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A personal 4 stroke Revelation . . .
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Posted by: robwbright---------------------

As most of you know, I've not personally noticed a huge difference in lap times between 2 strokes and 4 strokes at my local track which is tight and has basically no elevation changes. 2 or 3 of my friends went from late model 2 strokes to late model 4 strokes this year and they basically kept finishing in about the same places in their classes - they weren't getting faster any quicker than I was. Sometimes I'd beat them and sometimes they'd beat me.

The one exception was my friend who went from a 1996 KX 250 to a 2006 KX450F. He moved up a whole class in 2 races - finishing about the same place in the higher class as he was in the lower one. I credited the suspension and handling of the decade newer bike as much as I credited the motor.

However, I recently went to another track nearby to test my injured wrist and see if I was going to be able to race. The track is hardpack and is built completely on a pretty steep hillside and has 4 pretty large doubles - one is uphill out of a 180 corner and measures 56 feet with a blind takeoff. The others are between 43 and 50 feet. There are also two uphill step-ups that require really getting on the gas to even come close to clearing them on my RM - and I usually didn't make it.

Anyway, the only one of the 4 doubles I have attempted in my two visits to the track was the 43 foot one. The others are just too difficult to get sufficient traction on the RM and are too risky.

On their 1st or 2nd visit, my buddies on the 4 strokes - 250s and 450s - were all jumping most or all of the doubles, and clearing the uphill step-ups.

Note, again, that we are all within about one half second per lap on the flat local track - but I simply cannot do what they are doing on this hard, hilly track.

So, I guess that means I'm one step closer to moving over to the "dark side".

You were right Okie (and others).

And no, I can't race. I reinjured the wrist at the track on one of the step ups and finally went to a specialist. He found a scaphoid break that my chiro couldn't find in two different visits with x-rays. The Ortho could only find the break on one of the 7 x-rays I had previously had taken. Thus, I'm in a pretty neon green cast for 5 and a half more weeks.

Posted by: kdxtodd---------------------

Quote:

Originally Posted by robwbright

So, I guess that means I'm one step closer to moving over to the "dark side".

Don't do it!!!!!!!!!!

Posted by: ellandoh---------------------

so youre telling me you saw no other 2t's clearing these jumps?? what they have over you is automatic traction control, try some more, focusing on your throttle control, ride up higher on the previous berm to get a longer run up. also if youre not used to hardpack on a 2t, it takes a while. you and your buds all have the same types of tires??

dont give up yet man , it is worth the extra effort IMHO..........at least until the EFI comes out

Posted by: john3_16---------------------

You'll regret it on your first valve job...

Posted by: MXP1MP---------------------

one word for ya man "skill" just jumpin on a 4 stroke isn't gonna make you faster your whole reply is all doubt filled and it's you, not the bike.

Same thing will happen if your on a different bike it won't just magically make you better, I can see it now a year later man I miss my light flickable 2 strokes. You was beat mentally before you got on the track that day.

Posted by: Chili---------------------

Quote:

Originally Posted by MXP1MP

one word for ya man "skill" just jumpin on a 4 stroke isn't gonna make you faster your whole reply is all doubt filled and it's you, not the bike.

Spoken like someone who has never experienced the advantage the 250 4 strokes have over a 125. I'm a 2 stroke die hard and would love to keep my kid on his 125 but to deny the advantage is just plain insane.

Posted by: KDX CRAZY---------------------

Its hard to believe that a 250 2t would have trouble with something that a 250 4t can handle .

Posted by: Chili---------------------

Quote:

Originally Posted by KDX CRAZY

Its hard to believe that a 250 2t would have trouble with something that a 250 4t can handle .

Not sure where that was ever part of the equation in this thread?

Posted by: FruDaddy---------------------

Quote:

Originally Posted by Chili

Not sure where that was ever part of the equation in this thread?

