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Who's right on fork spring rates?
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Posted by: redsput---------------------

I looked at the FRP site, and the suggested fork spring says .38 kg. Checked the chart on the race-tech site and it says .43 kg. BIG difference - now I'm not sure what the heck to order. Any thoughts? I'm about 190 in gear, ride recreationally about 50/50 track and trails. Semi-fast for an old guy - but no supercrosser... Riding an 02' KDX220r

Posted by: Green Hornet---------------------

Jeff's recommendation is from experience. E-mail him and ask. He's a great guy and will respond

Posted by: css_elfers---------------------

I went with the 40kg xr 400 springs. I'm 185, 6' and ride mostly trails and tracks but no big triples. I got a 05 220.

ELF

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

NOBODY knows your bike like Jeff. End of story.

Posted by: Colorado Mike---------------------

I think Racetech is a little heavy on their estimations, but maybe that's just me. I'm 47, weigh around 185 in gear, ride mostly tight technical trails. I put the XR 400 .38 Kg/mm springs in my forks and like them a lot. For you though, I would think you would be happier with the .40s than the .38s, because you sound like a more aggresive rider, spend more time on MX tracks, and are a little heavier. You may even like the 42's. If I recall correctly, Racetech recommende the .42s for me too, and I don't think those would work for me. BTW, last week I did go to a track and the .38s worked well for me on mid-sized jumps and were good in the whoops too. My old springs were scary on jumps and steep downhill braking in rough terrain. I'm much more cofident with the new ones.

HTH,
Mike.

Posted by: sether---------------------

Quote:

Originally Posted by redsput

I looked at the FRP site, and the suggested fork spring says .38 kg. Checked the chart on the race-tech site and it says .43 kg. BIG difference - now I'm not sure what the heck to order. Any thoughts? I'm about 190 in gear, ride recreationally about 50/50 track and trails. Semi-fast for an old guy - but no supercrosser... Riding an 02' KDX220r

Just to fan the flames Kawasaki's heaviest replacement is:

SPRING-FRONT FORK,K=0.37

Here's KawasakiSportCenters recommendations:

KDX200-H9 & KDX220-A10
135-150 0.34 Light 95mm
150-170 0.35 Stock 95mm
170-200 0.36 Heavy 95mm
200+ 0.37 Ex-Heavy 95mm

Explain this to me? Is it because of the stock spacer or what?

Posted by: KI4CPE---------------------

I encountered the same confusion when I went to FRP and RACE TECH. I weigh about 210 lbs. I ride a little track, but 90% trails. FRP's highest was .38, but RACE TECH reccomended .44 for my large carcas. I think the 44's would be a little stiff for what my abilities are. I probobly need the 40's, or better yet talk to jeff and get the real scoop on the fork setup for me.

Posted by: tominator---------------------

I have a nearly new set of (FRP) 0.40s in my garage (make an offer!) and a new set of RT 0.44s in my forks. I'm about 185# and I think that the 0.40s are too soft. Here's why: I talked to Jeff and he explained how I should set the preload to get the front-end sag right (worked out 27mm). I used the Gold valves with Jeff's valving recommendations. The front end was pretty comfortable, but the back end was either kicking and swapping like a frog in heat or hard as a stone. I read every post on the web about shock tuning and tried every clicker combo there is. Finally, I got the local guru (Bob Riker) to revalve my shock, I figured that would fix it. No luck, still trying to throw me off. Bob told me to call the engineer at race tech. I did. He suggested the bike was not balanced. So I bought the 0.44s and set the GVs up with a little less high speed damping. Wow! Now I can sit down and haul ass at the same time!!! My shock is at 14-12 comp / 11-9 reb and my forks at 10-12.The bike is much more balanced, comfortable and controllable.

As always, individual riding style and personal preference are the only things that really matter. For what it's worth ... my 2 cents. Good luck. I'm sure that you'll get it dialed in.

Posted by: Rhodester---------------------

I had Jeff revalve my shock and put Gold Valves in my forks. They were still too harsh on high speed compression so I sent them back for an adjustment....still too harsh. I then decided to dig into them myself. I set my fork low speed compression at cL8 which worked well. I set the high speed comp at cH3 which was still too harsh. I just reset the forks to cL6 and cH1 looking for more plushness. On the shock I pulled out a couple of the large shims on the high speed stack. I have yet to ride it since I have the bike apart for some other work I'm doing. I'm using the stock rear spring and Eibach XR400 .43kg springs in front.

Posted by: 80elkster---------------------

I just put a FRP 5.2 spring on the back and a set of .42s on the front. I weigh in at 250. I've got the clickers set at per Jeff's softest settings, 6 on the forks, 8 on shock (rebound), and 6 on the compression. I just changed the fluid in both the forks and the shock used Mobile 1 ATF (7.5 wt). I'll be takin her out for a ride next weekend to experience the results. I ride tight technical trails with lots of ruts and tree roots. I'll give some feedback when I return.
P.S. I have a 93 200 with the upside down forks and my son has a 2005 200 and the last time we rode he jumped on mine and found it much more plush on the trails although I believe his is a little stiff as its still not broke in and he weighs around 235.

