Hello all

As I wrote earlier, I had an accident here in Sudan in which the front fork snapped and was fixed with new inner pipes from some other Yamaha (don't know which one). After somewhat recovering (both me and the bike) I managed to ride here to Khartoum where I've been getting the bike into better shape.

However, I'm not completely happy with the front fork. If I hit a bump the fork makes a 'clang' sound when it rebounds. Could it be something to do with the rebound damping? These new inner pipes are adjusted with compressed air and I don't know **** about that system. I've tried with 1 bar and 1,5 bar pressure but that has no effect on the rebound. Don't know about the amount of oil in the fork yet (if there is any).

Does anyone have any clue about what air pressure/amount of oil to use with this type of fork? Any other ideas anyone?

I know I could just DHL myself new original parts but I'm not giving up on this fork yet.

Happy Christmas

Jami

Glad your back to repair! There are a few on here who put Hyperpro springs in the forks so will now the oil and info you need...Im sure they will be along very soon to answer your questions

__________________
Previous bikes:TS50 - RD125LC - XT250 - ZXR750L3 - BMW 650 Funduro - BMW 1100GS - XT660Z Tenere

Is there any oil in the forks?
When you did the air pressure, did you use a hand pump as they don't require much pressure?
Are the yokes adjusted correctly onto the headstock bearings?

If you are getting the clang on the extension of the fork then I would suggest that there might not be enough or any oil in there.
Failing that the bushes might be shot.
I wouldn't worry too much yet, unless it's the headstock bearings.

15psi (1 bar) is plenty and I'd start around 5psi.

Check the oil. Hard to say how much should be in there, but with the forks fully compressed I'd guess you need ~ 200mm head space. If you want to stiffen them slightly, try a spacer ~ 20mm on top of the spring.

All estimates based on previous experience. The rebound noise could just be the fork tube hitting a stop or the spring hitting the caps on the inside. Once again look at the oil and put thicker weight oil in, say 15wt rather than 5wt. If you have no special fork oil, just use engine oil or cooking oil until you can get the proper stuff. Anything is probably better than nothing!

Good luck..

hi it's hard to know what is going on with the forks are the 'new' units really compatable with the lower legs? as it stands do the forks work correctly on compression?

anyway the forks require 650ml each, the otherway to measure is remove spring, compress fully, the level is 145mm from the top of the tube [both from yam manual] 10w oil is recommended, personally i use atf or powersteering oil in all my forks. works for me

stoic

The fork seems to work fine on compression. As far as I know the bearings have remained untouched. I haven't checked the oil level yet. It's more than possible that there's no oil inside at all. So you're saying it's the oil that has the biggest effect on rebound? I'm gonna check that tomorrow, thanks!

Jami