ChrisEyles
Guru
- Location
- Devon
My commuter recently developed a slight "clonking" noise when pedalling against resistance. As well as being kind of annoying, I don't want to ignore a warning sign and end up with an expensive trip to the LBS!
The noise occurs once per revolution of the pedals, when the left (non-driveside) crank is pointing more or less straight down. It doesn't occur when back pedalling, or pedalling gently - for example I can't replicate the noise lifting the back wheel off the floor and turning the cranks by hand. It only happens when some effort is being applied e.g. up hills or maintaining speed on the flat etc. The noise is slightly quieter if I get out the saddle on a climb, but still happens at the same crank position.
I had a look on Sheldon Brown's site, and it seems the most likely culprits are the BB or the pedals themselves. I've checked both of these, and they seem to be good and tight, with no play anywhere that I can detect. The BB is a cartridge type, so I guess I can't adjust this like I would do on an old style cup/cone setup. It has done around 4,000 miles without any attention - is it likely it simply needs replacing?
I also checked the chainrings, and they aren't coming into contact with the FD. No kickstand or anything for the cranks to catch on either.
Any suggestions gratefully received!
The noise occurs once per revolution of the pedals, when the left (non-driveside) crank is pointing more or less straight down. It doesn't occur when back pedalling, or pedalling gently - for example I can't replicate the noise lifting the back wheel off the floor and turning the cranks by hand. It only happens when some effort is being applied e.g. up hills or maintaining speed on the flat etc. The noise is slightly quieter if I get out the saddle on a climb, but still happens at the same crank position.
I had a look on Sheldon Brown's site, and it seems the most likely culprits are the BB or the pedals themselves. I've checked both of these, and they seem to be good and tight, with no play anywhere that I can detect. The BB is a cartridge type, so I guess I can't adjust this like I would do on an old style cup/cone setup. It has done around 4,000 miles without any attention - is it likely it simply needs replacing?
I also checked the chainrings, and they aren't coming into contact with the FD. No kickstand or anything for the cranks to catch on either.
Any suggestions gratefully received!