KDXRIDER.NET

It is my understanding after countless hours of reading that to make your KYB USD forks plush for the woods that you should reduce the height of the shim stack and flatten it out, more wide than high.
Also, the locking washer has a lot to do with it also, if this washer is removed or replaced with a thinner narrower washer... it will make the forks more plush also.

Oil weight will add some resistance initially but oil height adds bottoming resistance.

What is the existent stack? ...should say YOUR existing stack. Who knows if it's been changed. I haven't looked a whole lot (some) but I haven't found an OEM KX250 stack listing that I trust is OEM.

Which locking washer are you referring to? The one that eliminates the bladder action? There is a washer somewhere in there that, when either removed and replaced with a different washer, or has holes drilled in it will eliminate the midvalve spike that the KYBs are known for.

I found an OEM Showa stack awhile back that was interesting. All the same thickness, varying only by 1mm each 'step'. That is what I would call more wide than high.

Keep in mind that all I've done regarding shims/stacks is take them apart, change 'em around (just 'cuz) and then change them back to what they were from the gitgo (they having already been revalved by two different tuners) cuz I liked what I started out with better.

C'mon, Inda. You have to relegate your post to the category of 'teaser'. What stack configs? From where did you get that? Says who?

My reading says that KX oil level for the woods is probably going to be a good be lower (less oil) than any KX 'spec' you will read...that spec being well, for a KX! A lower oil level will get you quite a bit softer reaction over small stuff cuz the 'air shock' is larger.

A BTW...the last tuner that worked on my KDX forks recommended 120mm. Being the argumentative naysayer that I am...I tried 115, then changed to 120. Lo and behold...I liked 120mm quite a lot better.

I'm NOT sure about this...but I think I've read 120mm for the KX woods setup, too.

We need a separate board for all this KX stuff!

Another BTW...what are you USD'ers using for torque specs for the top/bottom clamps? Still 18/14ft/lbs bottom/top maybe? (I wrote those numbers on my clamps cuz I got tired of looking 'em up.)

I have yet to take the valve OUT of my ProPilot forks, yet. I still haven't gotten my wheel, still don't have an axle, not sure what to do about brakes.

AND...seeing as I've already hijacked this thread 38 different ways....it occurs to me that the underhang of the KDX forks that I curse at readily has for certain saved my front rotor more than a few times!

Sumpthin' else to wonder about............

Of course it's a teaser!
It is meant to start a discussion about the subject. The "lock" washer is the washer right before the nut. The "stock" stack uses something like 3-6 of the largest washers.... several of them being taken out of the mix will result in a much plusher suspension. This allows the washers to flex a lot more. You must have enough shims to be able to lock the stack down securely though and sometime getting a good configuration and being able to still lock it down can be a challenge. A "tall" stack is going to be more harsh than a "short" stack and a progressively wider stack is going to be more plush than a narrower one. Leave the midvalve in place and you can tune around it... let the midvalve do it's job.... it's a good thing.

A higher (instead of low) oil level prevents bottoming.... if it feels harsh then you should revalve until it's right.... you CAN get there!

Torque specs: Yes... I'm using the KDX specs since I don't have the KX specs. But, I have also read that if you torque the lowers too much it causes stiction. I still need to research the specs more... or get a manual.

Of course, if your forks have already been revalved, I think you should try them first before changing anything... Who knows... maybe the guy who was using your new forks name was TralTamr... your alter-ego!

canyncarvr wrote:....it occurs to me that the underhang of the KDX forks that I curse at readily has for certain saved my front rotor more than a few times!

Sumpthin' else to wonder about............

No kidding. ironically enough, my fork leg on the brake side is all dinged up, and the one on the other side looks almost new. Seems like the dirt Gods know what side to put the ammo on.

That's funny... I always got logs wedged in between them!

Please read....

http://ericgorr.com/techarticles/susweb.html

Well....so what's the stack you gots?

Dangit if I can't find that Showa list I saw last week. I think it's in the thread you linked to in a thread you opened, Inda. Gotta go look summore.

PuhLEEZe post yours!

You know... I haven't looked. I am going to try them first to get a good feel of the action before I tear them apart. That way I can tell what I am changing. If you look in my gallery.. my bike is down to the frame at the moment. When I do tear the forks down, I will make all my measurements and start tuning.