Quote:

Originally Posted by robwbright

On their 1st or 2nd visit, my buddies on the 4 strokes - 250s and 450s - were all jumping most or all of the doubles, and clearing the uphill step-ups.

Rob, don't forget that you were riding with a bad wrist. When you heal, try again.

Posted by: Chili---------------------

Fru are you pointing to the second quote as verification that a 250 2t was struggling with something that a 250 4t was doing? I read it that' Rob's buddies on 4t's both 250's and 450's were clearing the jumps.

Posted by: FruDaddy---------------------

I forgot that Rob isn't riding a 250, my bad. The 144 should be able to keep up with the 250 thumpers, but maybe not the 450's.

Posted by: robwbright---------------------

The first time I was at the track I was completely healthy and I wasn't even close to trying anything but the 43 footer.

For a long time I've been a die hard stroker to the point that people here have said that I "hate" 4 strokes. I'm pretty good at keeping the 144 on the pipe - I'm no Ryan Hughes, but I can get on it pretty good. My opinion before was that a 250f would be faster the longer the race was, but that it wouldn't really improve my lap times in the first 4 or 5 laps - and that still appears to be true on a tight, SX style track with no elevation changes.

I also understand that it's mostly rider, not bike. I have no doubt that an "A" rider or even a "B" rider on my bike could clear all of these jumps with no problem.

What I'm saying is that 2 "D" class riders on 250f's are clearing an uphill 56 foot double out of a 180 degree hard pack corner. The jump face is only about 3 1/2 feet high and is actually angled in relation to the landing so that you have to jump it at an angle. Short of the 65-70 foot triple at another track nearby, it's the most difficult jump I've seen on the tracks within an hour of here.

My buddy Ryan (2005 CR250F) tried it tapped out in 3rd gear, cased it badly - face of the landing - and totally screwed his ankle, which he taped up and tried again. To clear it he has to be full throttle 4th gear. As my bike is set up now, I would need to be in 5th, so I'd have to exit the corner in 2nd, shift 3 time perfectly and hit it. Ryan has to exit the corner in 3rd, shift to 4th and hit it. That's an advantage.

At the last race Ryan decided to try the "C" class. He finished last in heat and last in final - and didn't crash at all. He wasn't making up any ground on anyone. I've raced C on 3 or 4 occasions and finished mid pack.

For the 43 footer I have to be 2/3 throttle in 4th gear, and the exit corner is a 2nd gear corner. The 43 footer is no problem - I was jumping it with a broken wrist - but it's also a 2 1/2 foot high jump and it's downhill.

The one uphill "step-up" (kindof a catapult) of sorts is out of a tight 90 corner with about a 25-30 foot run in. It's very steep. My best effort has not managed to get my front wheel on the upper section.

By the way, my natural inclination has been to overstate how long jumps are. I would have guessed that the new triple at our local track was 55 feet. I stepped it off at 19 steps - since I'm very short, that's about 40-45 feet at most.

The 56 footer and 43 footer I'm referring to at the hilly track were actually measured, so they're for real.

I love 2 strokes, but I couldn't deny the 4 stroke advantage there.

BTW, one of the local fast kids got a YZ250f this spring. I asked him the other night about maintenance. He has adjusted the valves a couple times, replaced the piston and ring, and changes the oil every weekend. That's it. We'll see how it does in the next year or two, but he's certainly having no difficulties this season.

Posted by: CaptainObvious---------------------

What makes a king out of a slave?

Courage!

What makes the flag on the mast to wave?

Courage!

What makes the elephant charge his tusk in the misty mist, or the dusky dusk? What makes the muskrat guard his musk?

Courage!

What makes the sphinx the seventh wonder?

Courage!

What makes the dawn come up like thunder?

Courage!

What makes a four-stroke make the double? What gives a thumper the advantage in a whole-shot? What have they got that I ain't got?

Courage!

Posted by: robwbright---------------------

Quote:

Originally Posted by CaptainObvious

What makes a king out of a slave?

Courage!

