Swapping Cranks and BB?
 

I have an older (1981) Davidson custom frame with a Cinelli BB shell that has an old Zeus crank. I also have a newish (2005) Chorus crank and BB that was mounted in a Kuota carbon frame that I crashed. When I replaced the crashed frame I had them install an FSA compact crank in it, so the Chorus crank is now a spare. I'd like to put the new crank in the old frame. The old crank is pitted but still seems to function just fine, but I like the 53/39 over the 52/42. When did they switch to 53/39 as a standard anyway?

Is this an easy enough thing to do? Will I have thread problems? I don't know what the threads on either frame are, but I'm assuming Italian. Will I need special tools (probably)? Is installing a crank an easy job? Do they use the same spindle and could I just swap the crank and not the BB? And from an aesthetic standpoint, should I do this?

Your Davidson has an English BB. (I used to work for him. All English.) Cinelli made BB shells available in all popular threadings. I can't speak for the Kuota.

You will need a 16mm(probably, could be 15mm) thin-wall socket, a crank puller, a hook spanner, a pin tool, and a 36mm wrench to remove the stuff from the Davidson. 2005 Chorus is a bit modern for me, but I think you'll need a Campy cartridge BB tool and whatever wrench fits the crankarm fixing bolts. I can guarantee that the Zeus spindle is too long for the 2005 Chorus crankarms.

The 39t inner rings became popular in the late 80s/early 90s, about when 8S drivetrains became widely available. If you just want the gearing, try to look for a 39t ring for your Zeus. Zeus can take down to 36t IIRC.

So if one BB is English and the other Italian I am out of luck? It isn't that great a loss, I just thought I could keep it going a lot longer this way without spending too much money. I wonder if Kuota's website has a spec on that.

Easy test--if your campy BB has the thread in the same direction on both cups or is marked 36 X 24, it's Italian. If there is a left thread cup and a right thread cup, it's English. It would be marked 1.37 X 24