Originally Posted by
subgrade
On a related topic - what adverse effect comes from a worn tension pulley? Obviously, a worn guide pulley does negatively affect shifting precision and speed. But I suspect that with the tension pulley, given it spins freely and there is no play in the bearing, there shouldn't be much difference up until it is worn near round.
Am I wrong in thinking this?
With the plastic jockey wheels, the hole in the middle wears, and the jockey wheel can wobble. The chain can then rub on the side of the derailleur. Obviously, then it's time to do something about it.