Need .40 springs???

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#1
Consider using a set from a late model XR 400. They are the same diameter as used in the later KDXs, are hot wound and .40kg/mm.

They ARE about 4" longer than the OEM KDX spring, so you can get rid of the steel spacer in the kawi altogether.

Why they put a steel shank where spring should be escapes me. The XR springs now in my bike (and in my riding buddies' bike for months) are just plain wunnerful! Superior for sure to the 470mm shorties (aftermarket) that were in.

And I'll bet'cha they won't be collapsing like the aftermarket springs I had, too! After a handful of rides, one of the new cold wound springs was 5mm shorter than the other!!

Christmas valley, here we come!!!!!!!!
 

gonzodog

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#2
Stiffer Springs from XR400?

Excellent idea to use a longer spring and dump the spacer - (I guess Kawasaki figured out that low carbon steel spacers are cheaper than extra length on the fork spring.)

Anyway, do you have any suggestions for a low cost source for the Honda XR springs? Is there any particular year or just 96 on?

Thanks in advance for any info, and, best regards.

Gonzodog
 

fatty_k

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#3
Yes, I am also interested in these fork springs. I keep hearing good things about these springs with 8-10mm preload spacer (or none at all I guess) and the Fredette .39's with the stock spacer. CC, are you saying the aftermarket (Fredette) springs wear down (collapase)? Is that just an issue with the hot vs cold wound? When they collapase, you must increase the length of the preload spacer correct? Now if you are using the stock 90mm spacer, adding to that isnt a very good thing is it? Thanks for helping out a suspension newbie/spode.
 
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#4
I am using aftermarket Eibach springs (to suit XR400) and I have had no problems with them.
 
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#5
A few things here on the Xr400/600 springs. Those forks first off are 43mm units. So you have to have 43mm forks to install those springs (86-92, 95+ 200 or the 91-94 kdx250). Honda has varrying rates on these springs through the years. Here is a breakdown on the specs:

Xr600 93-00 : .41
Xr600 85-92 : .42

Xr650L 93-02: .44

Xr400 00-02 : .41
Xr400 96-99 : .38

Now if you buy aftermarket springs for the honda forks, you have to use spacers since the aftermarket springs are shorter. I ended up bottoming the forks on the spacer on the xr600 with the .45 eibach and a spacer. I solved the problem by stacking a valve spring from a 302 Ford motor on the top of the eibach spring. It came out just about right on spring rate and kept from bottoming on the spacer.

Now if you have the older KDX200s like the 93-94s with the 41mm forks, you can use the springs from the Xr250s. Same diameter forks.

Xr250 96-02 : .35
Xr250 90-94 : .40
Xr250 86-89 : .38

So you can find springs out there from other bikes. Just make sure the forks are the same diameter there. If the spring is to long, you can either cut or take out the spacer or you can cut the spring down but that will change the rate slightly.

Where to find springs? Check any of the 4 stroke or XR boards. Ebay is good also. I am sure many XR pilots have them in their garage since most of the XRs are undersprung stock.

http://www.justxr.com
http://www.hondaxr.com
http://www.thumpertalk.com

All good places. Hope that helps some. Also most MX bike from about 86/87-90/91 had 38mm forks. The CRs did from 86-88 and has a .36 or .38 spring in them. The White Brothers Catalog has a lot of info on the spring rates there: http://www.whitebros.com Just check their offroad catalog. Then use the Racetech site to reference the size of the fork for the bike. Works pretty well using both sites.
 
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#7
Or the Xr600 springs. It will probably be easier to find the 600 springs. I have a set in my garage. I would trade someone with some .37/.38 springs
 
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#9
Anyway someone could please update the spring rate part of this thread?

Thanks!

John C.

Matt90GT said:
A few things here on the Xr400/600 springs. Those forks first off are 43mm units. So you have to have 43mm forks to install those springs (86-92, 95+ 200 or the 91-94 kdx250). Honda has varrying rates on these springs through the years. Here is a breakdown on the specs:

Xr600 93-00 : .41
Xr600 85-92 : .42

Xr650L 93-02: .44

Xr400 00-02 : .41
Xr400 96-99 : .38


Now if you buy aftermarket springs for the honda forks, you have to use spacers since the aftermarket springs are shorter. I ended up bottoming the forks on the spacer on the xr600 with the .45 eibach and a spacer. I solved the problem by stacking a valve spring from a 302 Ford motor on the top of the eibach spring. It came out just about right on spring rate and kept from bottoming on the spacer.

Now if you have the older KDX200s like the 93-94s with the 41mm forks, you can use the springs from the Xr250s. Same diameter forks.

Xr250 96-02 : .35
Xr250 90-94 : .40
Xr250 86-89 : .38


So you can find springs out there from other bikes. Just make sure the forks are the same diameter there. If the spring is to long, you can either cut or take out the spacer or you can cut the spring down but that will change the rate slightly.
 
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#11
I have a 1994 KDX250 (inverted forks), and would like to replace the fork springs.

I called race-tech, and they basically said everything had been discontinued, and "good luck".

I'm 200lbs with no gear, and trail ride the desert here in Tucson, AZ. Lots of steep rocky hills, "Baby Head" boulder fields and a few bumpy straightaways. I'm a decent rider, and consistently ride as fast as I can.

I'm looking at .42 springs, and had heard that 00 and on XR400 springs are a direct replacement.

Is this true?
Any major changes to the stock shims, oil or clickers?

Thanks!

John C.
 
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#12
Have you considered keeping the stock springs and just losing 130 pounds? :-)

What is your weight in full riding gear?

Is there some reason you are wanting to go with "just" .42 rate springs? I would think .45 or .46 would be better if you are around 215 in full gear. Besides giving the correct amount of sag, it will make the bike sit up higher and hopefully avoid some of the rocks below.

None of the XR400 springs will fit properly inside 1991 - 1994 KDX250 forks. Besides fit, they are just .38 (early years) or .40 (later years), so those are not correct for your bike/rider combined weight, anyway.

Try Eibach 989 with a PVC or aluminum spacer. It worked great for me. Race Tech 3949's may also work.

I would suggest that if you are willing to put the time into it, you can make them work more to your liking. Try starting out with the minimum amount of oil listed in the manual, then make changes with your compression damping adjusters. If you can't get it stiff enough, THEN add more oil.

As with any KDX cartridge fork, a Race Tech Compression Gold Valve kit will be an improvement. You'll have to calm down from the spring change to get your head right and worry about that later, though. :-)

Good luck with it.
 
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#13
Thanks for the reply...

So it sounds like if I try the Eibach 989, measure from the top of the installed spring to the bottom of the bottomed out fork cap, and then add 10mm, I'll have a starting place for a working suspension, right?

Any idea what diameter PVC works best?

Thanks!

John C.
 
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#15
just a quick note on the issue of spacer length. it has to be calculated depending on the length of the spring and how much sag you have compared to how much sag you want. when people say use X amount preload thats not the spacer length, rather its the amount the spring is compressed by when you assemble the fork. even if you work out your spacer length and preload correctly it still may not have the correct amount of sag for you weight so you may have to go back and add or subtract preload to get the sag right (normally 30-50mm i believe).
just my 2 cents..
p.s.
i have used 01' xr400 springs and they worked really well for me, a much better bike now!