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I noticed my son's shock on his kdx 220 is to stiff on rocks, roots, sharp impacts. I thought these were suppose to be trail bike. What give? I do my own suspension work. He are the shim changes I am to my son's rear shims. Before I decided to revalve the shock. Sprong the bike for my sons weight. installed a 4.7 rear spring and serviced the shock. Still don't like it. The high speed comp is to stiff. Below is the stock shim setting and the changes I made. I am very happy with the results.
Starting from the top
Nut
Reb. - left it stock
21.3
24.3
26.3
28.3
30.3
32.3
34.3
24.1
7-34.2
piston
comp. stack
7-32.2 - this is the low speed stack
30.1 - crossover shims
25.1 - crossover shims
36.3 - beginning of high speed stack
34.3
32.3
30.3
28.3
25.3
22.3
19.3 - end of high speed stack. also know as the clamp shim. Very important. The smaller diameter it is the easier the rest of the shim can bend around it.


New comp stack
piston
7-38.2
25.1
34.3
32.3
30.3
28.3
25.3
22.3
19.3
17.3 New clamp
30.1 Removed from up top.
36.3 removed from up top.

done.

No questions, comments, or suggestions? I am happy to help people learn how to re valve there own sups. There is no reason to pay big money for it.

What do those numbers mean? Thickness?

Ex: 7-38.2

7 shims at .2mm thick x 38mm wide. I picked up the lingo from the suspension companies.

Any other questions I will be happy to help. I love dirt bikes. Have ridden them all my life. I am regular CR500rider.net and TT honda two stroke section.
Since I got my son a kdx a few months ago. I found this site and noticed lack of suspension talk over here. Don't get me wrong. There is alot of great info here. Good site. I though I would try to help. After I did my own RD of course.
steve

Hey Steve - where did you get the shims. I'd like to do the same thing to my stock shock. Obviously I need a heavier spring than your son.

I've revalved my own forks a few times but never a shock.

How was the stock piston? Looked like it would flow enough to not need a goldvalve kit?

Did you find the shock more responsive to clicker changes with the changes to the compression stack?

TIA

That is one weird shock. The stock compression stack is great for most of us - I have never had an issue with the rear shocks on any of my kdx's , through my racing years and beyond. The front is another story....

I made this one from a 30.3 shim. It is not hard to do if you are patien and have some tools. But it is easier to order them. Race tech and mx tech sell shims for about a $1 each
17.3 New clamp

These two were removed from up top.
30.1 Removed from up top.
36.3 removed from up top.

My kdx kicked harder then my stock 03 cr125 and 05 cr250 did on rocks and roots. Granted the cr's have come alone way in the susp. department. I remember my 95 cr 250 kicked more then the kdx did stock. I know the valving in the kdx shock was stock, because the ping on top of the shaft was still there. The piston design looks good. I don't think there are any oil flow problems. Just to stiff on the high speed shim stack. Next time you service your shock try the changes I made. I think you will like it. Just be carful grinding the ping of the shaft. It also holds the rebound needle in place. If you grind the ping off straight across then the rebound parts will come out. NOT GOOD.

Is there an illustration somewhere that shows the fork assembly you are describing and perhaps also shows the changes you made? The OEM parts pages don't show the individual shims & etc., at least that I can make out.

It's great that you're doing your own revalving...I do it also. Good info all around..
Thanks!

What oil do you use in your rear shock, and why?

I have tried most brands. But I keep coming back to Maxima susp oil. I use 5 wt front and rear.

Which one?

Here is a pic on the forks apart. It is not my pic.
The comp valve is mounted to the pic of al. in the bottom left of the pic. Its vavle is next to it on the right.
The rebound valve attachs to the end of the long skinny shaft. The valve is on the bottom right in the pic.
The rebound only has three shims. If you add more it rebounds slower
The comp has 10 (if I remember my notes correctly). If you take 3 from the comp stack and install them in the rebound. The comp will become plusher and the rebound slower. this helped my forks greatly. http://www.google.com/imgres?q=pic+of+k ... 0,s:0,i:90

This is what I have been getting from my dealer her in town. I have yet to try there highend susp fuild.
http://www.maximausa.com/shopping/index ... ucts_id=45
I use it for both my shock and forks.

Maxima oils are good, but that oil is not suitable for use in a shock. The VI is too low, and it won't stand up to the temps and abuse in a shock. Not to criticize what you're doing, but you really should take the time to learn about suspension fluid before you do any more revalving. The oil in your suspension is really the most important component aside from the springs, and should be addressed first. Your shock harshness could have been cured with a change in oil.

thanks for the info. I don't pretend to know every thing. Those that do are wrong. I will do some sups. oil research. I have used 3 weight shock oil in the past. As for my 98 kdx 220 shock being harsh. I don't think it would have made enough of a difference to fix the harshness of this shock. As I said before it was more more harsh than all of my cr bikes. And this is suppose to be a trail bike.

This is an excellent resource. Peter really knows what he is talking about.

http://www.peterverdone.com/archive/lowspeed.htm

Read it, then look at the different oil's true viscosity. Pretty interesting stuff.
I've used this info to smooth out some really harsh suspension. I like that redline JLW for my shocks.

Steve_K wrote:I noticed my son's shock on his kdx 220 is to stiff on rocks, roots, sharp impacts. I thought these were suppose to be trail bike. What give? I do my own suspension work. He are the shim changes I am to my son's rear shims. Before I decided to revalve the shock. Sprong the bike for my sons weight. installed a 4.7 rear spring and serviced the shock. Still don't like it. The high speed comp is to stiff. Below is the stock shim setting and the changes I made. I am very happy with the results.
Starting from the top
Nut
Reb. - left it stock
21.3
24.3
26.3
28.3
30.3
32.3
34.3
24.1
7-34.2
piston
comp. stack
7-32.2 - this is the low speed stack
30.1 - crossover shims
25.1 - crossover shims
36.3 - beginning of high speed stack
34.3
32.3
30.3
28.3
25.3
22.3
19.3 - end of high speed stack. also know as the clamp shim. Very important. The smaller diameter it is the easier the rest of the shim can bend around it.


New comp stack
piston
7-38.2
25.1
34.3
32.3
30.3
28.3
25.3
22.3
19.3
17.3 New clamp
30.1 Removed from up top.
36.3 removed from up top.

done.

Sorry to resurrect such an old thread, but I was going to service my shocks and thought that now would be the time to do a bit of work on the valve stack.

I called Racetech to order the 17.3 clamp shim, but they don't make shims that size. For 0.30 thick shims, the closest they have is 20 OD. For 0.25 thick shims, they have them down to 18. Any suggestions on what I should use?

Here's Racetech's list of shims. Our KYB 44mm shock uses 12mm ID shims. http://www.racetech.com/HTML_FILES/sh-shim.html

MX Tech has them. I think that's where I ordered from the last time.

What worked for him might not work for you.

What is your weight in riding gear?

Skill level?

Terrain?

Many factors.

EDIT: When I said MX Tech has them, I meant shims in general.

I'm currently in the middle of a revalve on a CRF230 and have done both end of my 650R. I bought single shims from SDI. Race tech only listed 10 packs but maybe would single out if you called them. Get an extra (lock) nut for the top of the shim stack while your at it.