I have done my homework but can't find the answer in the campagnolo maze of components and compatibility. I want to switch to a 10sp campy compact crank and have identified 2 crank options while staying with the tapered BB. The Centaur CT with Ulta-Drive and the Veloce compact with EXA-Drive. My question is I thought EXA-Drive was an 8-9 speed shifting system and not a 10 speed, at least concerning the design of the rear cogs as to the way they are lifted from one cog to the other with slightly different indentations. So why does a Veloce 10 speed crank say "10 speed EXA-Drive" if the narrower 10 speed chains do not have protruding rivet heads and will pose a problem for EXA Drive? With the narrower 10 speed chains came the invention of Ultra Drive and the slightly different indentations on the rear cogs to catch the chain's outer plate on the narrower chain and assist the chain up to the next cog as opposed to the EXA Drive which used a wider chain with the exposed rivet heads. Its seems to me at least EXA-Drive and 10 speed systems are not compatible, yet Campagnolo makes a Veloce EXA-Drive 10 speed crank.
Maybe it would be safer to go to the Centaur CT although I would like to know what's up with the Veloce as it seems a cheaper option with the stamped aluminum rings.


thanks

I know it's not the answers you asked, but why limit your choice of cranks based on the BB. BB's are cheap. Pick the crank you really want and get the appropriate BB.

good point. The crank I want is a compact so that is established and it would be going on one of my mid-late 90's steel frames. Not a campy guy but I think I have a choice of Veloce with the Power Torque System & MPS (power torque BB arrangement), the already mentioned Veloce crank with EXA drive (square tapered BB) and the Centaur CT with Ultra-Drive & EPS (also square tapered BB). There may be other 10 speed compact cranks available but they seem to have come hand in hand with the 11 speed stuff which I don't desire.
I guess I am looking for the easiest transition to a compact crank with a possibility of using some of the already installed components or stuff I have stored in boxes.
I would even love to put a compact on a vintage 90's 6-7 speed bike with down-tube shifting (friction or indexed), using a medium cage derailleur and try to make it work without Brifters and all the other components associated to make their particular indexing system function (ergo, mps, etc). I wonder if anyone has ever done it?

Last April, I put a 11 speed Shimano 105 5800 group on a '91 Schwinn Paramount frame. Went to STI's on the bars and putting cable guides on the bosses where the shifters on the down tube used to be. I really like the STI's and regret not going to them sooner.

Some models of Campy square taper BBs and cranks are not compatible. A crank meant for a longer BB axle will hit the frame if used with a shorter BB axle.

I’m not familiar with the Veloce EXA drive but I suspect it is completely unrelated to the 8 speed cassette system. Record and Chorus compact cranks were made in square taper for a year or two before they went to ultra torque. They use the same 102 mm spindle as the regular cranks.

For whatever it's worth, my 2006 Bianchi came with a 10-speed Veloce drivetrain and the big chainring is clearly labeled "10 Speed EXA Drive". The teeth on the cassette look like the Ultra Drive ones pictured on Branford Bike's web site, though. And the bike's original chain, a KMC DX10SC, doesn't have protruding rivets, which seems to make it more Ultra-ish than EXA-ish.

I'm confident either crankset would work for you, especially considering Campy front shifting is essentially friction (ratcheted) and not indexed.

I haven't done it yet, but it's on my to-do list. I've got a crankset with 50/36 rings to put on my old UO-8, but other projects (new house) have pushed out the timeframe. I don't see why it wouldn't work since large chanring jumps are nothing new. Touring guys have used friction shifting on "half-step plus granny" triple setups for decades, and the jump between the small and middle ring on some of those rigs has to be at least as large as the jump between rings on a compact double.

Thanks for all the great input. I am quite sure the Veloce 10 speed EXA-Drive compact I was considering would have worked for the use I had intended and would have worked fine with either a EXA-Drive or Ultra-Drive rear cassette with of course a 10 speed chain. Just as an aside, Campy milled the crank arms a tiny bit (instead of using a thinner big ring) to accommodate for the thinner chain.
I am still studying how to incorporate a compact crank into my fleet (bikes with 126mm and 130mm) rear triangles. I am getting older and a compact seems to make more sense as my perfect gear seems to be around 30 gear/ inches with all the hills around here. Am evaluating either to stay "retro" by using early stuff like Veloce or Centaur maybe even ultra-torque or just going with a 105 11 speed as I am more familiar with the Shimano stuff.


Thanks again for the input on the EXA-Drive question.