Hello folks - I've got a Campy NR Pista triple and spindle that isn't working out with thick cups (not supposed to, I know). And I have one thin walled Campy fixed cup. I've heard of this being done before - any chance of being problem free if I just swap out the thick fixed cup for the thin one? As it is, too much adjustable cup is protruding and the crank arm seizes against it when I try to install. Trying to avoid going Japanese with these cranks and sets of Campy thin walls don't seem easy or cheap to come by ...

I read somewhere that smaller bearings can be used with the thick cups, but I'd think that going to a smaller bearing would, aside from increasing the wear, misseat the bearings in the races ..

Pista triple?

Velo Classique in VA had some NOS thin cups when I was there last fall. Pricy, but not too common. The late 70's Campy Gran Sport BBs also used thin cups, which I believe were identical the ones used on Record pista and triple BBs. So keep an eye out on eBay for those.

Should have said Pista or Triple ...

I'll look into it - thanks for the reference.

I think you're going to be out of luck with mixing the cups. The Campy Nuovo or Record Triple ( Triple or Pista thin cups ), pre-CPSC, uses a specific 117 or 118mm spindle depending on English or Italian threading, and uses thin wall cups due to the wider space between bearing landings. There is also a later post CPSC triple spindle, marked differently, which is much wider at 123 or 124mm.

Which era or year Triple and spindle do you have, and which threading type do you have on what kind of frame? In some cases, a later SR spindle at 115mm can also work to give clearance and correct chainline depending on stay indent and crank taper condition.