TimW

I just finished restoring a 70’s vintage bicycle. While testing and adjusting the campy nuovo record rear derailleur I noticed that in the small to small gear combination the chain tends to ride-up on the lower jockey wheel against the inside of the cage and occasionally it catches in there. I’m not planning to use this gear combination but I’m sure that I will inadvertently shift into it so I think I need to fix this. I’m running 39-52 in front and 14-26 in back, the chainline is pretty much right-on, the dropouts are square with the bottom bracket with the wheel centered, and the chain length looks right (I used Sheldon Brown’s instructions and there’s no slack in small to small and I can shift into large to large). The derailleur does have some play that puts it a little out of square opposite to the chain angle in small to small but it doesn’t seem excessive. I’m not sure what to do here. Any ideas?

Thanks, Tim

JohnDThompson 

Did you check the derailleur tab alignment?

bikeman715

the dérailleur's pulleys may be warn and need replacing.check the teeth on them.

TimW

Thanks for responding. This derailleur doesn't have a tab adjustment so I can't do anything there but the jokey wheels may be worn so that is something I can try. Also, thinking about it, more tension on the chain does seem to help so I'll try backing out the dropout adjustment screws.

Thanks again,

Tim