davf1 said:
I didn't actually want to increase the Q-factor as such, but reduce the clearance at the bottom bracket, if that makes sense. Anyway I have ordered a set of the Miche Primato which I hope will give me enough for what I want. Guess I will have to stop pedalling like a duck lol.
If you
just want(ed) a shorter spindle, I am pretty sure that you can mount your crank onto a
102mm Campagnolo Record/Chorus BB ... the taper hasn't changed from way-back-when till now. You probably have one, so you could do a "quick" test fit ...
I'm not sure if those Campagnolo BBs have more (initial) resistance than you want -- you could "flush" the grease out & relube (tedious?), accordingly ... or, go to a bearing shop & hopeully get replacement (non-sealed) cartridges OR possibly some unsealed "caged" bearing cartridges with the right dimensions ... maybe, someone has ceramic bearings/cartridges that will fit.
The double-cartridges on the drive side were poorly spec'd, IMO ... it would have been better if the cartridges were the same size as on the non-drive side where the actual size of the ball bearings inside the cartridges would
not have been closer to
Red Ryder BB-size than to the size that is typically found in a BB ... consequently, you CAN crack those bearings under heavy load & you should probably anticipate replacing them.
If your frame has an Italian threaded shell, I think I would consider mounting the Campy 102mm BB in reversed position where the single cartridge is on the drive side and the two smaller ones are on the non-drive side ... OR, reverse it IF/(after) you need to replace the bearings due to an actual failure (sounds ominous, no doubt).
If the 102mm spindle
is what you want, you CAN probably get a cartridge bearing that will sleeve onto the drive side of the spindle whose outer diameter will nest in a NORMAL ("vintage") BB cup, so THAT inner diameter dimension of the cup can be the outer dimension of the bearing -- all of that may be more fiddling than you want to do. Anyway, in that vein, I've mounted Shimano BB cartridges into French BB cups & a set of old/proprietary Raliegh cups by using internal shims to "center" the cartridge.
I had not given a lot of thought to reversing the internals of an English threaded 102mm Campagnolo BB, but, it could probably be done without too much effort if you use OTHER cups & are willing to fiddle with it.
Of course, more importantly, I'm not sure if your crankarms will still clear your chainstays -- depending on your current BB spindle length, the arms will be 3-to-5mm closer to the stays -- I would think they would/should; but, you'll want to measure the existing gap to make sure you will have MORE THAN 1mm after mounting the cranks on a 102mm spindle.
Of course, THE SHORTER SPINDLE WILL AFFECT THE CHAINLINE, so you'll have to weigh the dis-/advantages & may not want to use it.
