it.


Actually there are numerous reference manuals that teach the physics and the math.


Posted by: James---------------------

Quote:
Originally posted by Brianc
The key to more power is gas flow. Noise is not directly related. Why can a V8 truck engine produce more power with less noise than a dirt bike? An exaggerated example would be to use a high performance car muffler on a dirt bike, NO noise, just lots of free flowing gasses.


It should be obvious why a V8 engine can produce more power with less noise. About 20 times the displacement will get you lots of power to pull a big muffler and lots of sound barrier. Put an auto muffler on a bike and see how it handles. Where is your back wheel going to go? The other thing is that the exhaust gasses usually travel at least 10 - 15 feet before it exits the pipe. If we are lucky, we get 4 feet on a bike. Makes for a lot more room to dampen the sound.


Posted by: mtngoat---------------------

Quote:
Originally posted by IBWFO
What you have stated is true, but it is cost prohibitve. Pipes would be heavier and much more expensive. That is the trade-off.

D


The February issue of Dirt Rider reviews the FMF PowerCore "Q". The pipe combines advanced Absorbtion material with "chambers" (Reflective design). It was tested on a XR400, DRZ400 & KTM 400 EXC. It produced significant power gains on the XR and DR; modest gains on the KTM (which has what many to be the best stock pipe). It is significantly lighter than the stock pipes (except for the KTM, which is also light). It registered under 93dB ( I'm not a frequent reader of Dirt Rider, but I figure they measure "SAE at idle"; anyone know?). Dirt Rider called it the best "woods" pipe they ever tested.

http://www.fmfracing.com/

Seems the pipe makers are responding with OPTIONS (Big Gun & White Bros have "quiet" models too, but FMF has the only Reflective/advanced Absorbtion pipe I've seen so far). It's now up to us to make a "sound" decision.

Next on our agenda should be exploring aftermarket "add-on" inserts (for all the existing pipes we don't want or don't have the money to replace) that attenuate sound with minimal power loss. More of these devices are coming out and measurements would help us make informed choices.

BTW, one of the obvious reasons for loud Harley pipes is the aesthetic draw of straight pipe looks, which don't offer the capacity for much sound attenuation. Most Harley owners don't want a "can" on their exhaust.


Posted by: mtngoat---------------------

Here's a cutaway view of the Q pipe


Posted by: mtngoat---------------------

Here's a link to a dyno run with the Q pipe on an XR650. Their site has runs for other bikes too.

http://www.fmfracing.com/01/dynocha...%20Q%20DYNO.jpg


Posted by: James---------------------

Surely the 93db reading is not at idle as it would be terribly loud at any pace. I base most of my comparisons on the XRs I have (sorry for always talking about outdated Japanese technology) which were measure at 5800 RPM and have 82 dbs which is right in the middle of the EPA 80-86 db standard for all bikes after 93 (I think). I think 5800 is a little over half of their RPM limit...my guess is 60% max.

You'd think 82 would be quiet but get on them any and you can hear them echoing across the pastures also. I would expect the next round of sound limits to land closer to the 82 than the current 94. I am still trying to find the correct document that clarifies EPA sound limits. Considering that we are going to an EPA emissions standard in 2006...it is only logical that the sound will be next.


Posted by: OldManIn---------------------

Quote:
That is a common misconception. Fluid dynamics and gas flow ARE NOT even close to being the same. You cannot compress liquids, you can compress gasses. Huge difference in flow dynamics


Actually CFD is applicable to both compressible and non-compressible fluids. A gas is a fluid and a liquid is a fluid. There are equations that deal with both. CFD techniques are used in aircraft engine (turbine) and airfoil design everyday. The problem is you don't have any motorcycle exhaust company paying an aerospace engineer $100K+ a year to do this analysis for them. So you get designs based solely on general theories with little empirical analysis to verify design effectiveness. The designers simply try things out and hook them up and measure on a dynometer. Make an alteration and try again. Then come up with some neat marketing strategy about some new method and make some money.


Posted by: Kramer---------------------

OldManIn, I agree completely. The other half of the problem, though is acoustic attenuation.

It's not hard to calculate resonant freq., or max flow, but there's alot more going on than that.

Brian, fluid flow is the same as gas flow. Those equations for incompressible liquid are, for the most part, simplified versions of eq's for compressible flows.

other, similar simplifications that are common are inviscid (versus viscous), irrotational (laminar) versus turbulent, constant pressure, constant volume, isentropic, adiabatic. Others that I'm forgetting...??

The big one that I see as a problem with applying the equations in this case is a variable Reynolds number. There may be a way but I guess that it would not have a neat, closed solution.

But, hey... in the end we're paying for pipes that probably aren't worth one tenth of their price.

I'd love to see a pipe with some serious R&D work.


Posted by: NVR FNSH---------------------

Quote:
Originally posted by Kramer
other, similar simplifications that are common are inviscid (versus viscous), irrotational (laminar) versus turbulent, constant pressure, constant volume, isentropic, adiabatic. Others that I'm forgetting...??


Are you trying to make my head explode? I've done my best to forget all those nasty words:scream:


Quote:
Originally posted by Kramer
I'd love to see a pipe with some serious R&D work.


You have - it's called OEM

I can watch open heart surgery on Discovery and read about it in a textbook but that does not mean I am capable of performing it.


JamesP - are you sure it was 82dB at 5800rpm @ 20 inches? That soundls awfully low for even a stock XR. Somewhere I have a nice little chart that shows how various noises/activities compare - jet engine blast ~115-120dB, office during business hours ~65-70dB, I think. I'll have to find it.

Brian

Brian


Posted by: James---------------------

Quote:
Originally posted by NVR FNSH
JamesP - are you sure it was 82dB at 5800rpm @ 20 inches? That soundls awfully low for even a stock XR. Somewhere I have a nice little chart that shows how various noises/activities compare - jet engine blast ~115-120dB, office during business hours ~65-70dB, I think. I'll have to find it.

Brian

Brian


That is what is on the sticker that honda put on the fender of both bikes. I imagine they are following EPA guidelines in determining their EPA sound level. I agree, that it sounds low compared to all of these other "quiet bikes". That is what has me so concerned. I keep hearing from various sources that the XRs are among the few that meet EPA sound guidelines. That is why I am so concerned when I see everyone so willing to give in on this issue as we all know how bad the XRs run stock and if we have to choke our KTMs, CRs, and WRs down to that level, they won't be so good anymore either. I know for a fact that I have not run across a stock bike that runs as quiet as the stock XRs do. I also know that my 400 with the 96 baffle is still more quiet than many stock bikes and when I rode with a KTM 520 exc guy a few months ago, I could hear his exhaust just as well or better than I could hear mine and hi swas stock also.

Next time you are at the honda dealer..take a peek at the rear fender..it'll be there.


Posted by: maicomotoman---------------------

Honda also claims that the XR400 weighs 257 pounds. Heavy, I know, but still about 7 pounds lighter than they actually weigh...My point is that I don't believe anything Honda, or any manufacturer claims. I agree that they are quiet, stock, but 82db seems too good to be true to me. Besides, how many people ride stock XRs? The stock Husky, by the way, is about as quiet as a stock xr(really) and runs really well. I am completly blown away by how quiet that bike is. The quietest big thumper I have ever heard.


