What thread bottom bracket for 1980's Colnago Super?
 

I want to change the cranks on my bike frame to a Campagnolo crankset but there are so many crank sizes I don't know what to look for or what I'm looking for. I'm NOT trying to "flip" the bike, I just want to be happier with the bike. Thanks.

http://i.imgur.com/hpklBWqh.jpg

It should say on the side of your existing BB. But, every Colnago I've found uses the 36x24 Italian threading.

Could use some derailleurs....

Thank you very much, this small piece helped a lot.

It looks like a lot of the newer Campy are using a hexagonal shape instead of a square.

If I wanted to use a newer crank, I'd have to replace the BB -- but all the 36x24BB's are square taper. I don't have to replace the BB -- I can just replace the Sugino cranks with square taper Campy from a former year.

The old Campy groupo's I'm seeing are around $400+ and I'm afraid I'd have to pay even more for a rear wheel. That's more than I paid for the bike to begin with.

You should be able to put pretty much any Campy crankset you want on it you will just need to get the matching Italian threaded BB for the crank you choose and the correct speced length for SS/FG or Double depending on the setup you choose. The length and spindle type ISO or Campy depending on the crank set for most of the Campy Cranks may work but won't be a good match with the JIS spindle BB likely with offset currently on the bike.

Not easily. BBs have 4 measurements, the cup threading, spindle length and offset i.e. one side protrudes more than the other, and taper length/angle

Most older Campi (pre 1990ish) BBs used a right/drive side offset and to the best of my knowledge all Campi square BBs/cranks used a taper different from Sugino,Shipmano, Omega etc.

In general you need to decided the brand, model and even year of Crank then find the matching BB with the correct threading for your frame.

Buying the BB first is almost like buying a crankshaft and then finding the engine to go with it.

Just when I thought it was going to be simple -- it's gotten more confusing hah... Thanks for explaining and sorry this one's not a Bianchi. : )

Are you leaving as a single speed? A Campy Pista crank will run some coin. Yes the BB will be Italian thread (36x24 , 70 mm) but beyond that, as noted, you'll need to decide what crank you want then you'll get better advice on the actual bb to use.

A side note - I just got a modern Colnago EPS and the bottom bracket is English thread. First time I've run across that on a Colnago and I think a little piece of me died. That just ain't right.