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Shim Stack Mod Photos

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I decided to do the shim stack mod, and there was really nothing to it. All that needs done, is to remove the nut from the bottom clicker assembly, and remove 6 of the 12 shims. It takes about 2 minutes once it's all apart.

The shims are extremely thin, and are what look like a gray washer. All 12 together are only the thickness of a standard washer. Once you remove the nut and start pulling it apart, it becomes obvious. It feels like the nut is slightly crimped, so I'd recommend a drop of blue loctite when putting it back together.

VERY easy to do.

For the rest of the fork job, just watch this video that was posted around a week ago.

The Flight Of the Platypus site that has an excellent photo tutorial on doing the forks on an XR250, which is pretty much the same procedure.

http://www.flightoftheplatypus.net/2007/11/maintaining-your-front-suspension.html

Good Luck!

xr400shimstack.jpg

xr400shimstack1.jpg

xr400shimstack2.jpg

Edited by n2omike

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That's great Mike. Be sure to post what you think of the new found hi speed compression damping in the rough stuff once you get a few rides in.

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That's great Mike. Be sure to post what you think of the new found hi speed compression damping in the rough stuff once you get a few rides in.

That will probably wait until spring.... as it was 11 degrees this morning. lol

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What 'style' or ability tuning would one expect from reducing from 12 to 6 shims? Also, what can be done to the rebound circuit, same?

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What 'style' or ability tuning would one expect from reducing from 12 to 6 shims? Also, what can be done to the rebound circuit, same?

Most people just remove 6 of the 12 shims... and leave it at that.

John Hlebo told me that since I was installing stiffer springs, he would take 3 of the ones removed from the compression stack and put them in the rebound stack.

Problem is, the rebound valving doesn't seem to come apart as easy as the compression. Or, at least I don't know how... and haven't seen a write-up on it... and don't want to take chance at messing it up.

Since people have good luck just removing the 6 from the compression stack when adding stiffer springs, I'm not to worried about it.

Good Luck!

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What 'style' or ability tuning would one expect from reducing from 12 to 6 shims? Also, what can be done to the rebound circuit, same?

My experience with the mod is that it doesn't effect slow speed compression much at all, but does wonders for hi speed hits, allowing the forks to be more reactive and plush to hi speed hits, like rocks, roots and bumps. The rebound circuit continues to work well as is. I've seen no need to mod it.

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What thread size is on the base valve? You guys may be able to use crf150r base valves as an entire replacement. They use a 20mm piston just like those do but they're a modern shimmed piston instead of that reverse bend junk. I have some here that I can measure to compare if you're interested. They're super cheap as well. You can get both complete base valve assemblies for around $60 shipped. A lot cheaper than spending $170 on gold valves for the same thing...assuming they're compatible.

Edited by kan3

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The shim mod works great, over stock We use 2-1/2 wt oil-.43 springs,comp at full soft,rebound out 4-6 clicks.150-170 pound rider (trail bike riding)BTR> Also yes base valve is junk.

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Transplanting XR400R forks onto my CRF230F and did a base valve shim mod for this lighter bike.

Step-by-step with pix here http://bit.ly/2Rgnujo

Thought it might be useful for XR400R owners to add onto this older thread.

Edited by RedMesa

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