Today I have some Corsa / Cchorus Cranks and BB info to share. Especially for you weekend warrior wrench wranglers that want to do your own work.

Chorus dog bone (non-drive side crank) on the and C-Record on the right. Both with their respective mounting bolts. My chorus cranks are 170 mm, and the Corsa are 172.5 mm. 2.5 mm difference ain't much too look at.

First generation Chorus had a bolt and dust cap, later generations got the same self extractors as C-Record and CDA.
Also included is the Campy Peanut Butter wrench - which is required to remove the Choru bolts. Standard sockets have a thicker wall that won't fit into the space of the crank arms.
At the time, the big deal about the Chorus cranks was the arches. The arms are also slightly thinner and narrower.

Next are the Bottom Bracket spindles. Once installed, Chorus and Corsa are effectively the same, you can mount Chorus cranks on a Corsa BB and visa-versa. But notice the cones. The Chorus (top, etched 68-SS) is a bit wider that the Corsa cones (bottom, etched 68-SP) You will need the proper fixed and adjusting races for each.

The overall spindle length is the same on both.

And the Spider arms. Obviously, Corsa is the notorious 4-legged spider, and Chorus is the five legged spider.
Pictured with the Campy extractor tool in place on both.

A note about extractors. Chorus (with duct caps) is right hand threaded. The self extractors are left hand threaded. So you need the respective tool for each. Trying to use the RH tool on self extractor cracks won't work at best, and you could damage the thread if you try. I also have the Park extractor that one of my LBSs sold me to remove the Chorus cranks. It doesn't fit. It goes in about 2 thread and binds. You must have the tool completely seated or it will damage your cranks. What's nice about the campy tools is the not only are the mounting threads handed, but so are the extracting threads. So you can identify the RH from the LH tool by spinning the extractor. (they are etched with a part number, but it's difficult to read if the lighting isn't perfect).

Not much to say about the rings. They are nearly identical, except for the big (outer) rings. Chorus has the inter-nodal pin, and Corsa has the nodal pin. The small (inner) rings are identical.


Tools. The two extractors and peanut butter wrench. You really must have the Campy versions of each. They are available on eBay, but pricy for tools. I use standard Park BB tools for BBs headsets and pedal (set of three wrenches cover all three uses).
Also in the picture is the original bag and instructions sheet (dated 12/2008) for the RH extractor. If you read the instructions it becomes clear that they really say nothing - just legalese. There is a wee bit of technique required to use the extractor. Post if you want my input.

I would recommend using the extraction tools instead of the self extractors. The previous owner of my Corsa cranks seemed to have used the self extractors, and is looks like it beat up the mounting bolts a bit.

Finally for tonight, a quick look at the BB. You can see the difference in finish between the Chorus and Corsa cups. Corsa having a high polish. You can also see how wrenching surfaces get deformed. I have more to say on BBs but I'll leave that for later.


I hope this answers some questions that some of you home mechanics may have about working on your vintage Campy machines. If any one is in the south eastern PA area (and possibly southern New Jersey) and needs to pull you Campy cranks, and don't want to spend the money on the tools, let me know, I might be able to help.

~Monkey~