Originally Posted by
aotearoa706
The bike shop is correct.
The Campagnolo B.B. has an ISO taper and the Shimano one has a JIS taper. These have different taper angles.
Although they ‘appear’ to be interchangeable they really are not.
Apparently you did not read the whole thread. Here's a quick recap:
The Campagnolo crank has a Campagnolo taper.
The Shimano Dura-Ace spindle he has has a copy of the Campagnolo taper.
The reason they do not have ISO or JIS tapers is that
those standards did not exist when the parts were made.
The taper thing doesn't matter anyway because the problem is that his fixed cup was unscrewing because sometimes Italian thread cups do that unscrewing thing.
The bike shop is therefore wrong in more ways than one.
The End.