I'm ready to button my forks back up after a revalve and fork seal change.

RT recommends 4mm preload for my 2007 with GVs. When I measured the difference between the spring and space available for the spring I get about 25mm with the upper spring guide (round and fits between the spring and the cap) down to the lower spring support. So if I compress the spring into this position I'll have way over the recommended 4mm preload.

I notice that if I remove the upper spring guide and let the spring ride up into the cap that I'll end up with about 6mm preload which is a lot closer to the recommendation from RT.

I know I'm not going to shorten my expensive Moto-Pro fork springs

So, is there another answer to this dilemma - or is it really a non-issue on these forks?

 

Again, it's been awhile on mine, but if you do away with that upper steel spring guide/washer, it's going to ride against the aluminum cap. While that aluminum cap isn't made out of cream cheese, I'd be a little concerned about it as the spring does tend to squirm around a bit.

I used Race Tech KLX300 springs in mine, and RT gave a range of 5-20mm of preload. Not sure why MP would give such a singular number for preload. I think any quality spring gives an allowable range of preload tuning. I can't see how 2mm...if I'm reading you correctly here...will make much difference.

Also I notice that you mention RT's recommendation of 4mm of preload. My paperwork for my '06 fork...same as yours...recommends anything from 0-10mm of preload. Their fork spring kit, however, allows for anything from 5-20mm. Go figure. The point is, and from past fork spring experiences, that leaving that washer/guide in there probably won't even be noticeable...unless you're running some very heavy springs that might already be too harsh.

 

Thanks TNC. No, actually I'm running Moto-Pro .44 springs and if anything I think I may have gone with a .46 for my 200 (out of the shower) pounds. So, I think the add'l preload may work out in my favor a bit.

Thanks for putting it in perspective. My only other fork work was on WPs and the spring fit right up into the cap with nylon spacers to make the correct preload. Again, nylon protecting the aluminum cap.

 

Yeah, I'm almost your weight, and I'm running .44's. I have mine preloaded 19mm, and they're just about perfect.

 

Don't sweat the small stuff. A couple of millimeters out of the total fork travel won't be noticeable. The shim stacks will have a much greater affect on how the forks work.

Ride on
Brewster

 

Thanks Brewster. I didn"t know you were on this forum. You were a great help to those of us on the old Planetklx.com. In fact, one of the reasons I kept my stock forks rather than upgrading to KX forks on the 250S was that I was afraid I wouldn't be able to get your axle spacers again.

I took it out today in the pouring rain (3 days of 50 degree rains in a row. Global warming my azzz) and ran one of my standard rides. The forks are so much better that I could go as fast in the rain/mud on the GV revalved forks as I would have taken it in dry conditions with the stock forks. I even picked the ugliest line through most of it just for grins.

The compression spike is definitely gone. Much easier to blow deep into the stroke as it should be. I can see now that I would love to play with the rebound a bit (could use a bit of damping there as well) to get it perfect - but about 80 percent of it's bad habits are now gone. Much less tiring to ride, even in the poor conditions. Way better onroad as well. Our backroads here in Maine are so rough I really hated taking my Bandit 1250 out over the last week while I had the forks off the KLX. It was bone-jarring at times. It was even hard with the KLX and it's stock forks. No problem at all now. They soak up all that road junk with ease.

Unfortunately, it becomes pitifully obvious how iffy the shock is now. I seem to remember TNC saying that it's even easier to break into the shock yourself than the forks. Sounds like a good winter project.


In comparison with other good forks I've owned - I think my open chamber WP's (400 EXC)were slightly better but only after revalving. Even then - probably only due to the rebound adjustment. They are about the same to just slightly behind the 45mm Marzocchis on my TE610. I actually think the compression valving on the GVs is better than the Zokes, but once again, rebound damping was asjustable.

Anyone know how to play with the rebound on our stock forks? Now that would be a real gift.

 

On the rebound on the OEM fork, Rick at Cogent has or had a KLX250 that he opened up and installed a rebound adjuster through the top cap. I don't know if he will do that for the open market, but it's worth asking him. The only other way to tune the rebound is with oil viscosity, and that would screw up the damping package as delivered from RT. Now, you can find the oil viscosity that works well on rebound and then dial in the shim package on the compression circuit, but it might take awhile to hit the sweet spot...or maybe not. I would like my rebound to be a little faster, but it's not really a big issue for me. People are different.

Yeah, on revalving the rear shock, I really do think it's easier to work on than the fork. I'm serious. I think people are scared of the shock because of the nitrogen in the bladder. That's no big deal to get filled after the rebuild, and I don't use nitrogen anyway. I use air. But really, if you did the fork, you won't have a problem with the shock. And at your weight, you'll probably need the 6.0 spring like I did.