My coil U-Turn Lyriks seem to have a bit of a knocking noise as they rebound to full extension. This is not noticable on the trail and does it when I manually compress the forks and then lift the front wheel to allow them to fully extend.
Any ideas as to what may be wrong, if anything?
I had a similar problem with mine. My fork would clunk slightly when rebounding from low amplitude, medium frequency bumps.
I had a good look when I stripped them down and it seems that the damping plunger (?) that connects the damping cartridge to the bottom of the fork leg was slightly bent. I ended up rotating the plunger about 90deg and reseating it. For some reason this has stopped the noise on my fork.
Of course, you might have a completely different problem (perhaps the top-out bumper?).
-j
Or failing that, anywhere to get them serviced. I usually go to TFT but was wondering if there is anywhere else worth going.
Try turning the u-turn one or two clicks. My old Revs used to clunk at 130mm but didnt make the noise when I wound them down a couple of notches.
Cheers Aphex, I'll give it a whirl. Might send em off for a service anyway, although I've just changed the seals and replaced the oil so shouldn't need much, depending on what is causing the knocking.
Goin to Whistler in July so want them sorted for that.
I had a similar noise from mine. I took them apart and the oil in the right hand damper was well past its best. Not just a lower leg oil change: i had to take apart the actual damper cartridge. Service manuals are on the web: but you'll need a pair of circlip pliers to get in there.
Try turning the u-turn one or two clicks. My old Revs used to clunk at 130mm but didnt make the noise when I wound them down a couple of notches.
I have adjusted the u-turn and it only makes the topping out noise when they are at full travel - any ideas?
Does the noise come from the coil side only? If so it's 1 of 2 things, either:-
A) The spring is dry in the stantion.
or
B) The spring is not straight in the stantion, this is the probable cause and is recitified as follows:-
1) Remove the u-turn adjuster (Be carefull of the small springs and ball bearings)
2) Turn bike upside down & remove wheel
3) Slacken bottom allen bolt and undo until last few threads, tap with rubber / pastic mallet (Not hammer)then remove when the bolt is loose.
4) Remove the whole spring assembly by unscrewing the u-turn adjuster base at the top of the fork.
You will see at the bottom of the spring a plastic part that is attached via a shaft to the lower allen bolt you tapped with a mallet earlier. The shaft of this sometimes does not sit straight due to wear & tear as it is the moving part of the u-turn system. When the spring decompressesit is not straight and knocks the side of the stantion tube. The white plastic bush in the bottom of the stantion is the guide to prevent this angluar issue, however when this wears out the noise begins & eventually stantion wear internally (thats why there is a clear plastic protector in the stantion).
The way I got around this was to put a small hard rubber washer cut at an angle between the white plastic guide and the uturn plastic part, this corrected the problem and my fork has been fine ever since. Alternatively you can try an source a new guide for the stantion bottom.
Hope this has been usefull.
KS
Thanks for the info Stoner, that is useful. I will have a look at them and see what's up.
This will help too: -
Page 25.
🙂
Cheers mate, that'll come in handy.