KDXRIDER.NET

Hi everyone,

I recently installed a 1990 kx500 fork on my kdx200 but its to hard for trail ridin', so I need some tips to make it soak up the small stuff a bit better, I'm thinking of revalving but how ? I've never done something that and letting it do by a company is a bit to expensive for my taste.
I'm also thinking about playing with the oil level but how much goes in stock and how much would be best for trails ?

Any extra tips would be apreciated.

I'd look at a couple of things first.

You might try a 5 or 2.5 wt fork oil
make sure the lower pinch bolts are not too tight and that the forks are aligned
front tire pressure
Clicker adjustments. "Softer" is not really softer. It is less damping which may not be what you want.
Spring preload - not too much and not too little

I'd look over at some of the KX500 sites for what others have found.

Thanks,

I've found that the oil level range is 70-120mm.. But I can't find how and where I'm suposed to measure that..

I asume thats on the top of the leg with the spring out, but compressed or extended?

Sorry for the so many questions :$ this is my fist inverted fork and the only thing i've done to conventional forks are replacing the seals and filling it up with factory specification amount of oil.

Take a look at what many folks have done to MX fork compression valve stacks in the USD section here. Basically, you will probably want to remove about half of the shims. Most guys only run 4 or so of the 24mm dia. Also make sure the spring rate isn't too stiff, depending on your weight/skill. The stock KX500 springs, as I recall, are 40's so they may be a bit harsh unless you are an aggressive rider or weigh more than 170 lbs.
The shims are held in place with a nut on an aluminum treaded rod. carefully file off the peened end before you remove the nut - when re-assembling make sure the threads are clean and use locktite. Don't over-tighten the aluminum threads!

A tip; to take the compression stacks out, pull off the gas tank, squeeze off the tranny vent hose with vise-grips, wrap some rags around the handlebar controls, flip the bike upside down....and spin those babies right out (modify one side at a time leaving the other in place) with an impact wrench.

For oil level, most off-road USD's work better with less oil, I usually run 120mm to get full travel more easily - the measurement is taken with the forks completely compressed.

Thanks!

I've adjusted the oil level (120mm) and it feels a bit better, didn't had a chance to ride it tho (its 23:01 at the moment, neighbours wouldn't appreciate it )

A thing that I found a bit strange is that I only could find one shim?

I think I need to take a look at a exploded view for this one,

Thanks for the tips!

The shims are VERY thin. Like thinner than a piece of paper most of em. Most forks have 20-25 shims

look into getting the right weight spring.

I farted around with valve stacks and shims with my KX450F fork, but it was the softer springs that made a world of difference.

heckler wrote:look into getting the right weight spring.

I farted around with valve stacks and shims with my KX450F fork, but it was the softer springs that made a world of difference.

I don't know what springs are in there now, not the stock ones thats for sure (Reiger suspension) but I don't wanna buy springs and then I discover that they are the same or heavier :s

I'm around 215lbs (98kg) and 193cm tall, not a real fast rider but not slow eather.
I mostly ride woods and (wet) bumpy sand.
What would you recommend ?
Also any ideas about the front tire for this kind of terrain? It must be a road legal tire because my bike has a licence plate and I don't wanna get pulled over for a tire (€140 - $180)

They will NEVER check your tires if you get pulled over.

You could rig up a spring weight tester to get a pretty accurate number for your existing springs.

I think I would spend a bit more time with clickers and oil weight (not height). You might also look to the rear supension. Changing forks can have unexpected results. Depending on the forks and fork springs you could be riding high or low in the front. Adjusting the rear might put things back in balance and make the front work better.

I think you might need to visit a local shop for a front tire selection. They should be more knowledgable about what is appropriate on the streets and trails of Droegeham.

Frysk wrote:
A thing that I found a bit strange is that I only could find one shim?

!

as old as those forks are, I'm surprised you found any shims

Slick_Nick wrote:They will NEVER check your tires if you get pulled over.

Never been to Holland I hear ?

KarlP wrote:You could rig up a spring weight tester to get a pretty accurate number for your existing springs.

I think I would spend a bit more time with clickers and oil weight (not height). You might also look to the rear supension. Changing forks can have unexpected results. Depending on the forks and fork springs you could be riding high or low in the front. Adjusting the rear might put things back in balance and make the front work better.

I think you might need to visit a local shop for a front tire selection. They should be more knowledgable about what is appropriate on the streets and trails of Droegeham.

Thats not a bad idea, but the bike is quite good in balance at the moment (at least 20times better than with the previous fork)
only thing now is that it absorbs the small bumps (branches, small holes etc) a bit better

Mr. Wibbens wrote:

Frysk wrote:
A thing that I found a bit strange is that I only could find one shim?

!

as old as those forks are, I'm surprised you found any shims

Yeah that's what I thought.. I think the thing I've found isn't even a shim.