Is my rear derailleur set up wrong?

Phil_D Posts: 467
edited July 2011 in Workshop
I have been looking at my rear derailleur (Shimano Tiagra) and think that the top pulley is too close to the chain in pretty much every gear. On the big rings at the back it is almost touching and as a consequence makes a lot of noise when the chain runs through it.

I can't for the life of me work out how to move it away. I have tried adjusting the B screw but this is as far out as it will go (screwing it the other way moves the pulley even closer).

Is is something to do with the length of the chain?


  • explosifpete
    explosifpete Posts: 1,327
    The chain may be to long, to check first put it in the small ring on the front and smallest cog on the rear. does the chain look lose? is the derailer under any tension?
    Then put it in the large ring on the front and biggest cog on the back, can you pinch the a couple chain links together ? If so shorten it
  • Phil_D
    Phil_D Posts: 467
    I don't think that is the problem, having checked it. On small small, it is all quite loose, but there is a little bit of room for the rear derraileur to be even looser. In big big, i do not think I could even remove 1 chain link so it must be tight enough.