I'm with Greg on this one, seems your tap may have become dulled by cutting chromed threads in the past? Your tap isn't cutting it (pun intended).
David Snyder Auburn, CA usa
Greg Parker replied:
> Are you saying that a loose cup (no spindle or bearings are in place) is
> that tight? And that several brands of cups have the same issue?
> If so, maybe the BB taps that you used are old and worn, so somewhat
> undersized? Are the taps for sure both 36 x 24 tpi? Or is the left-side
> one 1.370 x 24 (BSC)?
>
>>
Michael Schmid asked:
> Fellow List members,
> I am building up a beautiful golden Vetta frame and tried to assemble
> the BB-Cups. For some unknown reason the left BB-Cup will not go in as
> appropriate. I have reamed the threads with the proper Campy die tool
> (several times)and tried various different 24x36 threaded cups, none but
> one older used Rino right cup will go in well. All others will get stuck
> after some turns to an extent that i even broke the pins on my
> BB-wrench. I am totally clueless here since I do not want to ruin the
> pinholes or the wrench using to much brute force. I have, over the
> years, mounted a lot of cups, but it was never as hard as this time. I
> even tried some grease or WD 40 as lubricant without success.
> I have to say that it is fully chromed frame and i faced similiar
> problems but not as stubborn as this one on other chrome frames. Does
> anybody her have further ideas or hints? I suppose those left BB cups
> with the pin holes are not designed to be mounted forceful. The right
> cup was hard o mount too, but since it has the flats it was easy to use
> some more force, again with the proper Campy tool designed for this.
> Should I try to mount a right cup with more force to "loosen" or "widen"
> the threads? I suppose there is no special tool with more than two pins
> for this task?