Posted by: James---------------------

Quote:
Originally posted by maicomotoman
Honda also claims that the XR400 weighs 257 pounds. Heavy, I know, but still about 7 pounds lighter than they actually weigh...My point is that I don't believe anything Honda, or any manufacturer claims. I agree that they are quiet, stock, but 82db seems too good to be true to me. Besides, how many people ride stock XRs? The stock Husky, by the way, is about as quiet as a stock xr(really) and runs really well. I am completly blown away by how quiet that bike is. The quietest big thumper I have ever heard.


What does weight have to do with sound? Have you actually weighed one to know for sure it is 7 pounds heavier? Are you talking dry or wet?

How would you know if 82 was too good to be true, were you there when they tested it? And how do you measure "about as quiet"...is that a 10 db difference or 5? If it really isn't 82, then I'd hate to see how bad they had to be choked down to get 82.

No kidding nobody rides XRs stock...I have been saying that continuously. The point is, nobody rides them stock because to meet the EPA guidelines, it is pretty plugged up. These are the EPA guidelines that all bikes will eventually have to meet. These are the guidelines that the XRs supposedly meet now that most don't. Does your Husaberg have a sticker on it that says it meets federal noise emissions standards?

Problem is, we keep talking in circles with all of this speculation. That sticker on my fender is the closest thing I have seen to verifiable facts yet.


Posted by: maicomotoman---------------------

My point is that the sticker is not a verifiable fact any more than the claimed weight is. The sound levels obviously don't have any thing to do with the weight of the bike. I don't know what the sound level of my Husaberg is, nor do I have a sticker that tells me what it is. If it did have a sticker, I wouldn't tout it as fact until I verified it with a meter. I only have my ears to go by right now and here is what my ears heard from loudest to quietest of the bikes I've ridden with lately:"uncorked" yz426, "uncorked" xr400, stock wr250, stock Husaberg 400, stock gasgas300(2smoker),aftermarket pipe ktm200, aftermarket pipe kdx200,stock husky 410.I only said that the Husky is an astonishingly quiet bike, and that pipe and bike makers could learn a lot from it.


Posted by: James---------------------

Quote:
Originally posted by maicomotoman
My point is that the sticker is not a verifiable fact any more than the claimed weight is.

I only said that the Husky is an astonishingly quiet bike, and that pipe and bike makers could learn a lot from it.


A verifiable fact is one that you can verify. You can verify the weight by putting it on a scale. You can verify the sound by testing the same way they did. Both of those sound easily verifiable provided you have the scale, the sound equipment, and the test procedure. I notice you didn't put a "corked" XR400 on you list so it would be hard for you to dispute my 82 even by your "ear test" methods (which would be more difficult to verify).

Finally, if all you said was that the Husky was astonishingly quiet, then what was all of this:

Quote:
Originally posted by maicomotoman
Honda also claims that the XR400 weighs 257 pounds. Heavy, I know, but still about 7 pounds lighter than they actually weigh...My point is that I don't believe anything Honda, or any manufacturer claims. I agree that they are quiet, stock, but 82db seems too good to be true to me. Besides, how many people ride stock XRs?


I am as skeptical of those who quickly assume that it is easy to make bikes real quiet with power as you are of Honda's number claims.


Posted by: maicomotoman---------------------

Quote:
I notice you didn't put a "corked" XR400 on you list so it would be hard for you to dispute my 82 even by your "ear test" methods (which would be more difficult to verify).
I didn't include a "corked"xr400 because the only one I've seen is on the showroom floor of the Honda dealer. I'm not "disputing your 82". Nothing personal. Really. I don't even have any kind of problem with XRs other than the fact that they are heavy and slow, and that's not what I'm into. They CAN be made with better exaust systems. I didn't say it's easy, but it's possible and the Euro manufacturers have proven it because they have to. Soon the Japanese will have to also, and I'm sure they(some of the world's best engineers) will do it brilliantly...
Quote:
A verifiable fact is one that you can verify. You can verify the weight by putting it on a scale.
I know It's off subject but... I haven't weighed an XR personally, but Dirt Bike magazine weighed one: ready to run, no gas 264pounds.(claimed 257) I have personally weighed a Husaberg 400:ready to run, no gas, handguards, skidplate 250 pounds(claimed 242) I think that all manufacturers "stretch" the truth on these things...
I totally agree with you that it is all speculation until we get some actual metered numbers, and my estimations are completly subjective. These are just my unbiased observations.
Oh yea. The Husky that I keep raving about(you people must think that I'm some kind of euro-bike salesman)(I'm not...) is a 2000 model with two silencers. I think it's the only year they did it that way(?) And, no, I don't know why. Two- into-one-into-two. Pretty wierd, but it works...
Rock on


Posted by: NVR FNSH---------------------

JamesP - does the sticker say what test spec was used? My guess is it's a 'ride by' spec not the test that is being used in National Forests. I think somebody earlier listed the spec number - it's the 20"/45 deg/half red line test. Notice the mic is positioned only 20" away from the end of the exhaust. My wife will tell you that I'm louder than 82dB at 20"

Brian


Posted by: James---------------------

Ready to run, no gas would include about 2 qts of oil and brake fluid. 257 is the dry weight. That probably explains the difference.

I am not particularly defending the XR, I know it is "slow" and heavy. It is perfect for nasty rocky trail riding...and doing some casual doubles at the track. Prefer the CR by far, but it is usally apart for maintenance. I use it as an example of a bike that comes stock within EPA guidelines, runs fairly crappy stock, runs GREAT unplugged and therefore is a good example of what some exhaust will do for you on top of being a good example (in stock form) of what we can all be stuck riding if the ECOs have their way.

I am going to look into the KTMs again as a result of this thread.


Posted by: James---------------------

Will look at the sticker and see if I can find a reference to a test procedure. Still, 93 at idle sounds loud even at 20" and 45 deg. Matter of fact, at idle, we don't have to put any effort into talking louder than the stock pipe on the XRs and I think normal talking is in the 70 db range.


Posted by: NVR FNSH---------------------

JamesP,
My '99 WR400 was 95dB per the 20"/45 deg test - NOT at idle. More like 5500-6000rpm ( 1/2 of redline). At idle it's easy to hold a conversation next to the bike - not sure what the actual dB level at idle is.

Brian


Posted by: vegli---------------------

Hi Guys,

Great thread and "debate".

As to the statement that most bikes can not pass the new requirements, all I can say is that I ride most of the CCC events in Michigan (including the 6 days of Michigan) and we all have to pass the 94db test or we can not ride.

At the six days my ktm 200 tested at 92 db and my gasgas 200 at 91.5 db. This is by the EPA SAE J1287, June 86, 20” Sound Emissions Test Procedure.

You can say but those are 2 strokes, but the quietes bike there I think was WR250F that tested at like 97.5db I think.

Now that is very quiet.

I have after market pipes and sparkarestors on both of the bikes.

By working with the DNR (they do all the testing and some also ride) and working with them on trail mataince and development we have hundreds of miles of trails and dual sport avaliable in both the Upper and Lower Peninsulas. (over 2000 miles of marked trails in both I think)

On the six day ride I rode the trail option and put in more than 720 miles.

I say say all this to make the point that if we were all going around saying that "its my right to be loud" and "run over the warden" we would not have 34 years of good relations with "the poweres that be" and thousands of miles of trails (many payed for out of DNR monies).

If we are not the ones carring the "olive" branch, there most likely will not be an end to the war.

Here is a link aboout the CCC

http://www.cycleconservationclub.org/ccc.html

I now that there are many good clubs doing great things, this is just another one I think, but they are doing it this within the system and not without it.

