KDXRIDER.NET

Hello, all. I'm in the process of disassembling my 99 KX125 forks to get them set up for my 98 KDX200. I've read a lot about white plastic rings and bladders that should be removed, but I can't seem to find them anywhere in the forks. I have a feeling that they have been modified already and possibly those parts removed. Does anyone have any links to some resources that might show images of what I'm looking for as well as a good guide for tearing these forks down? I have seem numerous videos of similar forks, but not sure if they are the ones I have. I have also done a lot of searching on the forums, but can't seem to find any images to point me in the right place. Thanks in advance for any pointers!

Are you able to post some pictures?

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I worked on a friend's 2000 KX125 forks to install them on his 1997 KDX220R years ago, so I am familiar with the internals.

You should read up on the o-ring mod on the midvalve.

Here is a picture of my 2000 KX forks taken apart. The black tube you see is the bladder and the parts below it is everything related to removing the bladder.

This video shows the process of servicing the forks but has nothing to do with the bladders. The forks he's working on don't have bladders but the process of breaking them down for a seal change helped me out a lot. I was worried about doing it until I watched that and it ended up being really easy once I had the 14mm Allen socket and applied downward pressure with the axle.

One need only remove the white ring to disable the bladder.

Removing it changes the oil level requirements. Either way is fine.

I have not seen the inside of 99's.

Thanks so much for the images, video and advice everyone. I will definitely research the mid valve modification. I will post some pictures below of the internals of my fork. I definitely don't think there is a bladder unless it has already been removed, or the 99 doesn't have one, or I purchased a different year fork from a major online auction site. Hmm. I kind of believe that it may have been worked on previously because I didn't have to file down the peens on the compression valve in order to remove the nut and it seems like there aren't as many shims in the stack as I've seen/read about on other posts. I have only opened up one tube so far so I can't speak for the other one yet. Thoughts?

I did some research. 1999 did not come with bladders. That cartridge would have a place for the circlip to hold the bladder. It would be down at the bottom, toward the holes.

Those have the 1999 fork lug (axle holder portion). 1998 on back to whenever had the plate and four studs / nuts.

Replace the o-ring with a spring. I think I bought them from Race Tech when I did my buddy's 2000 KX125 forks.

From Motocross Action Magazine's website:

2000 KX125 / KX250 cartridge and bladder

Thanks for the picture of the bladder and the tip on the midvalve. I'm starting to go cross-eyed trying to find some information other than "change the midvalve o-ring." I've tried google, searching this forum, thumpertalk, etc. I've also tried looking on multiple suspension websites. I can't seem to find the springs to use as a replacement for the o-ring. I did find a good post with pictures about removing and modifying the midvalve though. Any chance that someone has an idea of where I might find the springs? Maybe call race tech and see if they still have them and they just don't have them listed on the website?

KDXGarage wrote: 04:02 pm Jan 23 2019 SNIP

Replace the o-ring with a spring. I think I bought them from Race Tech when I did my buddy's 2000 KX125 forks.

Yes. Call RT. That's what I did. I think it even mentioned it in their 2830 kit instructions.

KDX20098 wrote: 03:21 pm Jan 23 2019 Thanks so much for the images, video and advice everyone. I will definitely research the mid valve modification. I will post some pictures below of the internals of my fork. I definitely don't think there is a bladder unless it has already been removed, or the 99 doesn't have one, or I purchased a different year fork from a major online auction site. Hmm. I kind of believe that it may have been worked on previously because I didn't have to file down the peens on the compression valve in order to remove the nut and it seems like there aren't as many shims in the stack as I've seen/read about on other posts. I have only opened up one tube so far so I can't speak for the other one yet. Thoughts?

I had a shop revalve my KX250 forks so I'm not familiar with the valve stacks. Is that the compression stack that we're looking at? If it is, the high speed compression after that small crossover shim only has one shim then maybe a base washer. I bet that would be really harsh on the trail.

FOUND

IT!

Finally after much searching: from elsewhere

(On the Gold Valve website it has specific instructions for my bike and kit. It says:

"Replace Mid-Valve o-ring with check spring provided. ...")

ericr,
That is indeed what you are looking at. Thanks for the input on that. I'm still researching shim stacks and learning a little about how I want them set up to start with.

KDXGarage,
Thanks for looking into that further and the tip on calling RT. I just got off the phone with them and have the check springs on the way! They are only $2.29 each if anyone is curious. Moving right along!

Sweet!!

Springs arrived yesterday. RT ships pretty quickly and as It turns out the shim stack I posted is not accurate. Some more shims were stuck together. I am in the process of going through everything and making adjustments on one fork leg. My plan is to post pictures of the process in the suspension forum once I go to do the second. I figure this might be helpful for others if they decide to tackle a project like this which I would encourage. It's always nice knowing the bones of these things in order to promote a better understanding. Stay tuned!

I don't know where you are on disassembly, but try to do one leg at a time, using the second one as a reference.

I will stay tuned!

KDXGarage wrote: 06:35 pm Jan 29 2019 I don't know where you are on disassembly, but try to do one leg at a time, using the second one as a reference.

I will stay tuned!

Good tip. I am doing just that. I know the limits of my short term memory.