One of my friends damaged a pulley on his rear derailer. He contacted two LBSs and both told him the whole derailer would need to be replaced.
I have removed these several times myself for cleaning. It is easy to do.
Is it really true that replacing these pulleys require the replacement of the whole derailer?
It looks like I found them here.
I am about 99.9% certain that he has a Shimano RD, I am not as certain of the model, I would guesss a 105. Would these work for him? Which one would he use? Yeah I know, count the teeth but what are the numbers in the description, how does that relate to the type of derailer he has.