These are my 2 cent .

Vern


Posted by: maicomotoman---------------------

Quote:
I say say all this to make the point that if we were all going around saying that "its my right to be loud" and "run over the warden" we would not have 34 years of good relations with "the poweres that be" and thousands of miles of trails (many payed for out of DNR monies).If we are not the ones carring the "olive" branch, there most likely will not be an end to the war
Amen brother. Thank you.
720 miles I hope you are not using the stock KTM seat foam...


Posted by: vegli---------------------

maicomotoman

No I do not have a stock ktm seat foam or gasgas either... :^)

I raced a Maico back in 1978, a 400 ....

Thinking of trying to find a 81 490 and doing a little vintage racing.

Also wantng a new ktm 400exc, I want the "button"..

Vern


Posted by: maicomotoman---------------------

Vern, I have two '80 Maicos. A 250 and a 450. Good luck finding that 490, they are getting expensive...vintage racing is a blast, I heartily recommend it. I also highly recommend the e-start thumper. I have a new Husaberg, and can hardly contain myself. People think I have stock in the company The ktm is nice, but you should check out the 'berg before you commit. Happy motoring


Posted by: geremacheks---------------------

Here's my late, 50 cents worth:

Urban sprawl will hurt our sport badly in the end. "No you can't keep that riding area with all those stinking and noisy motors running all weekend long. Did I mention the dust? It doesn't matter if your track has been there 20 years and I just finished building my home in the woods next to you. I'll complain. You'll be out."

I agree, it not just about noise. All my life I've been on the wrong side of the recreation quotient. As a kid I ran a trapline and hunted every day--even before school in the morning. Later I liked the shooting sports--pistol, rifle, and shooting skeet. These have all become socially and politically incorrect by somebody else's standards. Do you even know anybody that traps today? Hunting has become a rich man's sport. Try to find a good hunting spot that isn't posted. The shooting ranges are closing--too close to new populations that have moved in. Even fishing has changed. It's somewhat socially acceptable to fly fish as long as you catch and release. Do not fish with worms and do not kill fish to eat. Again, somebody's accepted standards.

Sorry guys and girls, your choice of dirt bikes and off-road riding recreation does not appear to be a civilized, accepted sport. Don't plan on being accepted by large numbers of the population. They look at us more like targets, and have better plans for the land that we want to use. How about more bicycling, hiking, bird and wildlife watching, tennis, swimming, golfing...and that final 10 acres that's left? "We'll make that into a curling rink."

"You want to ride dirt? Do it on a video screen." It's no wonder I'm paranoid when I ride in the woods.

Tell me: when was the last time you got one of those vacation-retirement brouchures touting "we have tennis, golf, swimming...and heck yeah, MX, hillclimbs, and hare scrambles too."

No, it's not about noise. If it were, we'd be fighting back. Why should we tolerate jet engines, miles above our homes, drowning out the kids TV shows? What rights are far-away helicopter pilots practicing when they shake your windows with outright noise and turbulence? And the little single engine planes joy riding on the weekends, their loud exhausts reverberating off the ground, and they are not even close!

Why aren't we complaining? At least in retalitation. Our dirt bikes were never that loud.

I've been subtlely polite with my bikes. The EXC has the stock KTM muffler. The KLX before it had the well know limiting stock muffler with the dime sized exhaust outlet. No plugs pulled.

But guess what? It doesn't really matter in the long run. Too many other things are working against us.

The phrase under my signature is meant to be funny, but in time, some of us more desperate riders will make it truth, despite of the trouble we might be digging ourselves into. We'll justify it and rationalize it somehow.

Sure, quiet the bikes for now. But never believe it's the answer. I think Harleys will continue to make noise. Why? Their sport has become a civilized, accepted recreation, with a huge population of support. Somehow, they have earned the right. We haven't.

And I can't offer any win-win solutions. My other recreations have failed, and I'm afraid this will too. I know it's selfish, but mostly I promote enjoying the sport while you can. And make it better somehow. And I hope our kids can enjoy it in the future. But hope is a weak word we can't rely on.

Now that I have myself irritated, I should react to all my statements, and do something about it. But it's close to midnight, so I think I'll just go "tee off."


Posted by: maicomotoman---------------------

Quote:
It's finally midnight, on a moonlit, summer evening, and I can't even begin to describe the soft, nuances of orange and silver light coming from my KTM, as it idles cleanly, deep in the sand trap, at the edge of the 17th hole.
A man after my own heart.
In the future all golf courses will be reserved for...moto! A perfect world....


Posted by: geremacheks---------------------

Macio Man: They sure aren't reserved at present.

Anybody got any time to help me untangle some guy's Big Bertha from my chain and spokes?


Posted by: Brianc---------------------

Quote:
The problem is you don't have any motorcycle exhaust company paying an aerospace engineer $100K+ a year to do this analysis for them.


You don't need an over priced engineer to do the math for you. We are talking about 1970's technology. The principles of ramcharging ( on the intake side ) and scavanging ( in the exhaust side ) isn't complicated. Especially in a single cylinder design.
The ramcharging effect is impossible to achieve with fluids, that is why you cannot apply fluid technology to gas flow.
Ramcharging occurs in every internal combustion engine, without it the engine could not run above idle, because the piston could not draw in the fuel mixture in the fraction of a second that the intake valve is open. The engine relies on ramcharging to force the mixture in the cylinder.Exhaust scavenging is also not duplicated by fluid flow, yet its effect on an engines performance is well known by every 2 stroke owner who has tried a different pipe. Even if they did not know what the pipe did, they felt what it did. ( Wasn't it Honda that tried a turbine wheel in the pipe to assist the exhaust gasses?)

Phillip H Smith wrote 'The Design and Tuning of Competition Engines' He explains the principles and provides the formulas. The research was done by F1 teams and is proven to be accurate.

Look at the 'new' square design from FMF. That is a copy from Maramount's ' Z flow ' design from the late 1970s.

The only point I wanted to make in my original post in this thread is that we are being overcharged for an under designed, poor performing product.


Posted by: Brianc---------------------

Get Involved!
Americans for Responsible Recreational Access (ARRA) has always stood for responsible and open use of public lands and waterways. ARRA believes that there are better approaches to the management of public lands than just denying access.

On February 27, H.R. 3808 - Consistent Public Land Laws Enforcement Act of 2002, was introduced in the House of Representatives by Rep. Scott McInnis of Colorado. Solutions that ARRA has been advocating are included in this legislation - enhanced enforcement tools for the three Federal agencies with the most responsibility for managing our public lands and increased punishment for those who break the law.

Fighting for access to America‚s public lands is a tough battle. The "Do Not Enter" groups have a long head start on us. However, with reasonable, responsible solutions, we can prevail, but only if we Act Now!

Click the NEXT button to send a fax Today! Ask your Member of Congress to co-sponsor H.R. 3808. Click here if you would like to read more about this legislation <http://responsiblerecreation.policy.net/legupdate/> .

If you would like to alert others to this issue please click on Spread the Word in the Action Center <http://responsiblerecreation.policy.net/grassroots/> to send 5 e-postcards and help even more.

ARRA supports H.R. 3808 as an important step in bringing some balance to the debate and we hope you agree. ARRA hopes that similar legislation will be soon introduced in the Senate. When that happens, we will let you know.

If you are unable to see the above links, please visit http://www.responsiblerecreation.com to take action.


