I recently did a fairly significant, much needed rebuild of my wife's IF Crown Jewel with Campy Chorus components -- new bottom bracket, new chainrings, new cassette, new chain, new Ergo shifters, cables, and cable housing.
My wife is elated with the improved performance of her bike, but there is one problem that remains - chain skip. It is a pre- and post-rebuild problem. The skipping occurs when the chain is on the small chainring and on the larger cassette sprockets (she has an 11-29 10 speed setup), and only when there is a lot of tension on the drivetrain, particularly when climbing. She thinks (but is not certain) that the chain both skips without changing gears and skips while dropping to a smaller sprocket.
I have ruled out the following - chain size, chain wear, cassette wear, chainring wear, (all these are new), and indexing adjustment. As well, there is no indication that the derailleur mount has been bent out of alignment.
When I reviewed the Campy RD adjustment instructions, they said that the B Tension setting should be at full stiff, and so I set it that way. While shifting the gears on the stand, everything appeared OK and I did not make any adjustment to that setting. However, when we rode yesterday (first time with new ergo shifters) with the B tention at full stiff, the chain skip was more pronounced and occurred on even the third and fourth largest sprockets.
I am thinking that this chain skip problem may be related to the B tension setting, and possibly a worn-out spring in the derailleur (I cannot detect any movement of the top pulley when I adjust the tension screw).
If it is not the B tension setting, is there anything inside the freehub (I'm not sure about that nomenclature) that could be worn out and causing this skip? There's probably 10k miles on this bike and I haven't taught myself to dig into the hubs yet, so that is all original equipment.
Sorry for the long post. Any thoughts, advice, ideas would be quite welcome. Thanks in advance.
p.s. One other idea - what are the symptoms of worn-out RD pulleys?