New bottom bracket problem

erifles
erifles Posts: 5
in MTB workshop & tech
Hi,

I am replacing a Shimano BB ES51 (Octalink) with a new Shimano BB52 (Hollowtech).

The new cups bind after one turn at the most and won't screw on any further. I am not too bothered about damaging the cups as the BB is £15 but I don't want to force them and damage the frame.

The old BB screws in and out easily by hand. I assumed as they are standard English sizing they would be a straight swap. Has anyone had this problem before or any ideas how to get around it?

Thanks,

Ben

Comments

  • reaperactual
    reaperactual Posts: 1,185
    edited July 2020
    Have you cleaned and greased the threads?

    The non-drive side on the English standard is a right hand threading, tightening clockwise. The drive side uses a left hand thread, tightening counterclockwise.
  • erifles
    erifles Posts: 5
    Yes, I've cleaned the threads.

    The drive side tightens anti clockwise. The non drive tightens clockwise.
  • reaperactual
    reaperactual Posts: 1,185
    edited July 2020
    Double check for the correct orientation of the cups, shell threads and the cup threads for damage?


  • The Rookie
    The Rookie Posts: 27,812
    Like for like should be an easy swap as you summise, its hard to diagnose as you seem to have covered the common ones, the most common one is the wrong cup on the wrong side.
    A good blast with a light oil (WF40, GT85 etc) and screwing the OLD one in and out a few times can help clean any debris from the thread, finish by wiping with paper towel.

    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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