Contact Us <http://responsiblerecreation.policy.net/contact.vtml>


Posted by: mtngoat---------------------

Over the weekend, I made two measurements, more to come.

Anyone think of other "bike profile" data that's relevant, please post.

95 KLX 250/340 (Scar Tissue's old bike)
Procircuit pipe (est. 6 years old, never re-packed?)
Stroker header pipe
Stroker bore & stroke
Idle: 82dB
WagHo*: 88dB

2001 XR650
Hop-up kit
Whte Bros E-Series (1 year old)
12 discs, no quiet insert
Idle: 88dB
WagHo*: 103dB

Both measurements above made at 7000' (any of you "propeller heads" know if reduced air density makes a significant difference?)

I called FMF and asked what RPMs for their advertised measurements. They responded; @ 3000rpm. Also, on their site, they recommend pulling the clutch in neutral for a quieter measurement. I'll test that this weekend.

I've e-mailed Bill Dart to determine how we can expect to be tested on most public land (e.g. actual rpm or quarter/half throtlle or ?). I'll post his response.

*WagHo=wild arse guess of half throttle


Posted by: geremacheks---------------------

That's something I always wanted to be.....a propeller head. Probably would flunk the sound test, though.

Maybe it's time for the spokesmen of some of the pipe manufacturers to step up and defend their products and the R&D that has gone into them. I'd like to hear their side of it, not just what's going on here.

Some companies out there must be interested in what the "market" is thinking and saying.

Second thought: maybe you should remain quiet. Would anybody believe you anyway?

About manufacturer's bike weights: Aren't these dry shipping weights, and if so, would they not be near accurate for shipping purposes. The shipping weight is usually stated on the MSO, or papers you receive with a new bike.


Posted by: scar tissue---------------------

Quote:
Originally posted by mtngoat
Over the weekend, I made two measurements, more to come.

Anyone think of other "bike profile" data that's relevant, please post.

95 KLX 250/340 (Scar Tissue's old bike)
Procircuit pipe (est. 6 years old, never re-packed?)
Stroker header pipe
Stroker bore & stroke
Idle: 82dB
WagHo*: 88dB




I told you she was quiet How'd you like your first ride?I know this is a different forum so you can email me if you 'd like.


Also I was glad to here the E series was as quiet as it was


Posted by: NVR FNSH---------------------

Quote:
Originally posted by Brianc


You don't need an over priced engineer to do the math for you. We are talking about 1970's technology. The principles of ramcharging ( on the intake side ) and scavanging ( in the exhaust side ) isn't complicated. Especially in a single cylinder design.
The ramcharging effect is impossible to achieve with fluids, that is why you cannot apply fluid technology to gas flow.
Ramcharging occurs in every internal combustion engine, without it the engine could not run above idle, because the piston could not draw in the fuel mixture in the fraction of a second that the intake valve is open. The engine relies on ramcharging to force the mixture in the cylinder.Exhaust scavenging is also not duplicated by fluid flow, yet its effect on an engines performance is well known by every 2 stroke owner who has tried a different pipe. Even if they did not know what the pipe did, they felt what it did. ( Wasn't it Honda that tried a turbine wheel in the pipe to assist the exhaust gasses?)

Phillip H Smith wrote 'The Design and Tuning of Competition Engines' He explains the principles and provides the formulas. The research was done by F1 teams and is proven to be accurate.

Look at the 'new' square design from FMF. That is a copy from Maramount's ' Z flow ' design from the late 1970s.

The only point I wanted to make in my original post in this thread is that we are being overcharged for an under designed, poor performing product.


A friend of mine designed/built a pipe for his RM250 for his Mechanical Engineering Senior Design project at Cal Poly. As an engineering student (with supervision/access to PHd professors) you would think he would have a better shot at understanding/succeeding in improving upon the 'compromised' stock Suzuki pipe than John Q. Public just reading the formulas out of a book. In a nutshell, the pipe didn't work very well. He didn't try to package it for the bike - it was a dyno test pipe only (it stuck straight out the side). I don't remember the particulars so I've asked him to fill me in.

My point is that it's not just a matter of applying the formulas found in a book - you've got to know how to apply them and what they actually mean. I don't believe most of the aftermarket exhaust companies have this expertise and that is why they offer the pipes/silencers they do.

I was looking at the Feb '02 Dirt Rider CRF450 exhaust article last night and was surprised that most of the pipes were less than 1 horsepower different from the stock pipe at 5000rpm. The big improvements were way down low at ~2500 rpm. I was extremely disappointed that even Big Gun's quiet core was 101dB.

Brian


Posted by: James---------------------

Quote:
Originally posted by NVR FNSH
JamesP,
My '99 WR400 was 95dB per the 20"/45 deg test - NOT at idle. More like 5500-6000rpm ( 1/2 of redline). At idle it's easy to hold a conversation next to the bike - not sure what the actual dB level at idle is.

Brian


The sticker on my bikes does not give any reference to the test procedure mentioned. I did make a mistrake, the 650l is 80 dbs @ 3800 rpm, the 400 is 82dbs @5500. In my opinion, the XR400 is more quiet than the 650l in stock form.

SOmeone else made the comment about meeting the 94db standard. That is all good and well but that is the AMA standard and not the EPA. EPA is 80-86dbs for bike made after 82 as stated in this article under "other regulated sources of noise"

http://cnie.org/NLE/CRSreports/Risk/rsk-52.cfm

The point I am trying to make is that many localities are moving towards a completely stock exhaust requirment and bikes have to meet the EPA sound emmission requirement in these places currently (I think Albuquerque NM is one of them). I expect that this movement will catch on and as the pollutant emmissions requirements very similar to street bikes will apply to dirt bikes in 2006, expect the noise requirements to be not far behind. SO you may pass the AMAs 100 or 94 db test now, but that is still a long way from 82. SO we should strongly oppose any additional legislation while we do what we can to be quiet rather than assuming we can be quiet enough for them to leave us alone. There is still time to fight this 2006 emmissions issue also and I can think of many, many more serious sources of pollution than our two stroke motorcycles.


Posted by: 7075T6---------------------

Last year when I was riding a KTM EXC 520 I tried some different pipes.Among them SX 520 original and Pro Circuit T4. You dont spend so much in the upper revs with the 520 but I think itīs very important to have a smooth bottom end.The T4 is all noise and lost low end.The stealth EXC 520
is by far the best pipe for allround use.Very low noise and good power everywhere.
It seems to be a big problem to find such a pipe for my CRF 450! Maybe a modified KTM-pipe is the final solution.


Posted by: mainer---------------------

Good thread.

Some misconceptions and clarifications:

Snowmobiles are much quieter than in the past because the manufacturers are smarter. Snowmobile make more power than ever, and most aftermarket pipes add little power. Snowmobiles are still too loud for some. Snowmobiles run in the winter when windows are closed. People who pipe sleds are idiots and make life harder for us who keep the trails open and seek land owner permission. Dirtbikers aren't near as organized as sledders. We dirtbikers can't compare our sport to sledding.

Harleys are loud, Harleys are getting louder. Harleys travel on public roads and don't require private land owner permission. Harley riders won't lose the right to ride, they'll just get tickets. Police are too busy to write harley riders tickets for noise.

