Originally Posted by
Grand Bois
Just not so. They're all made to take 11 1/4" bearings in and fit in the same size shell. The variance in thickness is on the face of the cup and would have no effect on the fit of a sleeve.
The guy who sold me the non-fitting sleeve was rather surprised - it fit a NR cup he had lying around, but not mine, as I showed him. Luckily he found another the right size (but only one), but I still need one for my city racer.