shim stack front suspension
- Thread starter flop2
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Jeff Sexton
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- Sep 7, 2001
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Okay... Hate to sound ignorant, but I am. I've revalved my cartridge forks on my KX250 and the compresion valving has a slow, mid, and high speed shim stack. It sounds like the KDX doesn't. Are all the shims in the compressions stack the same diameter and thickness? I haven't had mine apart yet
matt-itude
Member
- Jul 6, 2004
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in the newer ones yes. I read somewhear here someone saying there older kdx had only half as many shims.
the cartridge forks on the KDX (don't know what year they started, but my 1996 has them) has a real basic shim stack, 10 shims all the same thickness and diameter. Take two away and you have a 20% reduction in resistance to oil flow, which makes the fork handle a lot better.
If you want to tune it more finely than 10% increments and/or you want progressive damping, you'll want to get an aftermarket shim stack such as Gold Valve.
Cheers,
Andrew
If you want to tune it more finely than 10% increments and/or you want progressive damping, you'll want to get an aftermarket shim stack such as Gold Valve.
Cheers,
Andrew
Jeff Sexton
~SPONSOR~
- Sep 7, 2001
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Well that clears things up nicely! I forgot to mention when I revalved my KX250, I was putting in Gold Valves at the same time. I guess the three stage approach is unique to the after market suppliers as I seem to recall the stock valving was much simpler.
I can't wait to try this. I put stiffer springs in to reduce/eliminate the diving feeling on steep downhills and hard braking, but it still didn't feel quite right. Tried adjusting clickers out for softer feel but just couldn't quite get it where it needed to be. This sounds like the perfect solution and CHEAP!!!
You guys are a credit to the dirt biking world!
I can't wait to try this. I put stiffer springs in to reduce/eliminate the diving feeling on steep downhills and hard braking, but it still didn't feel quite right. Tried adjusting clickers out for softer feel but just couldn't quite get it where it needed to be. This sounds like the perfect solution and CHEAP!!!
You guys are a credit to the dirt biking world!
No worries mate, glad you're trying it!
I was in the same situation as you, I had .41 XR400 springs in but I was still getting beaten up on rocks. I had wound my compression clickers all the way out as soft as they would go and it made no difference at all. Now, after removing those shims, I have the compression clickers in a more central position where I have a lot more fine-tuning potential.
Dare I say it, my KDX even handles the MX track now - when I land from a big jump the suspension is handling it nicely and I don't feel as if I'm about to get thrown into next week !!
Cheers,
Andrew
I was in the same situation as you, I had .41 XR400 springs in but I was still getting beaten up on rocks. I had wound my compression clickers all the way out as soft as they would go and it made no difference at all. Now, after removing those shims, I have the compression clickers in a more central position where I have a lot more fine-tuning potential.
Dare I say it, my KDX even handles the MX track now - when I land from a big jump the suspension is handling it nicely and I don't feel as if I'm about to get thrown into next week !!
Cheers,
Andrew
i love drn because of stuff like this. i have a friend who bought a very nice kdx 1994 with 946miles on it. its in great shape but boy does it suck on the rocky sharp edged stuff. it also has a nasty habit of the front end knifing in turns. i ride a 00 cr250 in the woods and thought the kdx would be a couch.....i hated the kdx front end. granted, my cr had similar problems until high speed compression valving was reduced. i told my buddy that i suspected too much high speed compression and you guys have confirmed it.
his 94 has the non adjustable upside down forks. where is the high speed compression stack on these particular forks? thanks in advance for the replies
his 94 has the non adjustable upside down forks. where is the high speed compression stack on these particular forks? thanks in advance for the replies
93' - 94' Have USD Forks
Both the 93 and 94 have USD cartridge style forks where the compression can be adjusted using the clicker located at the bottom of each fork (there is a rubber plug covering the clicker). The cartridge can be removed same as the newer forks and the shim stack can be modified. The primary difference between these forks and the newer forks is there are less shims on these forks and they are not all the same thickness. As I posted earlier in this thread, I removed the thinnest shim from a stack of 4 and reduced the compression by 21%, very similar to removing 2 shims from the newer forks which reduces the compression damping by 20%.
Bottom line - the results were excellent and should be a "Must do" along with changing out the springs!!
Both the 93 and 94 have USD cartridge style forks where the compression can be adjusted using the clicker located at the bottom of each fork (there is a rubber plug covering the clicker). The cartridge can be removed same as the newer forks and the shim stack can be modified. The primary difference between these forks and the newer forks is there are less shims on these forks and they are not all the same thickness. As I posted earlier in this thread, I removed the thinnest shim from a stack of 4 and reduced the compression by 21%, very similar to removing 2 shims from the newer forks which reduces the compression damping by 20%.
Bottom line - the results were excellent and should be a "Must do" along with changing out the springs!!
thanks. the only bike ive done the high speed compression revalve on was a showa equipped cr and the compression cartridge is in the top. i knew the upside down forks were only a couple of yrs but i thought it was 94-95. we will go ahead and give it a whirl. its amazing what those little disks do.
Wow, am I glad I came across this thread!!! I'm just getting into setting up my "new" 97 KDX. My 91 forks had been reworked with RaceTech gold valves, cartridge emulators and springs and worked well. When I looked into setting up my 97 forks, I discovered the price has gone way up for that kind of job. It sounds like the correct springs and this modification of the stock shim stack may just get the job done!
Flop2, QLD_KDX and Canadian Dave,
This sounds like an excellent addition to the suspension modification page on the main site. Flop2, you mentioned that you had taken pictures of the procedure, would you be willing to post them?
I'm definitely going to give this a try!
Thanks a lot,
Rob
Flop2, QLD_KDX and Canadian Dave,
This sounds like an excellent addition to the suspension modification page on the main site. Flop2, you mentioned that you had taken pictures of the procedure, would you be willing to post them?
I'm definitely going to give this a try!
Thanks a lot,
Rob
Jeff Sexton
~SPONSOR~
- Sep 7, 2001
- 130
- 0
robl...
I just did this on my 04 KDX200. If you have an air impact wrench and a 14mm Allen socket, you can do it without any special tools. In fact, unless you need to service the fork, you know - clean the internal parts and change fork oil, you can do this mod without even disassembling the fork. Just take the forks off the bike. Turn the fork upside down and compress the fork as much as possible (my work bench is just the right hight to allow compressing the fork about 5" and slip the axle under it). The impact wrench will allow you to remove the compression valve without any special cartridge holding tool.
The nut that holds everything together is staked on. File the aluminum "bolt" flush with the steel nut and remove the nut. There's a four fingered "holder" that encloses the shim stack. Carefully pry the holder and shim stack off the valve body. Inside there are 10 identical shims and some other stuff. Remove two of the shims and clean everything with brake cleaner to remove any filings. Reassemble in reverse order. Be careful when putting the nut back on the valve body. Use a half drop of red locktite and don't overtighten. Just snug it up or you'll risk stripping the threads on the aluminum valve body.
Good luck! I hope you like the results as much as I do. Thanks to the guys that make this forum one of the very best!
I just did this on my 04 KDX200. If you have an air impact wrench and a 14mm Allen socket, you can do it without any special tools. In fact, unless you need to service the fork, you know - clean the internal parts and change fork oil, you can do this mod without even disassembling the fork. Just take the forks off the bike. Turn the fork upside down and compress the fork as much as possible (my work bench is just the right hight to allow compressing the fork about 5" and slip the axle under it). The impact wrench will allow you to remove the compression valve without any special cartridge holding tool.
The nut that holds everything together is staked on. File the aluminum "bolt" flush with the steel nut and remove the nut. There's a four fingered "holder" that encloses the shim stack. Carefully pry the holder and shim stack off the valve body. Inside there are 10 identical shims and some other stuff. Remove two of the shims and clean everything with brake cleaner to remove any filings. Reassemble in reverse order. Be careful when putting the nut back on the valve body. Use a half drop of red locktite and don't overtighten. Just snug it up or you'll risk stripping the threads on the aluminum valve body.
Good luck! I hope you like the results as much as I do. Thanks to the guys that make this forum one of the very best!
Jeff Sexton
~SPONSOR~
- Sep 7, 2001
- 130
- 0
Hey you know that part about "you don't have to completely disassemble the fork"? Well it's true, but I would recommend that you do it anyway because 1) they probably need it, and 2) the upper guide bushings seem to wear out pretty quick.
When I did the forks on my '04, I discovered the guide bushings were shot after just 1 season. There's a separate post on this subject, but apparently it's a pretty common problem.