Thumpers are loud. Piped thumpers are very loud. Thumpers ride on private land, at least in maine. Thumpers ride when temps are warmer and windows are open. If we don't police ourselves it will get done for us. This isn't an us vrs. the greenies, this is us vrs. us. Your an idiot if you think ignoring this issue will make it go away. We compromise or lose.

mainer (sledder, dirtbiker and harley rider)


Posted by: mtngoat---------------------

Latest dB check:

Scar's new WR250F (very nice bike with great suspension and wide power!!)
E-Series, 12 Discs
Idle: 96dB (Idle was set high so the reading's high, I'm guessing 94dB at idle)
Half Throttle: 102dB



White Bros claims their new quiet insert (new one looks like a perforated ball, instead of the old perforated pipe) reduces 5-6dBs with no power compromise. Anyone tries this, please post.


Posted by: dirt bike dave---------------------

Regarding the manufacturer's stickers with db readings in the 80+- range, I believe those are conducted 50 feet from the bike. The 94+ db AMA measurement is conducted like 20 inches away.


Posted by: RetSenior---------------------

Was at Stonyford riding yesterday and when we got back to camp the Rangers were there doing voluntary sound checks. They used a Quest model 1400 sound level meter with a little black plastic Briggs & Stratton RPM gismo. Tested a 2001 KTM 520 EXC with a Pro Circuit T-4 exhaust with a 2" end cap at 3500 rpm's per the Motorcycle Industry Council booklet that only had bikes listed up to the 2000 model year and the 520 was not listed but the 400 was so he used that rating of 3500 rpm's. The result was 102dB's with 101dB's being the max allowable. He did my bike next which is a 2001 KTM 520 EXC with stock exhaust. The result was 92dB's at 3500 rpm's. The Ranger got a 91dB result with my Extech model 407750 sound level meter. I still have yet to do a repack on my exhaust with aprx. 2500 miles on it. I did not notice the other 520 out perform my bike in any way. We are equal rider with different riding styles. He jumps all the water bars where I wheelie over most of them. With the type of riding we do in the forest I can't figure where the T-4 makes an improvement for the bike except for a 5 pound lose of weight.

ps. Here's the RPM gismo Briggs & Stratton sells. My local lawn mower shop had it. http://www.treysit.com/TREYSIT_Pres...-_about_us.html


Posted by: NVR FNSH---------------------

Quote:
Originally posted by RetSenior
With the type of riding we do in the forest I can't figure where the T-4 makes an improvement for the bike except for a 5 pound lose of weight.


5lbs? That can't be right. The KTM can is long but 5lbs sounds like PC marketing hype to me.....

I rode the Wild Piglet with Projectboy - he has a YZ426 w/WB E-series (I think), I have a WR400 witht the stock exhaust/Thumper Racing insert - there really wasn't any place he could outrun me and I weigh quite a bit more than he does.

Brian


Posted by: RetSenior---------------------

Looking back at some post I believe there was a error in dB sound doubling. I had always thought 3dB's was a doubling and 10dB's being 10 times. http://www.glenbrook.k12.il.us/gbss...und/u11l2b.html

As posted by Steve on TT and thanks:
The formula for calculating the Intensity of sound in Watts per square meter is as follows.
Li=10log(I/Io) where Li=deicbels sound. I=intensity of sound in Watts/m2. Io=sound intensity at 0 decibels which is the constant 1x10 to the neg 12th power. Using this formula to calculate relative sounds you come up with the following:
Decibel increase Increase in Intensity
1 Decibel 1.2589
2 Decibels 1.5849
3 Decibels 1.9953
4 Decibels 2.5119
5 Decibels 3.1623
6 Decibels 3.9811
7 Decibels 5.0119
8 Decibels 6.3096
9 Decibels 7.9433
10 Decibels 10.0000

So, an increase in 10 decibels equals an increase in intensity of sound of 10 times!. A 3 decibel increase equals a doubling of sound. Even one decibel increase causes a 25 percent gain in sound intensity.

Please check and correct if wrong, Thanks

ps. Brian that bike that was 111 dB's would be 100 time more powerfull than my KTM.

pss. That Treysit tach I bought I tested at work on our motors with set RPM's and it was dead on or damn close.


Posted by: uoof1---------------------

I agree 100%. I love all bikes, and own a WR426. I wish it were more quiet. I just got back from Bike Week, and after being stuck in traffic for hour after hour with out of tune Harleys with straight pipes, I am more aware of the problem. Every manufacturer can make quiet exhausts, I hope they will soon. Kevin


Posted by: mtngoat---------------------

Two of our local SoCal members have purchased new WRs and both will have the White Bros. E-Series pipe. One has agreed to buy the new Quiet Core insert, which appears to be updated from the previous "perforated pipe" deisgn to more of "spherical" design.

This should get us an end user "sanity check" on the advertised claim that it will reduce "5-6 dBs without sacrificing performance".

Hope to post results soon.


Posted by: mtngoat---------------------

Ret, I've looked for that RPM meter and haven't found it. Did you get a price? Thanks and also thanks for all the informative posting.


Posted by: woodsripper---------------------

4-strokes seem louder than 2-strokes at the same dB due to the frequency of the sound. Low frequency sound (4-stokes) has a longer wavelength and is not easily attenuated by trees, ground, etc. I have the stock exhaust on my 400 EXC and I think it is loud until I ride next to a YZF with an aftermarket pipe. My KTM is very quiet in comparison.


Posted by: Rick Currah---------------------

Riders,
As President of the Ontario Federation Of Trail Riders (Canada), I have dealt first hand with the problem of noise and those who support or oppose it.
What everyone in North America needs to do is ask the riders of Massachusetts or New York what they think. I'm a Canadian but I believe that riding is oulawed in Mass. and on the run in N.Y. I'm sure the riders would gladly suffer with a stuffed-up pipe, just to ride the countryside of their state.
The riders of Michigan have united under the CCC to deal with the problems facing off road motorcyclists. Their example of mutual respect with other forest users and Zero Tolerance toward renegade riders, are to be commended. The CCC has a proven track record with the state forestry authorities. They train youngsters properly, upon entering the sport and promote the sport as a Family Venue. Michigan's CCC are the envy of the continent, and rightly so.
I would suggest the riders carrying a chip on their shoulder, attend a CCC event and partake of the sport as it should be done.
There is room for cool heads and comprimise. If it is a fight you are looking for, keep it up. You will find it and you will lose. The sad thing about this divide in tactics is, you will run all the rest off, with you.
It is sad to see us fight amongst ourselves. The "Greenies" must be killing themseves with laughter.
Rick Currah


Posted by: mtngoat---------------------

Took a little longer than expected and I haven't re-tested the non-quiet core WR-250 with the vibration tachometer, but here's prelim results:

02 WR-250
E-Series 8 discs w/Quiet Core
@3500 RPM
98 dB

Then, we installed 4 more discs (which purportedly lessens back pressure resulting in more top end and noise) and we got a 96 dB reading! One possible testing error is the vibration tach, but the shop that sold it seemed convinced it's very accurate. Unless the RPMs were off, I'm at a loss to explain why this happened.

The owner didn't experience any power loss (compared to a ride without the quiet core), but did feel a bobble off throttle. This may be caused by high altitude riding that day and a mis-adjusted idle circuit.

I recall the other WR-250 came in around 102 dB with a wild guess at 3500 RPM, which syncs with the Bill Dart article.

White Bros' claim of a 5-6 dB drop with no compromise to power seems to hold water...so far.

I hope to get both bikes at the same time soon.


