Originally Posted by
Duke7777
I would think your GS double crank should work with any post-CPSC ("New Style") Road Double bb. The 115 spindle is post-CPSC Italian, although you don't say whether it is Gran Sport or Record (both for thin cups) or Nuovo Record (rifled cups). I'm guessing it's NR, as I think this spindle would fit a 68mm bottom bracket shell when used with Specialized cups (a bit thinner than the rifled NR cups). The fact that you have insufficient chainring-to-stay clearance when using an Italian post-CPSC spindle may indicate that the crank tapers are quite worn.
There's no Road Double bb spindle with a length of more than 115.5 mm. You would have to go to a triple spindle, which are getting a bit expensive and hard to find. A spacer behind the fixed cup would be the best solution if about 2 mm is sufficient, otherwise you start to run out of adjustable cup thread available for the lock ring. Going to a rifled Campy adjustable cup would give you another mm or so of thread compared to your Specialized cup.
In a pinch, I've used brass shim on the tapers to get another few mm of chainring clearance, and it actually works quite well if you're careful.
I have spare Campy double bb sets in most configurations (no triple spindles though - I need them all) and may have something that would work. I'm in Vancouver, so you're welcome to drop by.
Thank you for that detailed response. It is indeed quite possible that the tapers are worn.
I have not actually seen the spindle in question - relying on info from the mechanic who disassembled recently, whom I know well but who would not likely be able to tell me if GS, NR, etc.
I think my friend with the cranks/bike in question would be keen to replace with a complete Campy bb unit - and I think an arrangement with a standard double BB and spacer that gained 2mm clearance from the stay relative to current would do the trick.
I would be happy to drop by and see what you've got (and to talk the problem out with someone obviously much more well-versed than I in these things). Sending a PM now.