When I did the forks on my '04, I discovered the guide bushings were shot after just 1 season. There's a separate post on this subject, but apparently it's a pretty common problem.
notenuftoys
Member
- Sep 3, 2004
- 101
- 0
Alright, put me on the list for trying this out also. After this weekend riding, I've concluded that my forks aren't set up right. I'm not an expert on suspension, but they're just too stiff when getting into corners. They want to push right through (like understeer in a car). I was thinking it might be too much preload, but after reading through this thread, this sounds like it might be part of the problem. I've got to find time before the race at the end of the month.
If it understeer in corners or turns I heard that one shall make rebound slower. If rebound is fast it will keep the fron up and it is harder to push it down to make the turn easier?
A slower rebound will let the bike tip forward a bit and stay there trough the bumps during the bend.
In KDX a 7w or 10w fork oil will make rebound slower (if 5w is present).
A slower rebound will let the bike tip forward a bit and stay there trough the bumps during the bend.
In KDX a 7w or 10w fork oil will make rebound slower (if 5w is present).
chris_psmith
Member
- Mar 12, 2006
- 18
- 0
Well I have the forks from a 99 kdx220 in bits on the kitchen table, no sign of a shim stack - nut - cup - spring - larger cup - toothed washer - spring washer - solid bush (that the toothed washer is fixed to) - adjuster body.
Am i missing something or is it not fitted to this model?
Am i missing something or is it not fitted to this model?
Cartridge @ Bottom
The cartridge you are looking for is at the bottom of the forks. The internal hexagonal plug at the bottom of the fork legs unscrews but you've got to hold the inner tube or take them out with an impact driver while the fork is still assembled. There is a small 10mm nut on the end that is inside the fork. This nut holds the shim stack on the end of the cartridge and the shims are only 12mm in diameter and are very thin. The entire stack is only about couple millimeters thick.
Good luck with this your 220 has them but all these parts are very small and if you have separated the tubes you may allready have the cartridge out.
The cartridge you are looking for is at the bottom of the forks. The internal hexagonal plug at the bottom of the fork legs unscrews but you've got to hold the inner tube or take them out with an impact driver while the fork is still assembled. There is a small 10mm nut on the end that is inside the fork. This nut holds the shim stack on the end of the cartridge and the shims are only 12mm in diameter and are very thin. The entire stack is only about couple millimeters thick.
Good luck with this your 220 has them but all these parts are very small and if you have separated the tubes you may allready have the cartridge out.
chris_psmith
Member
- Mar 12, 2006
- 18
- 0
Thanks, I had them stripped down and the parts I described were on the bottom adjuster, could see no sign of any shim stack, re-assembled them last night. Where in the order I listed above should the shim stack be? Bottom of the larger cup washer or under the spring washer?
They are -spring washer - shims - solid bush!
You have to take the things apart to se (understand) that this is in reality a set of washers !
Take two away - I did, and it made a different.
I am usin .42 springs and am 75kg running on different grounds (rather slow...)
You have to take the things apart to se (understand) that this is in reality a set of washers !
Take two away - I did, and it made a different.
I am usin .42 springs and am 75kg running on different grounds (rather slow...)
Need help sorting my suspension out
Hiya everyone
ive got usd suspension on my pit bike, its a Evo 150cc.
i needed to put sum suspension fluid in, so i did that but my suspension as gone really hard.
it bearly goes down :pissed:
im just wondering how i sort it out, as i have got no idead about suspension.
im just wondering if u can help me? please!
Hiya everyone
ive got usd suspension on my pit bike, its a Evo 150cc.
i needed to put sum suspension fluid in, so i did that but my suspension as gone really hard.
it bearly goes down :pissed:
im just wondering how i sort it out, as i have got no idead about suspension.
im just wondering if u can help me? please!
adam04god said:
Hey Adam,
This forum is pretty much dedicated to the Kawasaki KDX, so it's unlikely you'll get bike-specific info here- it might be a good idea to try and find a forum that is especially for your Evo.
That said, what you're describing could be the result of you changing the weight of the fork fluid you used (heavier fluid will slow the action) and/or putting more in than you were supposed to. The owners manual may, and the service manual will have recommendations on both of those- what weight, and how much to use.
Good luck.
