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Dropping chain

phil485phil485 Posts: 338
Hi all,

Ive just put a Cervelo P3 together with Ultegra di2 and I'm really struggling with the chain dropping. The front mech seems to be adjusted ok but has anyone got any clues what might be causing it.

on the workbench everything shifts ok and under low power its the same. with a bit of load however as I shift from small ring to big , it starts to shift ok, seems to miss at tje front of the big chainring and then falls off to the inside and traps against the frame.

Ive not had issues setting a front mech up before. The inly thing of note is I am using the TA chainrings from wiggle on a quarq crank.

Any ideas??

Posts

  • slowmartslowmart Posts: 4,087
    Have you set the limit screws correctly?
    “Give a man a fish and feed him for a day. Teach a man to fish and feed him for a lifetime. Teach a man to cycle and he will realize fishing is stupid and boring”

    Desmond Tutu
  • david37david37 Posts: 1,313
    Often a sign of worn teeth on the chain ring, though from your description they sound like they may be new. Have you gotthe right ones? And is the chain new?

    Assuming youve st the derailleur limit screws correctly and the mech is parallel with the chainrings plus not too high.
  • phil485phil485 Posts: 338
    Thats whats annoying. New chain, new rings, limit screws set right and parallel. It may have been a bit high corrected now, need to give it a ride.
  • david37david37 Posts: 1,313
    phil485 said:

    Thats whats annoying. New chain, new rings, limit screws set right and parallel. It may have been a bit high corrected now, need to give it a ride.

    See how it goes now its at the right height. :)

  • Also... have you set the FD's support bolt?

    This secures the FD against the frame/mount and should the set up as well as the limit screws :)
  • Is there a maximum chainring teeth difference between small/big on chainset/front mech and if so have you exceeded it as assume this is a TT rig?
  • phil485phil485 Posts: 338
    edited 2 March
    I tinkered a bit more and last few rides seem to be a bit better. I am very aware and take it easy on the change and I've not dropped since. Problem now is the quarq appears to be broken with no way to fix :(
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