BB86 advice

bsharp77
bsharp77 Posts: 533
edited March 2015 in Workshop
Morning guys,

Ive picked up one of the BMC frames (GF01) and just realised its a BB86 bottom bracket.

I already have an SL-K BB30 Crankset that I was hoping to use with it.
Is there any convertor that will do this or is it totally incompatible?

Ive had a google, but its just made me even more confused!! :o

Comments

  • rafletcher
    rafletcher Posts: 1,235
    Don't think so. BB86 (width of BB shell 86mm'ish) has a bearing outside diameter of around 40mm, and the BB30 crank (30mm diameter axle) needs a bearing with a 30mm bore. (40-30)/2 = 5mm and that's not enough to get two bearing races and bearings in (well actually you probably could make a needle roller bearing to fit, but I don't think anyone does). So you need a crankset with a 24mm axle - I managed to get such a Rotor 3D+ crankset a couple of years ago.
  • bsharp77
    bsharp77 Posts: 533
    Ah thanks raflecther - that was my sinking feeling!!

    Its all as clear as muck - i want to pick up something nice (but not too dear!), I've SRAM Red components for the bike, so can I use a red crankset with GXP fitting?
    Shimano cranks look like they will fit, but I don't fancy a shimano crank with the rest sram red (such a tart!).

    The SL-K was perfect - even red and black to match the frame, but will have to go to the classifieds if it won't fit
  • brettjmcc
    brettjmcc Posts: 1,361
    speak to Velotech. You may be able to get the Rotor 4130 BB to work. http://www.velotechservices.co.uk/shop/ ... 7410001938

    I have the same frame as you that I am building up and have a Rotor Power with the UBB30 axle. I will be using that BB
    BMC GF01
    Quintana Roo Cd01
    Project High End Hack
    Cannondale Synapse SL (gone)
    I like Carbon
  • rafletcher
    rafletcher Posts: 1,235
    Ah yes, I HAD seen that before, so apologies, my initial post is incorrect! Live and learn.
  • bsharp77
    bsharp77 Posts: 533
    A massive thanks to Brett for pointing me in the right direction!

    Jon at Velotech came back to me straight away with the required convertor - I've now placed the order for delivery early next week - couldn't have been more straightforward.
    Looks like ill get to use my SL-K after all!

    Thanks for all the help, as always the BR forums come up trumps.
  • Monty Dog
    Monty Dog Posts: 20,614
    BB30 crank is designed to fit a 68mm wide shell, BB86 is 86.5mm wide - that's some interference fit! Surprised Velotech didn't pick this up.
    Make mine an Italian, with Campagnolo on the side..
  • robbo2011
    robbo2011 Posts: 1,017
    You can use the sram red crank with bb86. This is what i am using with my bmc slr01.
  • ror3h
    ror3h Posts: 68
    As someone else said, BB30 cranks will not fit in a BB86 frame. The spindle is simply not long enough.
    However, a GXP crank would fit, as would a BB386 I believe, and of course Hollowtech II.

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