A Bicycle Jumping Chain Problem

Robyn has replaced his chain and cassette but has problems with the chain occasionally jumping on the cassette; this is always a tricky problem and could have a few different causes, as always we try our best to help out

Question: I have recently put on a new 9speed 12-23t cassette and Wipperman chain on Campag Neutron wheels. My chain seems to occasionally ‘jump’ as though it has a stiff link, however it is not consistent, i.e. some rides it will jump up to 10 times and other rides it will jump only 2-3 times. Do you have any suggestions as to how to fix this, or any possible causes? Thanks for your time. Robyn.

Robyn,

This problem usually happens because people replace the chain and not the cassette or the other way round, in your case you have replaced both and are getting the jumping problem. My first thought was maybe you have a ten-speed chain and this with your 9-speed cassette would cause problems.

The other reason I thought maybe that the chain ring teeth are worn or damaged, check that the rings are not bent by spinning the chain set while looking down on it and using the front derailleur as a guide you can tell if the rings are bent. To check if the teeth are worn, the gap should be round and not hooked, if they are hooked get new chain rings.

Also check the rear derailleur gear, the jockey wheels could be loose or worn, check all the bolts, if they are all OK then take your bike to your local shop and get them to check the alignment of the frame and the rear derailleur hanger and the derailleur its self as it may have been damaged at sometime, which would affect the running of the chain on the cassette.

I hope this all helps you solve your problem and you can get out on your bike without that jumping!