loose pedal thread in carbon si crank

pauli
pauli Posts: 59
edited July 2012 in Workshop
The insert into which the pedal screws into has come loose inside the crankarm on the drive side on the cannondale supersix si carbon crankset.
Any one have any ideas please. The bike has only covered around two thousand miles but is out of warranty.

Comments

  • keef66
    keef66 Posts: 13,123
    Warranty notwithstanding it sounds like the thing has failed. I'd still want it to go back to the manufacturer for a free of charge replacement
  • Yossie
    Yossie Posts: 2,600
    Yup - unless you can get a helicoil insert bonded in there, I think its jazzed.

    Back to 'Dale/the maker for a swap methinks.

    Sorry ……...
  • crankycrank
    crankycrank Posts: 1,830
    If a replacement from Cannondale doesn't come through, try one of the CF repair shops. They should be able to fix it but I have no idea of the cost.
  • keef66
    keef66 Posts: 13,123
    I know they are light and strong and lovely to behold, but this threaded insert malarkey always struck me as a potential weak spot with carbon cranks.

    I've now read 3 or 4 posts from people who've suffered the same thing; probably not a very high failure rate in the great scheme of things, but enough to make me stick with cheaper alloy stuff. That and my Yorkshire tendencies...
  • pauli
    pauli Posts: 59
    Thanks everyone, will try cannondale and see if they come up trumps. I'm a yorkshire man as well so probably go for alloy in future!
  • Barrydeek
    Barrydeek Posts: 12
    Hi Pauli ,
    I have just come by the exact same fault today , was just wondering if you had any joy from Cannondale or what did you do to fix it?
  • rpd_steve
    rpd_steve Posts: 361
    They can be fixed with either Time inserts or Keen inserts- helicoils/wire inserts will just distroy the carbon as they don't spread the load, but allow it to transfer to each thread, with the outer threads taking 80% of the load it soon leads to failure again. Solid inserts however spread the load through the entire arm.

    Expect to pay £30 or so for this to be done as the repair kits for time and keen inserts are several hundred quid and the inserts about £5 to £15 depending on size and material. (you can get mild, ss, ti ect)

    If you struggle then let me know by pm and I will sort a repair for beer tokens :-)

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