Originally Posted by
crank_addict
I concur with steelbikeguy above. Likely most are 2° taper but its the taper length that gets to be trouble.
This is different than overall or between bearings.
Mix and match is a crapshoot to get the chainline, avoiding the arm base casting too close and bb interference. Then just as one successfully has the non-drive perfectly seated, the other may not because the drive side taper might be longer!
For the bb spindle fastening bolt type, there are some hacks to make it work but most here would cry foul and club me. So never mind.... 💨
One reason that I went with the Specialized BB was that I had a couple different axles on hand... gave me a decent chance of finding one that would work!
I also had a handful of Shimano cartridge BB's in the parts box too, which presumably would offer more options.
Having said that.. I was lucky that it worked out. Those bolts in the 50.4mm BCD get quite close to the BB shell! The arms did end up at least a mm or two further up the axle than they started. They do seem to have arrived at their final position, though.
I had a somewhat similar experience when mounting the standard Campy Record crankset on a new Phil titanium BB (on my Raleigh Team bike). They must not have been a perfect fit, despite Phil's assurances that it would be good. After a week or two of riding, the cranks got distinctly loose and required a bit of bolt tightening. Now I'm concerned that if I put the crank arms back onto a standard Campy axle, there will be a substandard fit. This is the sort of thing that makes me a little queasy about buying a used TA (or other) crankset.
Steve in Peoria