Fulcrum rear wheel making "tink tink think" sound

[jwrightdesign]

It sounds like a tink tink from the spokes, but I can't figure it out specifically. I'm positive it's the rear wheel making the noise. I run campy 11 on two bikes and the wheel makes the noise on both of them. It makes the noise only in the easiest 3-4 cogs under load, never while coasting. Going faster makes faster "tink" sounds, again only under load. I can't reproduce the noise on the work stand. It is not from the wheel spokes hitting anything on the bike, because it happens on two different bikes.

I have tried (and not fixed the problem):
1) Brand new cassette
2) Brand new chain
3) Taking the hub apart and regressing everything (note it was dirty and needed it anyway)
4) Lubed each nipple contact point

Im at a loss. Google search didn't help me figure this out. Any help or thoughts is greatly appreciated!!

[sungod]

have you checked the spoke tension?

[bm0p700f]

I could be spokes knocking against each when the wheel flexes. the thing is spokes wont loose tension over time. If one spoke looses tension the wheel will be out of true.

I take it the hub works perfectly as in there is no play anywhere. Difficult to know really with seeing it and even then it maybe hard to cure.

[DuncanS2]

Yep I'd be betting spoke crossings binding then shifting when the wheel is under load. At times it can drive me mad with my zipps on a slow climb; also noticable when first rolling out "cold" on a ride. Try running a drop of lube down each spoke so it infiltrates between the crosspoints; may or may not help.

[jwrightdesign]

To answer some questions:

1) Yes hub works perfectly, smoothly and is now super quiet, no play
2) Spinning the wheel on the bike on the work stand there's no wobble whatsoever, so it appears that it is true.
3) I've tried lubing all entry points for the spokes, and the crossings too. Didn't help, but what you're talking about with your zipps sounds very similar - very noticeable on a slow climb. Might be because there's not as much ambient noise as other times, but that's when I hear it most.
4) Spoke tension. I don't know how to check this.

Sounds like I need to take it in to the shop right?

[mr_tim]

Could be the valve in the wheel - you get the same tink sound with deeper rims & most people either tape out the outer circumstance of the valve to resolve or dress over the valve say with tape so it can't move around.

or

Could be the cassette if not a) torqued down enough, b) not clean between the interfaces where the upper 3 cog set meets the next group. Slight play or movement at that point will also create noise underload.

Also worth checking the various spacers & plates in the cassette, occasionally you will find a plate which is cracked and so the compression & tightness of the cassette is compromised at the break / crack on the spacer within the cassette stack.



Spoke tension - grab groups of spokes (say two at a time for radial lace). If one feels looser than the other, its indicative of one spoke being not tight enough.. just lightly grab so you test / feel for tension.. you should get the general impression of how tight the generally are and so which one might be loose if it is. Or you can use a tension meter.. but grabbing by hand is the low budget basic version.




If you are unlucky it could be bad rim and a pinned joint that is loose.. used to happen all the time on mavic rims years ago.

[nafaiutb]

I had a similar sound from a Campagnolo rear wheel once - turned out to be a broken pawl in the freewheel. Worth checking perhaps?