More to come.....

Posted by: 80elkster---------------------

I was happy with the rear suspension but the front is too stiff for my liking. I talked to Jeff and he said ship the springs back to him and he would trade me for the next lighter springs (.40). He's a cool guy!!!

Posted by: spivv39---------------------

I am guessing that I am about the same size, weight and skill level as both you Redsput and probably Colorado Mike too. I am a little younger but not much and i too ride trail, track and hare scramble.I have a 2000 220 and I went straight to a set of .40 springs as i had them from my XR400. I liked them but I now have fitted a set of .42 which I prefer when racing but the .40 were probably better on the trail. FWIW I am running the standard shock spring!
However as many have said we are all different and prefer different settings but my guess is that you need to try .40 first and then maybe .42.

Posted by: kmccune---------------------

I weigh 155 and use the .40s,they work well for me. They are a little stiff for most trails...but then they are a little soft for a full on MX track to make up for it.

Posted by: Green Hornet---------------------

I followed Jeff's recommendation and put .38's in mine. I'm 6'00", 182 w/o gear. Had them installed by a suspension guy who put oil in 4inches from top, as per Jeff's recommendation. They work great. Just because something works out on paper does not mean it works in real life-ARGHHHHHH

Posted by: tptp---------------------

Just changed to .42 due to RaceTech advic I am 73kg/160lb w/o gear and it seams to be to stiff. The spring is longer than stock so I have to adjust for 10mm preload and aim at 30mm sag. Will use 5W oil and 100mm oil level, compression clicks at 17?
Stock spring was far to soft for me riding slow MX :-)
RaceTech seams to be rather high in their recomendations, I think, at least for KDX.

Posted by: Green Hornet---------------------

for an MX not. The KDX is not an MX bike. Those springs are way to stiff for your weight

Posted by: tptp---------------------

Well, thats for shore. But it is what RT recommend for a KDX at theire webpages...Let's se if it possible to mod them. And yes I know KDX are for the woods, but I'm riding for fun and do not like running :-) Besides it's a little hard to find trials and woods where I live.

Posted by: Green Hornet---------------------

If you have not had them revalved, maybe that will help some what, other wise sell those springs and go a bit lower

Posted by: tptp---------------------

Yes working on it - but seams as RaceTech recomends rather stiff springs.

Posted by: tptp---------------------

.42 springs in the fork and clicks fully out, two shims removed in the valve, the bike handles better than before. I will go on with my suspension tryouts and learnings :-)

Posted by: StuckinJersey---------------------

I have a 96 KDX 200 and the forks had a lot of dive in them. Went with Jeff's recommendations and it was better but still not great. I'm at 6 ft. 178 lbs. I went with the .38 and wish I had gone with the next size up. The .38 is really plush in the rock gardens but when running down hills and turns the nose would still dive a bit. Ended up getting a nice set of CR forks for her, that fixed everything because they were already worked and had a rebound adjustment on them. I find the old KDX forks rebound really fast and only thing that dampens it was a 7w or 10w fork oil (caused the piston to move alot slower in the fork.) so even with the heavier spring the fork still doesn't want to play nice.

Posted by: kx250kev---------------------

The one thing everyone here agrees on is that the stock fork springs are TOO SOFT! I went with .37kg springs from Kawi, and for trail riding, they work great for my 180lb + gear weight. If you do more than play ride on a MX track, you'll definetly want to go stiffer. The good news is that they are super easy to change, so experiment to find what you like best. I'm satisfied with my forks, and I didn't have to spend a fortune to have them revalved. ; )

Posted by: Jeff Sexton---------------------

I used Race Tech's recommendations (both valving and springs) on my '02 KX250 and ended up with suspension that left me with shoulders that ached for a week and blisters on my backside that nearly made me cry. It seems they are universally heavy in their recomendations. Not only that, but I tried calling them and e-mailing them for two weeks to find out what I should do about it and got exactly zero response.

By all accounts, Fredette is a first class guy and very few know as much as he does about how to get the most of of the KDX. Do yourself a favor. Trust him!

Posted by: matt-itude---------------------

im 230 without gear i have an 03 200. I no pro but because the bike sagged in front so bad it didnt handle right. I put some 44s in the front that made it to harsh but made the diving and sloppy feel in the front go away. I removed 2 shims from my valves in the forks and for the cost of a set of springs I absolutely love the way it works now.

Posted by: Jeff Sexton---------------------

Taking two shims out seems to be the concensus. Which two?

Posted by: matt-itude---------------------

I know where you are coming from. There should be 10 on each stack in your 04 all 10 are identical. It makes a huge difference and costs $0 if you do it yourself (and don't break the base valve

)

Posted by: Jeff Sexton---------------------

Right on! The forks are sitting on my bench. Now if I could just find that 14mm allen socket!

Posted by: 80elkster---------------------

I tack welded a 14mm nut and bolt together then used a socket. Works if you got a welder and of course a nut and bolt.

PS If you haven't allready read the "Shim stack front suspension" thread you may want to take a look, there is a lot of good info there.
Here is link to that thread below:
CLICK HERE

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Who's right on fork spring rates?

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