Posted by: RetSenior---------------------

mtngoat, I know the 426's get tested at 4500 RPM's. Is the 250's a lower rev'er. It's not in my MIC book but will be in the Revisd version do out soon.


Posted by: JWW---------------------

Quote:
Originally posted by mtngoat
02 WR-250
E-Series 8 discs w/Quiet Core
@3500 RPM
98 dB

Then, we installed 4 more discs (which purportedly lessens back pressure resulting in more top end and noise) and we got a 96 dB reading!

.


Bikes a 01

As mentioned above I didnt notice any power loss. I would add that even if I lost a little power it would be worth the trade off. I never realized that 4-5 db difference would make such a big difference.

Before I get hit with the why did you switch from stock to the E-Series........Power increase is nice but the main reason is the stock pipe isnt forestry approved.


Posted by: maicomotoman---------------------

Quote:
Power increase is nice but the main reason is the stock pipe isnt forestry approved.
wtf? Isn't the WR supposed to be a woods bike? Methinks Yamaha has some work to do...


Posted by: JWW---------------------

Maico---- I should revise that statement.

The muffler is not stamped usfs approved.

For all I know it has a spark arrestor but if the ranger cant see a stamp the bike is not legal. Could be because the bike is a canadian model


Posted by: mtngoat---------------------

Ret, the WR-250 is a high rev'r. The one missing component from my "test gear" is a manual that specifies RPM. Can you give me the source for the "MIC" book?

We ran the RPMs on the WR250 over 3500 and the dBs stayed under 100. I'll try it again at a measured 4500 when I get a chance.

Thanks


Posted by: RetSenior---------------------

mtngoat, just give http://www.mic.org/_index.html# a call and they will mail you one. Here's the contact:

Mr. Will Hawes
Director, Aftermarket Programs
2 Jenner Street, Suite 150
Irvine, California 92718
Phone: (949) 727-4211 Ext. 3046
Fax: (949) 727-3313
E-mail: whawes@mic.org

ps. I left a message on his answering machine and he called me back a little later for my address and I had the book in a couple of days.

That's strange that the stock Yamaha WR does not have a Forest Approved Exhaust. We have a lot of forest riding in NorCal.


Posted by: mtngoat---------------------

Thanks again Ret!

Just spoke with Will (Motorcycle Industry Council). He's mailing me 6 copies to distribute to others who want to sound test. Will was interested in our thread and said he'd log on and register to post his own sound test results on a 426 he rides on track and in the woods.


Posted by: cjm---------------------

i am in the performance boat business.five years ago we were told that noise laws were going to be enforced on powerboats.we laughed at the time.now,when we show up at the state park boat launch's,the n.y.state park police are waiting for us with db meters.if you are louder than the limit,they wont even let you take it off the trailer.if the noise bothers just a few of the right people with the right friends they can put a hurting on your hobbies.i would rather keep my machines legal and quiet.it's nice to pass the wood's police and have them wave to you instead of flaging you down to give you a handfull of tickets


Posted by: yz426xx---------------------

This really bothers me, I have just purchased a 01 426f for my first REAL off roader. The bike really has awesome power and it's just a blast to ride. Now, from what I have just read, I have a high chance of being labeled as "another a-hole on a loud four stroke." When you spend a chunk of money like that and immediately start having to spend more money to make other poeple happy and get off your back, where has the fun gone? I feel if it came that way, there was a reason for it. Sure if you have to have an aftermarket pipe, by all means, go with the quieter one of course. I will not spend money on a bike and turn around to spend even more on an exhaust system becuase someone feels the stock set up is not quiet enough. I started this hobby becuase my hot rods were "too loud, too fast, and corrupted the local youth." Now it seems like it's the same book, just different chapter.


Posted by: Rodzilla---------------------

See 426,

The other forest users are saying the same thing. Where has the fun gone?

Campers, hikers, equestrians et al. Are saying they get into the woods for peace and quiet, this is their "fun". Just as riding is our fun.

I am an avid rider, but you know when I'm in the woods and NOT RIDEING I kinda like it quiet too. I'm not knocking your statement other than we have to see both sides and do what we can to work together. If we don't we WILL LOSE.

RZ


Posted by: yz426xx---------------------

Around the Dallas area, there are many places to ride. Places that are set aside and made soley for riding. However, I remember when The Motorplex was built in Ennis. It as pretty secluded and a good ways away from any sort of population. Now, poeple want to shut it down because it is way too loud and it gets really crowded on event weekends. Poeple that moved in AFTER the place was built, poeple that knew the place was there when they moved in. I'm afraid this is what's going to happen here. I only ride at designated areas or my mothers farm which is in BFE. I too enjoy the quiet and peacefulness of my nature areas, but, I don't ride there. I do think we should respect other poeples feelings, privacy, or whatever, but like you said, ours should be respected too. My bike came a certain way, until it wears out, it will stay that way.


Posted by: Rodzilla---------------------

I understand completely.

It's like the yo-yos that move in next to the airport (because the homes are cheaper) then complain about the noise! Well DUH!

We too have a great track that is miles from nowhere. Last year they put a golf corse in two miles from the track. What comes with golf? people with the money to play, what comes with $$? Clout. I'm sure once the homes start popping up, the tracks days are numbered.

Also I don't blame you for not wanting to put $$ down on a pipe on a new bike, I don't want to either (although my KTM is very quiet) I do Blame Yamaha. The pipe on the YZ are obnoxiously loud!


Posted by: scandi---------------------

Why is it we are always made out to be the bad recreationalists? In California, we are lucky to find someplace to ride, and when we do it is we have to drive 1-2 hours. Who are we bothering in these remote areas? I understand the restrictions, however I become very frustrated over having to give in and not get anything in return. If they are going to enforce the laws in the middle of nowhere, how about enforcing the noise laws in town?


Posted by: mtngoat---------------------

For those still following this thread and interested in measurements, here's the RPM measurement level for some common thumpers:

Yamaha YZ/WR 400/426 (98-00) 4500
Honda XR400 (96-00) 3750
Honda XR650R (00) 3250
Honda XR250R (98-00) 4000
Kawasaki KLX300 (97-00) 3900
Suzuki DR400E (00) 4000

This came from the Motorcycle Industry Council "Test Manual", which is revised for 2001, although many thumpers are not listed. If the RPMs are not listed, the manual suggests a formula based on engine stroke, which approaches half of max RPM.

To summarize dB maximums, that I know of: for CA public lands, the max dB is 101; for AMA it's 99 and the manual recommends 96 be adopted in the absence of other regs, with a 1.5dB tolerance.

It looks like this Test Manual could be widely used for noise measurement. I have extra copies. If anyone wants one, send me a PM.


Posted by: kdxtaz---------------------

Although noise is an issue and we all should show our respect, we need to see the master plan of the xtreme greens. They actually worship the earth and most believe that if they live a "good life" they will be reincarnated into the animal of choice.They want to gobble up as much land as possible for their "future", and the 2-stroke & sound issues are just two more bricks in the "wall" that they're building. They are decieving the public with mislleading accusations of us and just about anyone else who wants to enjoy our open spaces, seeking ultimately to cram the people into the cities and ban them from wilderness. To them there is no more value on your human life than that of a common tree. It is like a religion to them, & they will stop at nothing to accomplish their goals. They must be opposed and stopped. Please go to this site www.wildlandsprojectrevealed.org and read the "slide show".
Thank You- 'Taz'


Posted by: Jh85---------------------

Posted by Rick Currah
Quote:
I'm a Canadian but I believe that riding is oulawed in Mass.

