bottom bracket advice

cyclosteve
cyclosteve Posts: 150
edited October 2011 in Road buying advice
i need help. at moment i got ultegra 9 speed groupset double. the bottom bracket is 109x68 english thread i am told by lbs.i am looking at the new ultegra 6700 but the sites never mention the bottom bracket sizes they just say english thread does this mean that there is only two lengths tripple or double before i place a bid

steve

Comments

  • stokey1964
    stokey1964 Posts: 454
    the bottom brackets are the same if you are running double or triple

    A triple should come with spacers with the crank set


    apart from that they are identical


    Simon
  • Wirral_paul
    Wirral_paul Posts: 2,476
    Dont you need a 6500 bottom bracket if your chainset is 9 speed? 6700 is 10 speed i believe - and has a totally different bottom bracket.

    109.5mm appears teh correct size

    http://www.ribblecycles.co.uk/sp/road-track-bike/Splined-6500-Bottom-Bracket/SHIMBTBR650?utm_campaign=Googlebase&utm_medium=organic&utm_source=Googlebase
  • Wirral_paul
    Wirral_paul Posts: 2,476
    Are you just looking for a new bottom bracket or a crankset too?? Its not clear to me really
  • cyclosteve
    cyclosteve Posts: 150
    i am looking to replace complete groupset i asume the arm conected to the crank must be standard length and the bottom bkt part of frame must be standard width excuse my ignorance i just ride bikes not understand the workings
  • RedJohn
    RedJohn Posts: 272
    cyclosteve wrote:
    i am looking to replace complete groupset i asume the arm conected to the crank must be standard length and the bottom bkt part of frame must be standard width excuse my ignorance i just ride bikes not understand the workings

    If you're replacing the whole group, it's easy. You need BSA (British Standard Authority) BB cups or external BB. Everything else will fit into those. The new crankset will have is own spindle so no need to worry about length.
  • LongIslandTom
    LongIslandTom Posts: 51
    i need help. at moment i got ultegra 9 speed groupset double. the bottom bracket is 109x68 english thread i am told by lbs.i am looking at the new ultegra 6700 but the sites never mention the bottom bracket sizes they just say english thread does this mean that there is only two lengths tripple or double before i place a bid

    Your 9-speed Ultegra BB is 109x68, because it has a 109mm-long Octalink spindle, to which the crank arms are bolted on.

    The newer 6700 Ultegra is completely different ("hollowtech 2"). The bottom bracket does NOT have a spindle, unlike your old system. That is why it's just a 68mm-wide English-thread bottom bracket, with no spindle length. The spindle, right crank arm, and chainrings are now one single piece, which you insert through the external-bearing BB, then bolt the left crank arm on to fasten the whole system together.

    New Hollowtech-2 Ultegra cranks and BBs are not compatible with old Octalink (yours) Ultegra cranks and BBs.

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