Sheared rear rotor bolts

LAUNCH69
LAUNCH69 Posts: 119
edited April 2011 in MTB workshop & tech
Today whilst riding at Kelder, I noticed that I had no rear brake.
On closer inspection it turned out that the rear rotor bolts had sheared out of the holes damaging 3 and ripping one in half(the holes that is - no sign of the bolts).
Does anyone know what could of caused this, as I will need a new wheel and would like to avoid this in the future . . Especially as the downhill parts were a little scary with only the front to use after!
Cheers,
Si
Specialized Rockhopper

Bike is still better than the rider . . .

Comments

  • cooldad
    cooldad Posts: 32,599
    Either way overtightened or too loose.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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  • nicklouse
    nicklouse Posts: 50,673
    poor maintenance habits.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Northwind
    Northwind Posts: 14,675
    Things don't shear out of holes, they shear or they fall out. If there's a stub of the bolt in the wheel still then that's sheared but it sounds like yours have just come loose.
    Uncompromising extremist
  • Anonymous
    Anonymous Posts: 79,665
    As an aside, learn to love the front brake, it's the only one that will slow you down in virtually every situation.
  • cooldad
    cooldad Posts: 32,599
    Northwind wrote:
    Things don't shear out of holes, they shear or they fall out. If there's a stub of the bolt in the wheel still then that's sheared but it sounds like yours have just come loose.

    I think that a steel bolt in an alloy hole would quite easily rip the threads out if it was loose and had the leverage of the disc behind it. Or even more easily if overtightened enough to strip the threads.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • Northwind
    Northwind Posts: 14,675
    cooldad wrote:
    I think that a steel bolt in an alloy hole would quite easily rip the threads out if it was loose and had the leverage of the disc behind it. Or even more easily if overtightened enough to strip the threads.

    Absolutely. Or could have fouled the frame after it loosened, that'd put even more force on. But either way it came loose first.
    Uncompromising extremist

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