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How do I find out the crank bolt size I need?

rflookrflook Posts: 72
edited October 2014 in Workshop
Hi,

Am trying to fix up my old (ish) Hardrock Pro and need some new crank bolts. The only problem is I cannot for the life of me find out which bolt I need (M12/14/15). The BB is a Shimano BB-ES25 and the crankset is a Shimano FC-M430C-8. Both of these are Octalink splines.

Can anyone point me in the right direction of the size I need.

Many thanks in advance

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    Measure the old bolt?

    Measure the hole. Will be a tad smaller than you need.

    Go to a bolt shop and pick up some bolts and see if they are the right size. Order that size. Be careful the bolts you pick might not have the right thread pitch so don't force them.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • dj58dj58 Posts: 2,074
    I don't know whether this is the one, try contacting SJS Cycles they may be able to help you.
    http://www.sjscycles.co.uk/shimano-fixi ... -prod8393/
  • rflookrflook Posts: 72
    nicklouse wrote:
    Measure the old bolt?

    That'd be a great idea, but the olds bolts are nowhere to be found :-(
    nicklouse wrote:
    Measure the hole. Will be a tad smaller than you need.

    Looks like it is 15mm so guessing I need M15 then?
    nicklouse wrote:
    Go to a bolt shop and pick up some bolts and see if they are the right size. Order that size. Be careful the bolts you pick might not have the right thread pitch so don't force them.

    How do I know what the right thread pitch is?
  • keezxkeezx Posts: 1,311
    You won't find these bolts in a hardwarestore.
    Buy standard crankbolts for Octalink axles and its good.
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