Cycling UK Forum

On pedalling a distinct clunk comes from the rear derailleur- presumably its not related to the freewheel as its constant -I've looked carefully at the chain but cant see any bent links etc - I've ridden with it for hours the noise gradually increasing but nothing breaking, any ideas,

Toby

Once per revolution of the wheel? chain? cassette?
Is it only under load ?

On load only only and regularly which suggests the chain,

toby

Bobs question is vital to diagnosis, read it again and try and answer it.

If you are only getting it once per passage of the chain - ie approx every 2 to 3 pedal revolutions, then it must be the chain itself. I'd check it very carefuly for damage, especially if it only happens under load. If the noise is from the back, it might be something on the chain catching the derailleur cage, but as the chain is not really under load at that point, it sounds more like damage, which would fit in with it getting worse.

Whilst all the links may be there, have you checked all the rollers? also check the chain for fatigue cracks in the side plates.

Malc

i'LL LOOK FOR CRACKS/roller damage, however I'm not sure if I'll spot any. It was not running true on the upper cog but is now and is still making the noise. The chain + cogs have both been thoroughly cleaned recently,

toby

iT WAS THE PEDAL,

Toby