I just bought a replacement for an existing 113mm UN-72 which was starting to feel pretty rough. The spindles are the same length, the cups appear identical, they both say UN-72 on the body of the BB, but the new BB has the spindle about 3mm further to the left than the old one. That is, there is 3mm more of the spindle protruding from the left hand side and 3mm less from the RHS.
It's not a matter of the old spindle having somehow moved sideways over time, as I haven't moved the derailleur adjustment stops since I initially installed the BB. Have Shimano changed the alignment of these over time? The old BB is about four-five years old.
I just bought a replacement for an existing 113mm UN-72 which was starting to feel pretty rough. The spindles are the same length, the cups appear identical, they both say UN-72 on the body of the BB, but the new BB has the spindle about 3mm further to the left than the old one. That is, there is 3mm more of the spindle protruding from the left hand side and 3mm less from the RHS.
Is the new one a 73mm shell? They are usually stamped 68 or 73 in tiny print on the lip of the right side cup.
I just bought a replacement for an existing 113mm UN-72 which was starting to feel pretty rough. The spindles are the same length, the cups appear identical, they both say UN-72 on the body of the BB, but the new BB has the spindle about 3mm further to the left than the old one. That is, there is 3mm more of the spindle protruding from the left hand side and 3mm less from the RHS.
Is the new one a 73mm shell? They are usually stamped 68 or 73 in tiny print on the lip of the right side cup.
Hmmmm... now that you mention this, his problem sounds like what I found a couple of weeks ago. I put in a UN-72 and the cranks were shifted to the left. Turns out the *new* bottom bracket was the 68mm width and the old bottom bracket was 73mm width.
Measure the width of the bottom bracket itself. Then look on the right hand cup of the new bottom bracket.
