azza_333

I have a relatively new bike, I have only put around 1500km on it so far, and it has a very irritating rattle (although can be quiet subtle at times), but here is the interesting thing the rattle doesn’t start until maybe 10-15min into a ride.

Any help anyone can provide would be greatly appreciated thanks. As it is driving me crazy.



What I know so far:

- Rattle only starts about 10-15min into a ride.

- It doesn’t matter if I am putting 50 or 500 watts through the cranks the noise is the same.

- If I turn the cranks by hand there is no rattle.

- The noise is the same in both big and small chain ring, and all sprockets on the cassette.

- The noise also exists when back pedalling, but its much more muted and shorter.

- It only rattles when pedalling (seems to be in rhythm with my cadence).

- It sounds like its coming from either the front crank area, or the rear cassette area.



What I have tried so far:

- Swapping pedals,

- Swapping rear wheel (but using the same cassette)

- Swapping Chans

- Checking the front and rear derailer indexing.

- Removing the cranks, cleaning/regreasing the threaded bottom bracket and cranks
- Tightening the chain ring bolts

Outrider1

Saddle or seatpost? I'm assuming it only happens with you on the bike.

azza_333

Nope when I ride out of the saddle as well.

Jockie

Loose valve nut?

m.c. 

This is what my mystery rattle was. I thought I had it narrowed down to a loose spoke on the front because it sort of had a ping sound. The presta valve nut was just loose enough to rattle against the rim.

superdex

This also happened to me. Telltale sign is it rattles (more) over bumps. And if you don't have valve nuts, put some on, the valve stem is rattling in the hole....

Also check loose spokes.