M950 XTR bottom bracket issue

[fattiman]

Did you remove the self extracting bolt covers when installing them back on?

Can’t remember tbh. Is there a special process for refitting them?

 

[d8mok]

Can’t remember tbh. Is there a special process for refitting them?

Yes otherwise the splines don’t locate properly and it damages the crank splines

 

[d8mok]

I have seen some xtr cranks with marks on the cranks which could only have been caused by the arm binding on the inside of the BB. Not sure how this happens as the arms should not be able to do this unless there's something wrong with the splines and they've allowed the arm to be over-tightened I'm guessing.

That happens when people use spacers when they don’t need them. Thus making the BB wider and the axle narrower.

 

[ishaw]

The correct process is to remove the self extracting covers, freeing the captive bolts. With the bolts removed you can see the splines and align correctly before refitting the bolts, tighten them up, then finally screw the self extractor covers back on.

 

[ishaw]

If the spacers are out back on incorrectly, you can end up with the BB cup too far outboard which will then bind against the arm.

Are you able to post a pic or visually confirm the way the spacers are set up and if the arm is literally tightening up against the BB cup?