hollowtech 2 bottom bracket knocking

bobs bikes
bobs bikes Posts: 589
edited May 2011 in MTB workshop & tech
dunno whats up with this one.
i have a new hollowtech 2 bottom bracket and crank set.
everything is tight and secure, no play in any direction and smooth as it can be..... but....
it has a clunking noise like its a shot bearing or something, but all seems fine. its wierd.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    who fitted it?

    what size BB?

    how many spacers etc...
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • bobs bikes
    bobs bikes Posts: 589
    hi nick.
    i fitted it... and refitted it again and again.
    its a BB-51b unit fitted to a gt idrive 5. one spacer on the left, none on the right.
    i have tried it with all spacer combos but its still the same.
    it sounds like a ball is missing in the bearing. kinda sounds like windy millers sails going round.

    as i said, there is no lateral movement and all runs smooth, but its just this annoying clunk.
  • Matt 24k
    Matt 24k Posts: 186
    What year GT iDrive 5? Does it have the thin steel flex bone or the thick aluminium dog bone? If it has the flex bone it is really important to disconnect it before repairing the BB. It is not impossible to snap the flex bone whilst working on the BB holder if you don't undo it first. Then it is essential to torque all the iDrive parts to the correct values.
    I'm not saying this is the problem but I have learnt from experience and a few broken flex bones.
  • 5xcr
    5xcr Posts: 195
    hi, sorry this replys so late , and i assume you have solved the problem but just in case you haven`t , you say you`ve tried every spacer combination, but on my i-drive fitted with hollowtech 11 bb they is one spacer fitted on the right side(driveside) only. this ensures correct chainline and as i have found if not fitted correctly makes a horrible clunky noise.

    5xcr :oops:
    12hr days 5 days a week riding to work and back and still the energy to ride 2 other days

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