Is the square taper of 2005 Chorus the same as the old?
 

I'm still totally confused by all the different BB/Crank combinations. I have a Zeus BB and crank on my 1981 Davidson, and I have a 2005 Chorus/BB to use on it if I want. The Zeus is a Campy compatible copy from the time. While they are both English thread, and therefore I could swap the BB, can I use the new crank on the old BB without doing the BB? My main reason for wanting to swap is the somewhat lower 39 tooth small ring. The Zeus has a 52/42, the Campy 53/39. Also, I use a 10speed chain and the narrower teeth of the Campy would be a little less noisy.

I had read in a thread that the newer square taper BBs use the JIS standard, and the old ones were a different standard.

I believe that Campagnolo used ISO square tapers only until they changed over to the new outboard bearings.

Campy has always used an ISO square taper.

I guess I can give it a try. There's lots of winter left to think about this.