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BB30 Bottom Bracket

milanino-brancamilanino-branca Posts: 13
edited November 2013 in Workshop
Hi All
I have recently purchased a FSA Gossamer BB30 chain set which i would like to fit to a 68mm bottom bracket shell which has an english thread. Is it possible to use a press fit bottom bracket in a threaded bottom bracket shell or are the diameters of the shell totally different?
Many thanks

MB

Posts

  • Unfortunately that's not possible.
  • Thanks for your reply…..that was the conclusion I had come to myself but wanted it confirming.
    Cheers
  • Was looking for an adaptor myself last night (BB30 to Hollowtech 2) and stumbled upon this. On first glance it looks like it will do what you are needing, allow a BB30 crank to go into a BSA threaded frame.

    Might be worth checking with Sigma, but it certainly looks like this is now a possibility when before it was always the case this couldn't be done due to the differing sizes of the axles.

    Good luck!

    http://www.sigmasport.co.uk/item/Rotor/ ... QE?wmp=115
  • sungodsungod Posts: 13,722
    pretty sure the rotor cups won't work with a *standard* bb30 crankset...

    rotor's cranksets have a longer spindle than bb30 specification, on a real bb30 bb they use spacers to take up the slack, this long spindle allows them to work on a bsa frame using these cups

    but a pure bb30 crankset will not be wide enough
    my bike - faster than god's and twice as shiny
  • Monty DogMonty Dog Posts: 20,614
    Yup, the Rotor 30mm crank has a longer spindle to allow you to use them with a regular 68mm BB shell.
    The internal diameter of a 68mm shell is 42mm, a BB30 spindle is 30mm diameter which leaves 6mm either side for the bearings - by the time you add a couple of mm either side for the cups, you've got 2mm left for bearings (traditional loose-ball BBs use 1/4") which means they would probably last about a week...
    Make mine an Italian, with Campagnolo on the side..
  • Thanks Mitchgixer6 for the thread to Sigma……it may have worked but the spindle is not long enough in this case.
    Thanks all for your help
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