Knocking sound on a carbon bike

airone
airone Posts: 20
edited February 2010 in Workshop
I have bought a Focus Cayo 2008 second hand, with very little mileage. It makes a worrying knocking sound in the BB area when I ride a bump too fast. I have asked a fellow team member about it but he had never encountered this issue before. Everything appears to be tightly in place (in particular the bottle cages), so I'm at a loss.
If someone experienced this before, I'd love to hear before I splash £60 on a mechanics for no reason.
It's a KNOCKING sound, not a CREAKING sound (which I understand is common on carbon frames).
Thanks and enjoy the ride!

Comments

  • Not Another Hill
    Not Another Hill Posts: 382
    It's not a cable is it? On my Cayo, the cable guides that 'plug' into the frame are loose and they rattle/knock when jarred. Other than that, I can only think it is a BB issue rather than a frame issue.
  • Monty Dog
    Monty Dog Posts: 20,614
    Knocking is quite common - a frame is composed of big hollow tubes that tend to amplify noises - it's probably indicative of something loose, particularly the bottom bracket and headset. Check the axial load on the BB bearings.
    Make mine an Italian, with Campagnolo on the side..
  • Garry H
    Garry H Posts: 6,639
    You haven't taken it out in the rain, have you?
  • rake
    rake Posts: 3,204
    it wont corrode :wink:
  • rockmount
    rockmount Posts: 761
    It'll be the tappets ..
    .. who said that, internet forum people ?

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