02 kx forks

Questions and comments about converting to beefier forks..
muddertrucker
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02 kx forks

Post by muddertrucker »

Last year I did the forks on my KDX. This is my set up: 97 kx 250 forks with stock springs 2 of the bigger shim removed from the comp. valve (leaving 4) and 7 or 10 wt fork oil set at 100mm from top. I weight 175 lbs w/o gear. My problem is I tried my buddys 05 ktm 400 and now whant my suspension to be as plush as his. Riding tha this is like being on on cloud.

I find mine tend to rattle me on slow speed sharp hits and when ever the front wheel lands either from a small jump or a wheelie over an obstacle.

What set up should I got with? Would gold valves do the trick?

I also have a set of stock 02 kx 125 forks that i will begin to try and tune ounce I'm done practicing on the 97's

I recently found that the shim stock in the top clamp was to loose, this also caused a knocking feeling. I added an exta thickness and it seemed to fix the problem but only temporarily as it came back again. I will see if I can have a spacer made up.
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Post by muddertrucker »

Anybody!?
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Indawoods
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Post by Indawoods »

I think you have too much oil in the forks to make them plush....
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Post by muddertrucker »

go with 90mm or lower
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Indawoods
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Post by Indawoods »

More like 110 or 120... it is measured from the top. :wink:
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Post by canyncarvr »

You're not going to fare real well in a set-by-email suspension. There are too many variables involved.

Inda noted a good starting point. 120mm is good.

Removing face shims from the base valve does accomplish something, but it surely is not the answer to every suspension situation. Indeed, it's the answer to few.

What have you done with the mid-valve?

Everything has to work together in order for it to work. Consider this possibility: You 'soften' the base valve to the point it flows enough oil to a too-stiff midvalve too soon and too fast. You might think that further softening of the base valve is going to fix it..it will just make things worse.

Do your forks have bladders in them? I've not heard of any woods rider that liked 'em..and was glad to be rid of 'em:

http://www.kdxrider.net/forums/viewtopi ... ht=bladder

**note** There is a bit more to removing them than just taking out the actual bladder. The RB (Restrictive Barrier) needs to be modified for oil flow.

The best place to start is to know what you have..to start.

If you have bladders...I'd say, 'Get rid of 'em!'

I have my mid-valve stack list at home..but it's something like a stack IdahoCharley has used:

MV
20.1
25.1
23.1
20.1
17.1
12.3

RBD
23.1(4)
16.1
19.1
17.1
14.1
12.1
11.1
Reverse stack follows.


Any particular stack listed isn't meant to be a 'do this' sort of thing. The above is an example of the sort of thing you'll want to work toward in the mid-valve...an object lesson to 'splain a couple of configuration ideas..as in the following:

Note he kept the 'smaller' face shim? This is a bleed. It allows 'some' oil past on initial flow before the volume of oil moving through the piston starts to bend the rest of the stack. A 'bleeder' stack is one 'type' of stack.

Note the 16 in the rebound with larger shims on either side? That constitutes a 'dual stage' stack..a rather gentle one at that.



It's all FM..oil flowing through holes to bend metal washers arranged in a tapered configuration? What kind of baloney is that, anyway?

It's the baloney you have to work with!

Want some cheese with that?

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Post by muddertrucker »

>|<>QBB<
Indawoods wrote:More like 110 or 120... it is measured from the top. :wink:
Yeah... I call that a brain fart, I understood what you were saying but couldn't repeat it.
What have you done with the mid-valve?
Nothing yet, but you have raised a point I was not thinking of (transition)


Soooo... gold valve worth it or not?
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Post by muddertrucker »

Do your forks have bladders in them?
My 97's do not but I'm not sure about my 02's. They have a rubber cover the metal wich contains the mid valve, is that a bladder?

[img][url=http:800:600]http://i85.servimg.com/u/f85/11/15/73/95/pictur10.jpg[/img][/url][/img]
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Post by Indawoods »

For anything you want... someone makes something for it.

They are a quick fix and do replace the midvalve with a check valve setup if you want it I believe. That is old school and works in the woods.

I don't think a one works for all valve is very logical but I have never tried them. I would rather play with my setup and get to know the suspension a little better than throw something in there and wonder why it is not doing what I want it to do.
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Post by Indawoods »

>|QBB<[/url]
muddertrucker wrote:
Do your forks have bladders in them?
My 97's do not but I'm not sure about my 02's. They have a rubber cover the metal wich contains the mid valve, is that a bladder?

[img][url=http:800:600]http://i85.servimg.com/u/f85/11/15/73/95/pictur10.jpg[/img][/url][/img]
Yup...
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Post by canyncarvr »

Gold valves cover only the base valve? Right? That's all I've seen in pictures anyway.

You'd get a decent piston and a bunch of shims anyway.

The mid-valve jwould still need to be addressed.