Not yet :D


Posted by: One Dollar---------------------

I didn't have time to read all the replies so excuse me if this was said..

I have the FMF Q muffler on my KLx and it is quieter than the stock one with the plug removed and does not limit performance. I recently passed a sound test on a dual sport ride, it came in at 92db.

The sole reason I got it was for the approved spark arrestor & sound quieting and it has done well. I repack as needed and agree that we all need to be quiet or we will lose land to ride on.


Posted by: donfitz69---------------------

Here's my 2 cents.
It doesn't matter how quite we are they are still going to want to keep us from riding. Look at NY state. There are almost NO places that are open to riding and there are plenty of state parks I go to that don't even allow mountain bikes. What harm is a mountain bike going to cause as long as its used on marked trails? NONE!!!!. Look at the friggin Sierra Club all they care about is closing off land so the only people who can use it are Hikers. Well why should land be closed off for only one type of use. THAT F'ING SUCKS. Mountain bikes make no noise and are still banned in most of the closure that were enacted during *******s term as president. Second I own my own land and ride on my own land, i'm going to use what ever F'ing pipe I want and if you don't like it go F yourself. I've had one person who was hiking on my property and complained that my bike was too loud. I told him that the exhaust was stock and that if he doesn't like it to get the F off my property and don't come back. Also for you aholes that have a problem with street bikes that have pipes that are too loud most people I know that have street bikes want a loud pipe not so people will notice then for the hell of it but so people will no they are coming and won't be oblivious to them.

Now on public land I agree most dirt bikes are too loud and I also agree that we shouldn't meet halfway for anything. Halfway is halfway to nothing which is where the greens want us.

If you don't like it go F yourself.


Posted by: donfitz69---------------------

why is the word ******* marked out with ********. The last time I looked ******* wasn't a curse word.


Posted by: donfitz69---------------------

why is c l in t o n a bad word???

This board is F'ed up


Posted by: maicomotoman---------------------

Congratulations donfitz69. You are part of the problem.
Quote:
Also for you aholes that have a problem with street bikes that have pipes that are too loud most people I know that have street bikes want a loud pipe not so people will notice then for the hell of it but so people will no they are coming and won't be oblivious to them.

This is the A#1 lamest argument I have heard. Maybe all of the Yugo drivers should go yank their mufflers off too? So they will be noticed more? Come on. The reason people like to run loud pipes is so they will be noticed, but it's more of a "hey, look at me on my cool hog" "it must be more powerful because it's really LOUD" Stupid.
The main reason "the greens" want to ban mountain bikes and dirt bikes is because their tracks speed erosion. It is also held by some "experts" that mountain bikes are more destructive than motorcycles because they exert more pressure per square inch. This leaves a deeper, narrower imprint which accelerates erosion. The motorcycle tread spreads its weight out more leaving a wider, but more shallow, imprint. I didn't make this up. I read it somewhere. It's been a long time ago so, no, I don't remember where I read it. Noisy bikes turn people away from our cause and our desire to keep our riding areas. I know of plenty of motocross tracks built on private land that have been shut down by adjacent landowners. Because of noise. When you are noisy on your land you are probably being noisy on your neighbor's land at the same time. I think most motorcyclists are intelligent enough and mature enough to keep their bikes quiet. The rest of you are the ones who are going to lose in the end. Hopefully you won't take us down with you. I don't care if you like it or not. I won't tell you to go F yourself either. I will just hope that you grow up.


Posted by: donfitz69---------------------

<Mod edit>

I've had my fill of this jerk and his inability to act like an adult so he's GONE.

Thanks to those of you who gave me a heads up on this.


Posted by: geremacheks---------------------

Hey Don, you having a Fitz, or what?

Yeah loud pipes, you can hear them coming, for awhile anyway, then you have to get a hearing aid like me. Then they aren't so loud anymore--cause your ears are destroyed.

Here in Wis, the DNR watches mountain bike trails carefully for erosion. Too carefully in my opinion. But at the same time deer and elk are eroding trails day after day, year after year....but I guess this is natural....like tornaoes, floods, fires, typhoons and earthquakes.

Do you hear all the fuss about getting snowmobiles out of Yellowstone to purify the air. Remember these machines are on the roads, not trails. Well, I'm in Yellowstone every year when the tourists thin out in October and early November. No snowmobiles yet at these times. Near Mammoth, I can't even breath the air without getting sick to my stomach. Why? The parks utility trucks and private contract trucks are all over the place, back and forth, doing projects. 95% of them are diesel. And you can hardly breath with the diesel stench in the air. And nobody's doing much about it.

Goooo-re? Clinnntonnn? Why waste words.

Hey Don, Don't try and talk like the people in the Hollywood movies you watch. You can talk to us like an adult. Make your points with a little finesse. We'll listen.


Posted by: MCassle---------------------

I was recently sound tested at a D37 qualifier, came in at 87 dbs with the stock exhaust on my 97 KLX300.

Matt


Posted by: Shawn Mc---------------------

I believe down in my heart that the noise issue is nothing more than an excuse to limit OHVs' of all types. I ride a YZ426 with an aftermarket pipe, and ya its loud. As a matter of fact, I think it has effected my hearing. But that doesnt give anyone the right to take it away from me, or my right, because thats what it is, a right, not a privelige, to ride where and when I want.


Posted by: stroker---------------------

Up here in Canada they are trying like crazy to shut down riding areas. We are being pushed out by every other user group. Most of the complaints are noise and stupid guys riding on the roads like idiots trying to impress others. Even I and avid riders find it annoying to see bikes roosting in the pits or riding too fast on public roads. The saftey of others is more important than our right to ride. Riding should be in designated areas and one should ride without having to jeopordize others. If riding is important to you then you should do your best to understand what others are complaining about then try to accomodate them as best as you can before they shut us down. Unfortunately there is more of them than us and when it comes to a fight we will lose. Take the time to educate the ignorant riders and we will have a far better chance.


Posted by: geremacheks---------------------

I'm with you stroker..........but is it too much to ask for all the air traffic that flys over the places we ride to keep it down too? My gosh, they are miles away and we can still hear them. And helicopters actually shake the trees and ground. I think we should open our mouths and complain. That may take the focus off of us for a change. Let's give the WHOLE picture.


Posted by: stroker---------------------

You might be right there, but again you got to remember more people fly or need use planes than people that ride dirt bikes `so again you are picking a fight that we can not win. If they do shut down plains because of the noise you can be sure they will shut down motorbikers first. It would be better to spend your energy teaching bikers to be more compatible with other user groups so these groups would not see us as a problem but a soulution . Then maybe when things get rough these groups may come to our aid . Up here in Canada at one place I ride the dirt bikes have made a bond with the horse back riders. We have helped them with trail maintance and have shown them that we have been educating our riders to not spook their horses and they have stopped thier kind from protesting our existance on the mountain we ride. I know it sounds like a bunch of work and ass kissing but the truth of it is ,if they really wanted to they could get us removed. In fact since then, the mountain bikers and us have had a political battle in our area and it was the horse people that saved us by joining in our fight to have privledges on the mountain. Unfortunately ,I see in the future smaller riding areas farther away from the cities as populations grow but if we smarten up now it will take them longer to shut us down.


Posted by: NVR FNSH---------------------

Quote:
Originally posted by Shawn Mc
I believe down in my heart that the noise issue is nothing more than an excuse to limit OHVs' of all types.


