Can't shift, won't shift

revvers Posts: 81
edited March 2010 in Workshop
Hello. I have swapped my standard chainset for a Stronglight compact. I cannot now get the chain to go onto the biggest ring. I had removed my F.D as I'd had my frame re-sprayed, so have started from scratch. Rear shifting all ok. I have read stuff and watched a couple of you tube videos, but they only seem to cater for adjustment when everything is shifting ok. My group set is Shimano


  • MrChuck
    MrChuck Posts: 1,663
    Could be that your new chainset requires a different width BB, but probably more likely that your front mech is maybe a bit too high?
  • revvers
    revvers Posts: 81
    I bought a new UN54 BB which was 107mm and I have tried to get the FD as low as possible. It all seems to move ok but will just not 'throw' the chain up!! AARGGHH!!
  • Monty Dog
    Monty Dog Posts: 20,614
    Firstly, check your chainline by measuring the distance from the centreline of the big chainring to the imaginary centreline of the seattube on your frame - it should be 46mm - if it's way beyond this, then you'll need to fit a shorter bottom bracket. It's unlikely to be too short because your chainring would hit the frame. If your chainline is OK, you may need to adjust the stop screws on your mech. If you follow the instructions on you can't go far wrong.
    Make mine an Italian, with Campagnolo on the side..
  • revvers
    revvers Posts: 81
    I've just checked and I think I've bought a 110mm BB and I should have got a 107mm :oops: