2008 crf450r fork revalve. need some help

My forks are too harsh on smaller sharp bumps at high speed. I weigh 160# in gear and changed to .43 fork springs. This didn't change the harshness at all but dramatically improved cornering. I then switched to the 1.61kg ICS and decreased outer oil level to 325cc. This helped out nothing, I got high speed instability and some insane hard bottom outs, while still retaining every bit of the harshness. My current setup is .43 springs 400cc honda 5wt, stock ics. compression clicker all the way out, rebound like 7-10 out (I change it around in that range) This seems to work the best, but now it's time to change up the shims. I took the midvalve apart and measured the shims. I'm thinking the rebound shims must be the ones on top, so it looks like this:

mid valve:


thick washer

2 thin washers

rebound shims:

1 11 x .21

1 13 x .11

1 15 x .11

1 17 x .11

1 18 x .11

1 19 x .11

2 20 x .11


compression shims:

6 20 x .11

1 19 x .11



small washers

spring seat

Didn't take apart the basevalve. Should I change the shims in the midvalve or basevalve? I can take apart the basevalve and measure whatever shims are in there also.

The best suspension I ever rode was on the stock 09 yz450 Is there some way to make it like that?

The mid valve spring on the 08 crf needs replacing with 1 from a 2007 it's really stiff I got some stacks on file at home for 08 450 if you pm me I send them to you my rider was 154 lbs we had if I can remember .42 n front and 5.2 n or rear.

pm sent. I was wondering about that spring. It looks like you can change the preload on it by adding or subtracting the washers that go between the collar and the spring seat. Has anyone tried that. Where to you get the 07 one? Honda just sells the whole damper as an assembly.

you cant easily make the fork work with that spring, you need to buy a 07 setup like karl says, any decent proper suspension place like fc or mx tech or smart performance should stock them.

Just take it out, you don't need one there with that little amount of float. And yes you will need to change the base.

Ok. I'm just gonna not run the spring. So I guess the float is the distance the midvalve compression stack can slide on the collar between the piston ports and the washers that sit on the spring seat? Wow I'm learnin a ton about my forks today! So here's the basevalve.











2 x 28

3 x 29

4 x 30

13 x 31

It looks like rebound dampening through the basevalve is controlled by a spring and a single washer. Is that right?

Karl has made a reccomendation for the basevalve stack that I'm going to try out. I don't have to buy any shims to do it.

no that's just a return path , the damping on rebound is done at the back of the midvalve piston , the tapered stack before the nut you removed

You will still have to have the right rear spring rate and sag to make the bike feel right. And the shock has lots of high speed inside. Once you have done your forks if your not happy with your shock we could help you with that to.

Yeah I was just thinkin that the shock might need some attention now. Over a year ago I put a 5.2 spring in it and set race sag at 100 with a static sag of 34. I gotta see how it works at the track this weekend. Thanks for all the help on this guys. I'm pretty excited to see what the difference will be :thumbsup:

Try 105mm when your out at the weekend as well as your 100

Well finally got a chance to ride, and the difference is phenomenal. This is exactly the kind of fork action I was looking for, it's seriosly like I'm riding a different bike. Thanks for all the help on this guys!!!

Glad you was happy with those stacks, now you need to get into your rear shock. Just pm me when your ready.

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