Spec Tarmac Pro SL3 BB question

Hurricane151
Hurricane151 Posts: 632
edited November 2011 in Road buying advice
Hi looking for some advice.

I have the opportunity to get a SL3 Tarmac Pro frame but I am a little confused about the BB. The spec says it is an OS Integrated BB. What does this mean? Is it a BB30? will it take a standrad GXP (looking to run Sram)?

Any advice would be greatfully accepted
TWITTER
Specialized Tarmac (Commuter)
Specialized Tarmac SL3 (Sunday Best)

Comments

  • LongIslandTom
    LongIslandTom Posts: 51
    Info on Specialized OSBB for their road bike frames here: http://service.specialized.com/collater ... racket.pdf

    There are two different "OSBB" types, as per that document.

    Older Specialized "OSBB" frames have BB30, which is 68mm-wide with 41mm inner diameter. The BB shell is aluminum. These require BB30 bottom brackets.

    Newer Specialized "OSBB" frames are PressFit 30, which is 61mm-wide with 46mm inner diameter. The BB shell is all carbon. These require PF30 bottom brackets.

    You need to find out which one your OSBB frame is, BB30 or PF30.

    Once the proper bottom brackets are installed, both BB30 and PF30 use the same BB30 cranksets. (The PF30 bottom bracket has external flanges that brings the total width of the assembly up to 68mm).

    If you want to use SRAM's GXP crankset with your "OSBB" frame, you need to buy the proper GXP-to-BB30 or GXP-to-PF30 adapter from Wheels Manufacturing to adapt the GXP crankset to a BB30 or PF30 bottom bracket.

    Hope this helps.

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