Transition? You're referring to the split in a two-stage stack? That's called a transition shim(s).

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Post by muddertrucker »

What does the bladder do? It doesn't look like it would serve any purpose.
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Post by Indawoods »

Nothing good! :lol:
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Post by muddertrucker »

I don't think a one works for all valve is very logical but I have never tried them
Well i think they come with a chart to set them according to your weight and riding preferences. I gues they must also come with extra shims.
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Post by canyncarvr »

Yes. Used to be (maybe different now) they sent a config code that allowed you access to a website that gave you 'the setup' for you based on info you supplied when you bought the stuff. Stillll...no mid-valve stuff that I've heard of. The pistons are the same from one setup to the next...but not the valving. That said..it's not like there are 1001 different setups, either.

What do the bladders do?

From a website quoting from an MX-Tech article about bladder forks:

“I want to further clarify some function I didn't specify: there are 2 "charges" or "volume displacers": the rod charge, which is the volume displaced by the 12.5mm cartridge rod entering the cartridge. This charge only displaces volume from the cartridge, and is absorbed by the bladder chamber. The second and most influential volume displacer, is the inner tube charge, which is the inner tube entering the outer tube and displacing volume. The inner tube charge is the charge which is actuating the speed sensitive spring character. This charge forces oil DOWN by the pressure of the oil level chamber, past the restrictive barrier, compressing the bladder chamber.'

From HERE!

I didn't pursue verification to a probably correct extent..the above applies to bladders, yes..but the extent to which that has to do with 'twin chamber' forks (Showas I thought) I don't know..and that term is referenced. The KYB bladder is called a 'clone' of the Showa twin chamber. I do not profess or claim (or have a glimmer of a thought, often) to being knowledgeable about a whole lot of fork stuff.

Note the bleed problems..referred to as inherent and due to design. I'd suggest taking a look at the rebuild procedure on the MX-Tech site. Failure to bleed bladder forks correctly is apparently a known issue.


**edit**

Been thinking...

I don't have bladder forks, I haven't seen a set taken apart. It does seem to me that the above explanation is very good. Consider oil flow from the two 'charges' and where the bladder is..what it 'contains' or holds in. The two charges are considerably different..one being inside, one outside (besides their level/amount/size of influence).

How 'bout it?

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Post by muddertrucker »

**note** There is a bit more to removing them than just taking out the actual bladder. The RB (Restrictive Barrier) needs to be modified for oil flow.
Do your forks have bladders in them? I've not heard of any woods rider that liked 'em..and was glad to be rid of 'em:

So does this mean that what I thought was a good deal on 02 forks was actualy a waste of money? Has anyone here ever just removed the bladders? Are they realy that bad or is it just a bleeding problem?
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Post by canyncarvr »

I can relay only what I've heard over the years.

One suspension guy said that the person responsible for coming up with the bladder idea should be castrated. ..that's the short/printable version of what he said. It had more to do with hanging and becoming dead. They are supposedly responsible for some pretty harsh action. If 'plush' is what you're after, I don't think they go with that.

There's nothing wrong with the forks that some 'tuning' won't take care of.

There are some threads here on removing them. The RB (restrictive barrier) has to be modified when the bladders come out. Try a search for the words 'daisy' and 'petal'. The oil that no longer 'works' with the bladder has to go someplace.

Again...I don't have 'em...didn't have 'em...so I can't say firsthand what the before and after is.

How about some bladder guys chime in here? Scheaket (I think..didn't check that spelling)...IC...bradf (still around?)...

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Post by muddertrucker »

Did a search and found this:

http://www.kdxrider.net/forums/viewtopi ... ight=daisy

I beleive this is absolutely doable (even for me), guess what I'll be doing this week end.

I like the fact that I'm starting to understand some of this stuff, even more because I know it will be even clearer when I get a closer look.
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Post by IdahoCharley »

Just a comment on the 'referenced thread' you found. You will have to remove more material than what is shown in the picture posed by SCHECKAET. Certainly doable at home - I opened ours up removing maybe 1/3 of the total surface of the barrier. Make a four sided or three sided daisy pedal out of the restrictive barrier to allow more oil through. You can look at the area where the restrictive barrier sits and see the area that the oil is forced through. The clover leaf type modified barrier works for our KDX200 which is trail ridden and more recently run in local enduros.

If you want to spend money - Factory connection makes a modified spring spacer for those forks but then you have to also buy some shorter springs so it will cost around $200 for the FC fix.
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Post by canyncarvr »

Re: ' You will have to remove more material than what is shown in the picture posed by SCHECKAET.'

Now THAT is something he was supposed to find out when he READ the thing....

What keeps the RB from bending with all that metal cut out of it?

I understand it's what the spring sits on..so it does see some force, right? Or...is it backed up with something?

Take some good pics before/during/after, mudder. A 'how to' with pitchurs would be very handy!!

Thanks for stoppin' by IC!

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