help, can i use a italian threaded bb?

Discussion in 'Singlespeed' started by barbonator, Dec 3, 2009.

  1. barbonator

    barbonator New Member

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    i have an old italian fixed gear conversion but
    i have cottered cranks and the cotter pins
    are getting worn out so i might buy new ones.

    But i'd rather just get a new bb and replace
    my cranks

    what sizes can i use
    should it be a italian threaded, with this size
    70width 36mm x 24 tpi
    like this on sheldon brown -Shimano BB-UN54 square tapered Italian

    anyone else do this?
    can i even fit a modern bb?

    thanks for your time
     
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  2. alfeng

    alfeng Well-Known Member

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    Yes -- you can/must use ANY contemporary Italian threaded BB (36x24) ...

    You just have to 'remember' that the FIXED CUP is also right hand threaded ...

    AND, choose a 'matching' crankset.

    N.B. Campagnolo & Shimano have slightly different square tapers. SOME cranks use symmetrical spindles, others don't. Also, for example, a 118mm spindle may be used on some double cranks while the same 118mm spindle might be used on some triples! So, while you may be lucky in randomly selecting a square taper BB & crankset, you can't be sure you'll get a combination which will work together optimally ...

    So, 102mm Campagnolo BBs can only be used with Campagnolo Record & Chorus cranks from the past 10 years or so ... there may be a Sugino crank that uses the 102mm BB ...

    Most-if-not-all Sugino cranks use the Campagnolo (ISO) taper.

    OTHER Campagnolo cranks use longer, asymmetrical spindles. These cranks can be mounted on asymmetrical SHIMANO BB spindles as long as you understand that the crank arms will be a few millimeters further outboard on each side ... at the moment, I have a CAMPAGNOLO MIRAGE crankset mounted on an asymmetric, 113mm Shimano spindle.

    A Shimano crank (or, equivalent) will bottom out on a Campagnolo taper. Most Shimano cranks use asymmetrical BB spindles.

    About the only BB type that is hard to find with Italian threading are the ISIS BBs, and you should consider that to be a-good-thing because the ISIS BBs are, IMO, the least desirable/reliable of all the BB types due to poor bearings.

    FWIW. I'm one of the few people, apparently, who like the Octalink BBs.
     
  3. barbonator

    barbonator New Member

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    thanks really helps

    well i bought cotter pins today and they seem to work fine
    but ifound out my chain ring is bent so i might get a
    new set in the near future

    ill be brining my bike to a shop to find the right sizes
     
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