Sorry, but I have to disagree. I'm one of those fellow riders that doesn't want to hear your obnoxiously loud bike when I'm out riding & stop to take a break. I also want to see more OHV opportunities not less. Go figure.


Quote:
Originally posted by Shawn Mc
I ride a YZ426 with an aftermarket pipe, and ya its loud. As a matter of fact, I think it has effected my hearing.


Gee, if you think it's affecting your hearing how do you think other people feel about it?

Quote:
Originally posted by Shawn Mc
But that doesnt give anyone the right to take it away from me, or my right, because thats what it is, a right, not a privelige, to ride where and when I want.


Absolute horse poop. Ever heard of property rights? Now, if you're only refereing to public land - BLM, USFS - you have somewhat of an agruement. But I don't think you'll find anyone on this site that believes OHVs belong everywhere. There are areas that we should not be riding.

If you think it's your right to run any exhaust you want why aren't you taking your case to the supreme court? I'm sure all the vehicle manufactures would appreciate it if you could get those pesky noise limits thrown out. Or how about any ordinances that control/regulate noise emissions from stationary sources - factories, generators, mines etc?

Brian


Posted by: Put-Put---------------------

Hey Y'all,
I was just passing through this forum on my way to the KDX page and noticed the racket. My best friend rides a YZ 400 with a stock pipe. I ride an '01 KDX with a stock pipe. The noise difference is notable to say the least. However, what was said above about the aftermarket 2 stroke pipes is and are partially true. A couple of buddies of ours ride 250s with the PC Factory Sound S/A's and together they are truly obnoxious, but nothing like my buddies 400 when it gets wound up, so he's looking into a more quiet aftermarket pipe. I feel that we should't get into a finger pointing match here b/w the 2 strokes, 4 strokes, and sleds. I grew up in Maine and spent some time on sleds, I think that the reason most people don't complain about them too much is that A. you usually don't concentrate many of them in one small area and let ride them around in circles on a regular basis. B. Most "tree-huggers" aren't out doors when the temp. is around freezing, hence less complaints. C. Sleds really aren't as loud as bikes. Now, I have to admit that I do get a bit ticked off when I'm out at the OHV area with my family resting in between rides when Bubba the 300lbs moron in overalls with out a tee shirt on rides by on a dilapidated quad, fenders flapping and suspension maxed out with a very loud, very un-packed, very four stroke pipe/S/A that sounds leaves my ears ringing. Most posters on this thread are correct, we need to police ourselves up otherwise somone else will do it for us. My buddy is right now surfing the net looking for more silence and better horsepower, me, I'll continue to enjoy roosting Bubba on my stealth KDX Let's get our act together and rope in the loose ends. See y'all on the trials


Posted by: Shawn Mc---------------------

NVR FNHS-Brian my point is clear, and yes my problem is with the BLM and the USFS and the same ILK.

My point is, if our bikes made no noise whatso ever, they would still be out to make sure nobody could ride. Its not the noise, its the act. The greenies and the ilk, see us as some kind of threat, and the whole thing is a control issue plain and simple. The sound is an excuse to limit the action. Same as the perported gas mileage B/S and the SUV's. Greenies dont like them either, they say that they put others at risk in a collision. Thats strange, my family is safer in an SUV. They say thats not FAIR! FAIR, since when has life fair? Its all just control and a prelude to another tax grab. This whole subject burns me to the core. I have a constitutional right to persue happiness.

I have no problem with someone coming out of they're dwelling and giving me a huge dose of crap over my motorcycle being too loud. AT that point, I'll turn it off and push it away. But when Im 5 or 6 miles from the nearest civilization, how loud my motorcycle is, nobodys damn business but me and the surrounding rocks. Can I sue the greenie jackass over the use of the bullhorns they use? Bet no. Bunch of damn devil worshipers.


Posted by: karlp---------------------

Had to comment on this, because it is effecting my riding areas. And that was to be expected!!!
Lots of high output 4-strokes hitting the woods. Every one of them seems to need to buy an aftermarket muffler for a "horsepower gain" they probably can't notice or use. Dozens of us used to ride all day, 2 and 4 strokes, and nobody knew we were out there. Now the barbed wire is going up, and the police are coming around, rather than chasing real criminals.
I ran into a guy walking one of the trails the other day. He was putting up no trespassing signs. He said I couldn't ride out there anymore. I said "you'll never know I'm here" . He had to agree.
Went to a sound test at an enduro a couple of months ago. The inspector asked me to start it up. I twisted the throttle for him.
I ride an XR400 with a slightly modified stock exhaust. I don't need to pay $300 for a horsepower gain i don't need. My buddies all did, and I can still smoke them!!

Karl P.


Posted by: Rodzilla---------------------

Quote:
Originally posted by Shawn Mc
NVR FNHS-Brian my point is clear, and yes my problem is with the BLM and the USFS and the same ILK.

My point is, if our bikes made no noise whatso ever, they would still be out to make sure nobody could ride. Its not the noise, its the act. The greenies and the ilk, see us as some kind of threat, and the whole thing is a control issue plain and simple. The sound is an excuse to limit the action. Same as the perported gas mileage B/S and the SUV's. Greenies dont like them either, they say that they put others at risk in a collision. Thats strange, my family is safer in an SUV. They say thats not FAIR! FAIR, since when has life fair? Its all just control and a prelude to another tax grab. This whole subject burns me to the core. I have a constitutional right to persue happiness.

I have no problem with someone coming out of they're dwelling and giving me a huge dose of crap over my motorcycle being too loud. AT that point, I'll turn it off and push it away. But when Im 5 or 6 miles from the nearest civilization, how loud my motorcycle is, nobodys damn business but me and the surrounding rocks. Can I sue the greenie jackass over the use of the bullhorns they use? Bet no. Bunch of damn devil worshipers.


Shawn, I agree with you up to a point.

I agree that no matter what, the green agenda does not include OHVs silent or not. This is not the point. Nor is this a "give them an inch, and they'll take a mile" issue.

Instead this issue is about the "mom and pop" forest user, the couple in their RV, the day hiker and the equestrian. They are generally not affiliated with any green group. Just average Joes like you and me out to enjoy mother nature.

But when bikes with loud pipes can be heard 2 or three miles away, then you are affecting others rights. It is these "average" people that place the calls to the rangers and the cops. Not necessarily the Sierra clubbers. They carry a lot of weight. In many ways a lot lot more weight than the "greenies" who cry wolf at everything. These are the people we need on our side! The Forest user with no green affiliation. If John Doe sees a petition or a movement to close an area to OHV's and their only memory is of loud dirt bikes ripping around or God forbid A-T-Vs doing donuts in the parking lot, they are much more apt to support such a closure.

If by your logic that loud pipes are your "right to the pursuit of happiness" then is the idiot who dumps his old water heater in the woods or leaves his camp site trashed within his rights, if it makes him happy?

The point is, that if the people who never touch the trails we ride on, the car campers, the couple in their RV, etc... never know we are there, they have no ammo. If they can hear us "pursuing happiness" from the next valley over then we risk losing.

Rod


Posted by: stroker---------------------

Rod , you make an excellent aguement , I think if all dirt bikers could get on line with you and your attitude we could crush the greenies like the bugs they are. If we act like good neighbours always considerate of others then they will back us or at least leave us alone. I'm with you.


Posted by: Rodzilla---------------------

Thanks,

We're all in this together. We just all need to see the big picture.

Rod



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