Fagro

I have an early 90's Specialized Future Shock on my Stumpy. I havent used it in a while ( 3-4 mos). Today I cleaned the bike to start riding it again. I got on it and compressed the shock and it stayed in the compressed position. Would the cold temps have anything to do with this or is it much worse?
Thanks

garage sale GT

Springs have a finite life. you may have broken your spring or something which it needs to push against. That's sure old for a suspension fork. The good part is, if I installed a Firm Ride Kit (new spring) into my Manitou Axel Comp, chances are you can put a spring in your fork. I would contact the company, though, and see if they felt the rest of the fork might be at the end of its fatigue life.

I don't know how your fork looks inside but I would suggest trying to pull it apart and seeing if you could hear the spring rattling inside due to no longer being long enough to remain seated.

Fagro

I was afraid you would say that. The not so funny thing is, yesterday I was at the LBS eyeing a new full suspension bike. Coincidence? I'll have to do some research to see if it is worth fixing.

garage sale GT

I don't think light magnesium or aluminum castings such as fork lowers are known for good fatigue properties.

griftereck

have you taken the wheel out of it and seen if the forks move ok. It could be that the forks are not parralel. So would stick.
Be carefull when fitting a wheel. especially if the fork drop outs have recesses in the inner part of the drop outs for the wheel locknuts.

Also since youve been looking at new bikes. Your old bike will feel jealous and be in the huff. Dont think theres anything you can do about it.

roccobike

I can't help with the fork, but if that's a vintage steel Stumpy, don't toss it if you can't repair the fork. That bike is worth trying to find a vintage fork that's still operating or a new, low cost replacement.

Svr

Have you tried adding air to it?

It wasn't until 1994 that the entry level Specialized forks (Rock Shox Quadra clones) started using elastomers, and there were no coil sprung versions.

Fagro

Well, I took it all apart this morning. It looks as though this shock doesn't have a spring at all. Its all oil/valveing. No way to add air pressure either. I pulled the legs out of the crown, removed the "top cap?". The oil was all foamy. I emptied it all out. When empty there was no return or rebound after compressing it. It just sat there. I replaced with new oil, Dexron ATF because I had it. Put it back together. Semmed to work ok but, maybee a little too viscous(bottomed out easily).
Took it apart again and replaced oil with a heavier weight oil. Its a little better now. We'll see how it goes.

Svr

Forks of that vintage used a sports ball needle to inflate them. Was there a black plastic top cap on top of each fork leg?

Fagro

That may be it. There is a tiny screw in the center of the "preload?" knob on top of each leg. When I took the screw out nothing came off. It may be the plug for the needle hole.

Svr

The preload knob is actually adjusting compression damping blow-off (Platform damping in modern terms). Anyway -- use the sports ball needle (with the tiny phillips head screw removed) to inflate each leg to 30 - 50 psi. To preserve the inflation seal, lube the needle with ATF, suspension oil, or grease.

Edit: It sounds like you've got the Specialized version of the Rock Shox Mag 20.