The KLX is a great little bike. I hate to see it's performance degraded by such doggy forks.

I was able to overcome this by throwing on a cheap set of KX forks, revalving and adding subtanks. It's a stunning front end - no deflection and soaks up large and small. Best I've ridden in our rocky maine trails. Way better than my goldvalved 2007 250S. I have a great set of forks for about $140 including shims from Brewster to make the KLX axle work. The revalve was free as all I did was remove selected shims from the KX250 stack. The subtanks were a gift from another rider who rides twin chamber forks and no longer needs them.

I'm happy I was able to pull it off for so cheap, but I'm wondering if the stock basevalve couldn't benefit (a lot) from simply moving more oil. Last time I took a stock base valve apart, IIRC there are 4 square ports in the valve and only 3 same sized shims (more like a check valve).

Has anyone tried to simply open the 4 ports - or dare I say it - add 4 more to the compression valve? There is plenty of material in the valve to open the square holes to a round shape and plenty of room to tap 4 more holes between the existing ports.

If it would work, it would be a stupendously cheap, easy mod to pull off. All you have to do is turn the fork upside down and remove the basevalve. The mod would be as easy as enlarging the 4 existing ports and creating 4 more. If you wanted to get fancy you could alter the shimstack to an actual working stack rather than a checlkplate.

I'm probably gonna trade my KLX away in a swap for a 2007 KTM 300 XC-W. The guy who will be taking my KLX is shorter and I think the KLX will be too tall, especially with the KX forks on the front. I may want to go back to the stock forks (already nabbed a set of Kouba links to lower the rear by an inch or so) in order to maintain stock geometry.

I'm thinking of playing with the stock basevalves to see if the stock forks could be useable. But, before I do that - wanted to see if someones already tried it. Might save me the trouble of ruining a couple KLX basevalves.

 

dj, the stock basevalves won't approach the quality or quantity of flow of the Goldvalve design probably no matter what you do to them. If you didn't like the compression aspects of your Goldvalved OEM fork, why didn't you tweak the shim stack per the Race Tech instructions? They provided quite a few variable shim stacks in the damping characteristics going both directions from the "recommended" settings based on the info you provided. I can't say absolutely that the OEM compression piston can't be improved upon by opening it up in some way, but without a fork/suspension dyno, you're really probing around in the dark fairly blindly. The Gold Valve piston is a way superior design to probably anything you can do to the OEM piston.

The real benefit from many of the KX or other MX forks is the addition of an externally adjustable rebound circuit and often noticeably bigger stanchions. With all the listed available options in the Race Tech info and even the extra shims provided in the Gold Valve kit for the OEM fork, one should be able to get pretty much what they want for that fork. Still, there's nothing wrong with trying to dink with the stock piston if you're curious.

 

I did play around with the goldvalves on the 250S and was fairly well pleased. I was not able to get the same level of plush that I had on my KTM 43mm boingers. On the 300R I decided to go a different direction and found a better solution than the goldvalves - the KX forks are tremendous when revalved and the subtanks add a level of plush I've not experienced before. In fact, I'll say this - I'll never run another set of open chamber forks without subtanks.

The purpose of this exercise is to see if there might be an alternative for the vast number of KLX riders who cant afford either the goldvalves or the KX forks but would be willing to put in the time to alter what they have on the bike with a simple drill bit.

My gut instinct is that it would end up being somewhere between stock (couldn't be any worse after all) and goldvalves. And for the sum of exactly $0 invested, may just be another option. OTOH, it may be a deathtrap as well.

Obviously, there is only 1 way to find out, and that's to do it and see. I was just asking in case somebody's already given it a shot and thus can offer a great reason for me to NOT try it. I've actually got a set of old 300R forks leftover from a forkswap years ago. One of them was dented, bent and otherwise corrupted so I never bothered to sell them. The basevalves would make an excellent testbed for such a hairbrained scheme.

 

I'm listening with my full open ears

Now that I have a few years experience with my KLX, I have no problem believing a plusher suspension would be beneficial. As I understand it, a good piston/valve setup enables firm handling while absorbing better the mid and large hits.

However getting more plush while improving on bottoming resistance is beyond me. They appear exactly the opposite. I may miss something here.

But so be it, I don't want to spend for aftermarket valving as I consider my KLX is already old. If something can be done to the stock setup, I'm highly interested.

 

While it sounds counterintuitive to be able to achieve plushness with really controlled bottomout, it's very possible. The compression piston design coupled with a shim stack that allows a smooth, controlled transition through the shock or fork stroke can yield an almost perfect balance of suspension control. Then consider that open bath forks also have the ability to use oil level to smooth bottomout, and you can have a really well balanced suspension from a plush start to a smooth bottomout. Of course there is always a small amount of compromise in most cases, but you can get a suspension to work pretty darned well overall.

The real major pain with the OEM KLX fork is the compression spiking caused by a somewhat restrictive compression piston. It just doesn't flow enough oil for even a good shim stack setup to do its job. I'm not a fluid flow dynamics engineer by any stretch of the imagination, but I do know there's a specific reason for the way the holes and flow passages are designed in those quality aftermarket piston valves like Race Tech, Moto Pro, etc. I get the impression that it's not just having plenty of holes for more flow. It's how the oil is directed though the valve that has a noticeable improvement in damping. The fancy, schmancy curves and angles in those aftermarket valves are probably there for a very specific reason.

 

For the shorter rider:
Is there enough distance between the tire and front fender to raise the KX forks in the triples? A set of handlebar risers could be installed between the upper triple and the handlebar mounts so that the forks could be raised further than stock.

Ride on
Brewster

 

Brewster - IIRC, the KX250 forks are at the top of their travel within the constraints of the top clamp. That is, if I move them any higher I think I'm off the part of the outer tube which has been machined to fit the clamp. I'll check tomorrow.

TNC - you're probably right on the geometry of the aftermarket ports. However, the backwoods tinkerer(?) in me makes it impossible for me to NOT give it a try since those extra basevalves are sitting there anyway. In fact, they're sitting there hurling insults at me as we speak cause it's not done and tested already....