What makes the flag on the mast to wave?

Courage!

What makes the elephant charge his tusk in the misty mist, or the dusky dusk? What makes the muskrat guard his musk?

Courage!

What makes the sphinx the seventh wonder?

Courage!

What makes the dawn come up like thunder?

Courage!

What makes a four-stroke make the double? What gives a thumper the advantage in a whole-shot? What have they got that I ain't got?

Courage!

Huh?

Posted by: CaptainObvious---------------------

Quote:

Originally Posted by robwbright

Huh?

What, you never saw the movie "The Wizard of Moto Oz"?

A two-stroke 125 can do anything that that a 4-stroke 250 can do (except win races - sorry, I couldn't help myself). The difference I have found between the two is that the 4-stroke, with its low-end torque, provides the rider with a lot more confidence (courage).

Jumps become much easier on a 4T. Powering out of a turn is easier on a 4T. Confidence is one of the biggest factors in improving your riding ability.

Posted by: Ol'89r---------------------

[QUOTE=CaptainObvious]
What makes a four-stroke make the double? What gives a thumper the advantage in a whole-shot? What have they got that I ain't got?
QUOTE]

Torque and traction.

Posted by: Masterphil---------------------

Any incarnation of a 125 will have less bottome end power than a 250f. This helps significantly when you don't want to(aren't able to) be in the proper gear and on the pipe all the time.

Apples to oranges, but there are few jumps that I can't clear just by twisting the wrist and preloading, even if I totally blew the corner before the jump. Preloading and seatbouncing can add quite a bit of distance to a jump.

Corner speed is the key on a 125, the end.

Posted by: MXP1MP---------------------

Quote:

Originally Posted by Chili

Just an FYI I owned an '03 YZ 250F for a good year ridden many times my friends '01 model that was 280 big bored and a few times on the CRF

yea I guess I don't know what a 250F is like

Posted by: elliot-cr133---------------------

Quote:

Originally Posted by CaptainObvious

What makes a four-stroke make the double? What gives a thumper the advantage in a whole-shot? What have they got that I ain't got?

Quote:

Originally Posted by Ol'89er

Torque and traction.

Well said.

Posted by: Chili---------------------

Quote:

Originally Posted by MXP1MP

Just an FYI I owned an '03 YZ 250F for a good year ridden many times my friends '01 model that was 280 big bored and a few times on the CRF

yea I guess I don't know what a 250F is like

So in your experience the 250F has no advantage over a 125? Must be right, I mean if it was an advantage all the pro's would have switched from 125's, oh wait....

Posted by: robwbright---------------------

Quote:

Originally Posted by Masterphil

Corner speed is the key on a 125, the end.

Well yea - are you sure you aren't captain obvious?

That's the reason the A or B rider I spoke of could clear the 56 footer on my bike and I can't. The A/B rider could exit the corner in 3rd and only have to shift 2x's. Or he might make it if he seat bounced in 4th.

The 250f allows the rider the same speed as me to exit the corner in 3rd because of the low end power and he only has to shift once - whether that's because of his gearing or whatever.

I have no doubt that my bike can do it with the right rider. But I know that I'm not likely to make it given my low corner speed. I also know that if Ryan can make it on his 250f, I could also make it on a 250f.

In short, the point I was getting at is that the 250f is easier to ride in that situation and therefore would be faster through that section for me and for Ryan. It would probably make little difference in that section to an A rider who could clear the same double on either bike.

Posted by: robwbright---------------------

Quote:

Originally Posted by MXP1MP

one word for ya man "skill" just jumpin on a 4 stroke isn't gonna make you faster your whole reply is all doubt filled and it's you, not the bike.

If you've read any of my posts before, you'd know that until that day at that track, I've seen little difference in my friends' speed and ability because of their switch from 2 to 4.

However, the difference was notable in that particular situation and on that particular track.

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

This is done.

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A personal 4 stroke Revelation . . .

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