I will look for the stock stack on a 03 KYB USD, I have it at work but not at home so it will proly be tomorrow before I can post it.

P.S... Who cares about SHOWA???

Well, besides being completely different and therefore not likely the same, I think the general agreement is that Showa is considerably better than Kayaba in the fork department.

The only Showas I've ridden are on a CRF250-X. They are wonderful. Out of the box!

I've GOTTA take the valve outt'a those forks sitting on my dining room table.

I'll get a round tuit...pretty quick.

Here is a site that gives great information on suspension I found. You gotta register and all areas aren't free... but a great site none the less....

http://www.suspensionnetwork.com/

I am glad to see that you all are reading up a storm. Maybe you guys could post what year KX forks you have since they may be very different in terms of valving and pieces/parts.

To start you off, canyncarvr, 24.1x8

YOU'RE WELCOME, now keep searching, reading, searching, reading, repeat as needed.

Here's a link to my stock shim stack... of course you will have to register on the site mentioned above first...

http://www.suspensionnetwork.com/shimpr ... =View+Fork

IndaWoods, total visits 3

One thing I can tell you is... I can make mine a lot more plush.... there are 7 24.15 shims stacked together... remove 4 and it get's a lot more plush and I retain the midvalve that has .57 lift... so it IS doing something!

Who said that was me? All the info I have read comes from a lot of different places.... Eric Gorr , Jeremy Wilkey etc... This site is relatively new... within the last few months from what I can tell...

The more places you can get information from, the better. It used to be http://www.shimprogram.com. It has been around for quite a while, actually.

Sorry, folks. It's stuff like this that makes no sense to me whatsoever.

I understand the basics of stacks and how they work ok...but putting eight of them together all the same? What kind of tapering, progressively 'more' thing is THAT?

Looking at the various graphs and such on the shimprogram site, it seems a dual stage stack is going to do better at softer/slow than a single stage stack would.

I note the comments on the stock valving page say, 'Progressive springs too soft at top of stroke' even with all eight of those 24.4s together. I like the sound of that. If it's too soft for the track, it's still probably too stiff for the woods!

Inda..the '..57 lift' means what?

And how about the 11.10.K5 part? (shown on the 'stock' valving list for a '99 KX250)

Yes, I just read through the whole primer! Sounds real good. Looking for modified stacks entered for a KX250 used in the woods?

Nothing. Poop!

That is a very well written site! I've been through it before. Ha! If I paid my $90 to find the same (none) info for a kx-woods-250, THAT would be a bummer!

BTW...why a 'conversion chart'? If you mean 24(mm outside diameter) X .1(mm thick), why not just SAY 24.1?

Why 24.4 with a conversion chart telling you that '4'=.1? Looking at the list I printed off for a '99 KX250, I DO note that there is no confusion due to duplicaton. All of the 'different' numbers used 'convert' to different thicknesses:
4=.1
6=.15
8=.2
10=.25
12=.3

...and then someone like INDA goes and uses the actual thickness number..just trying to confuse the issue I guess. But then...they do the same thing themselves in different places on their site.

AND...they 'assume' inside diameter to be the same, I guess. I have read, 'Inside diameter doesn't matter.' Really? Then why is it that people that know (like Jeremy from MX-Tech) do NOT use all the same inside diameter shims? Methinks there IS a reason they aren't the same...that it DOES matter.

Well? Huh? Howabout THAT?

...this sort of stuff makes my head hurt.

canyncarvr wrote:Inda..the '..57 lift' means what?

Meaning that it is lifting the valve instead of hitting a wall and dispersing, it moves and taking some of the action away from the moving fluid. That's my take on it anyway...

I think you have to take it all in and figure it out... that's what I'm trying to do... I get a better understanding of it every day and by the time I'm ready to revalve... I should be able to make a difference in the right areas to come out with a nice setup. That's the plan anyway....

Stack on the '99KX250 ProPilot forks I gots:

24.18 x 4
22.18
20.18
17.18
16.18
11.18 x 2
....
17.5 x 2

Don't know how sloppy they get with shim measurement. Most of mine are .007" which relates to the .18mm number. That isn't a 'standard' shim thickness. Most are 8mm inside. Note #s 9&10: These are only .060" (1.5mm) wide!

Sure not like the oem stack! Guess that's the point............