1989 KDX Front forks not rebounding? Need some help

[dirtbagrider]

So recently I replaced the seals on my 89' forks, I filled them with 10wt oil to the 140mm mark, reassembled them and when I was pushing down to make sure they would compress and rebound properly I found that they would not rebound at all but would have to be pulled back to get to the fully extended position. Has anyone had this problem before? Or have any pointers? Thanks!

[KDXGarage]

Wow. Perhaps incorrect reassembly?

[dirtbagrider]

I checked the front fork schematic and if I remember correctly I assembled it right.

[KDXGarage]

What happens when you pull up the forks?

[dirtbagrider]

So I looked at the forks again and they rebound alright when not clamped into the triple clamps, but when I clamp them in they don't rebound at all.

[KDXGarage]

torque wrench??

as in, any chance you are over tightening the clamps?

Clamps out of alignment??

[dirtbagrider]

I'm not sure what you mean exactly?

[dirtbagrider]

Ok how tight do they have to be? I'm not very mechanically inclined so any suggestions would be awesome

[KDXGarage]

Do you own a torque wrench?

[ohgood]

Ok how tight do they have to be? I'm not very mechanically inclined so any suggestions would be awesome

he's hinting that you're putting the fork tubes in a bind by over tightening the triple clamp bolts.

there is a spec for every bolt and nut that is used on the bike. check out the manual, and see what that is.

there will be a vast improvement in the longevity of your fasteners and threaded holes by observing those torques.

[dirtbagrider]

Yes I have a torque wrench. So I should find out the torque setting for each bolt and set the wrench to that torque? Thanks for all the help!

[Julien D]

Yes, that is correct.

[dirtbagrider]

Ok so the situation now is that when I push down on the forks from fully extended position they go in about 1 or 2 inches then they hit the point where they rebound. I think the 2" inches that the fork just slides in is because the inner fork tube isn't having any contact with the spring until it hits that 2" point. Is this ok? Or is there a simple remedy for this situation? Thanks for all the help by the way!!

[KDXGarage]

Have you read any on fork spring preload?

Are you certain the fork spring spacers are making contact inside the forks?

[dirtbagrider]

For the first 2" of press the spacer is not making contact

[KDXGarage]

SWEET. We're getting somewhere.

The spacers not only need to make contact, but need to compress the springs a little, as they set assembled. Race Tech recommends about 4 mm of preload (or compression).

In stock form, there are metal tubes inside the forks that provide the preload. You sound like you need to get some PVC pipe and make some new spacers that when assembled, will press the springs down 4 mm.

The length will be correct when you go to install the fork caps.... the fork caps will not screw down all the way without touching the spacer tops. They will touch the top of the spacers 4 mm before being fully threaded down. This will have the bottom of the fork caps touching the top of the spacers (and washer/s), which will then compress the fork springs 4 mm.

I hope that makes sense to you. It took me a while to figure out what it all meant when I got started working on suspension.

[dirtbagrider]

Ok awesome im getting some spacers right now and about it install them! Thank you for all the work! Thats awesome!

[KDXGarage]

You're welcome.

You can get some white PVC pipe and cut them to length. I think it is about 1.25" or so pipe. Try to have the ends sanded smooth, so no burrs chip off and float into the oil and compression adjuster assembly.

[dirtbagrider]

Ok so I finished the spacers reassembled the forks and put them on my bike took the bike for a quick spin in the rain and the forks work perfectly now! Thank you for all the help and suggestions!!

[KDXGarage]

BOOM!!

We got it done!

Good job.

I love this forum.