Originally Posted by
T-Mar
There could be several issues at play. The levers, the old chain, cable issues or a bad cog. First thing I'd do is try it in different cogs. If it only happens in one then it's the cog itself. The switch back to the old wheel. if it disappears, it's the chain. It is probably too wide and the hard exertions cause just enough movement for it to catch on the next cog.
I agree on this and on one bike I bought from a CR member no less, the chain and freewheel were gone. New components did not fully fix it, so the balance of the problem was worn out jockey wheels.
I have out of this really unique chain whips made from Regina Record Oro chain though.
On my freewheels the one to watch wear wise is the 17 t 42 x 17 is such a nice happy gear to spin in.