I have a Campy Chorus double chainset of unknown age that is nowhere near new. I want to install in on my 1984 Trek frame. Obviously I need an English threaded BB, but on-line I see both 111 mm and 102 mm widths are flagged for Chorus use. How do I tell which one I need?

Road Fan

a picture of your crank would help. There have been a few cranks over the years to wear the Chorus badge.

Ok, I'll have to work on that tonight.

Typically with Record and Chorus, the 102mm is used for a double, and the 111 for a triple (both asymmetric and not interchangeable with Centaur and below). But my only experience is with recent vintage Campy square taper, and I don't know if the older stuff (say, pre-2000) is different.

102mm would be later model low profile cranks (mid 90s) so we need to see a picture .

ed rader

My first gen Chorus double crank used a 111mm, so a pic or date code from the back of the arm is needed

Ok, the left and right arms have 41 in a square on the backs, and I think I have a picture here:


The picture worked! I think this is an older Chorus. The cross-section of the arm is similar to that of my C-record, and very different from my recent 10-speed Record.

Road Fan

first gen 1988 = 111mm

Symmetrical? Assymmetrical? were they cup and cone, or integrated? What today is a good replacement? AC-H is available in a 111 ...

Metaluna, I think you're saying than 111 BBs for Centaur and below, for example an ACH 111, are assymmetrical. You also know that they are not suitable for current Chorus triples, but you don't know if they are suitable for 1st gen Chorus - am I getting this right?

And Vpiuva, thank you for the help! Are you saying that you think that any Campy 111 will work right, or do you think there are other critical characteristics?