BB Spindle size compatible with HT2

Wheelspinner
Wheelspinner Posts: 6,608
edited December 2014 in Workshop
Background: I picked up a set of FRM cranks a while ago, still in a box, came with a BB92 press-fit BB setup. I'd rather use them now on a standard BSA shell, so need a new BB. Ordering one from FRM is silly money, so am looking for alternatives. The spindle diameter is listed as 25mm, *not* the Shimano standard 24, but the bearing size specified on their website is identical to that listed for Shimano at 37 *25 *7mm.

What am I missing? Why are Shimano bearings 1mm bigger than the axle diameter?? Is there a shim/sleeve or something I can remove and just use a standard Shimano HT2 BB for these cranks?

TIA...
Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS

Comments

  • nicklouse
    nicklouse Posts: 50,675
    The shimano use a plastic sleeve in the bearing to reduce the diameter to 24mm.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thanks Nick, presumably I can just lose the sleeve if needed and substitute with plenty of grease... excellent.
    Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS
  • nicklouse
    nicklouse Posts: 50,675
    Grease not needed as nothing moves. Just some anti seize to help stop axel bonding to beating race.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown