Winter Maintenance.
 

I'm currently in the process of tearing down my road bike to the bare frame. As part of this I will be taking many of the components apart to re-grease bearings, remove grime, and make any needed adjustments. I will also be replacing some of the mismatched components so that I'm riding a complete group.

I personally installed all of the components new, straight from the box to the bike. So I know that they are complete and installed correctly. Since there seems to be much confusion about some of these components on the interwebs. I hope this I can help clear up some of these issues with vintage Campagnolo Corsa Record and Chorus (circa 1986-1988) components.

If there is anything that you have questions about or would like pictures, let me know and I'll try to help.

-Monkey-

Why did you install mixed components?

Aside from the front derailleurs and brake levers anyone should be able to easily tell the difference between Corsa Record (commonly referred to as C-Rec), Chorus, Atehna and Croce de Anue. The brake levers get a bit confusing because there were design changes, especially C-Rec since the originals lacked a QR in the lever. I believe all 4 groups shared the same shiftrs, being friction, Doppler and Synchro either one or two.

Now trying to pic from Victory and Triomphe.. that take a bit of skill.

Not Campy, but one of the first pieces I tore apart.
A set of Dia Compe Royal Gran Compe 400s, in white. All components in order from lower left to upper right.
QR and adjusting screw above, and brake pads in the lower left.
I'm pretty sure these are the original brake pads (probably a direct replacement of the originals). They are Dia Compe labeled.
The front and rear are the same, except for the length of the mounting bolt.

http://bikeforums.net/attachment.php...hmentid=421287

The remaining road grime is NOT original to this component.

It was a question of finances. I was in high school at the time, and budget didn't allow for a full Corsa group, so there was a mix of Corsa and C-record. Not that it really an issue, but I is all growed up now and want full Corsa.
There were somethings that never made sense to buy (SGR-1)... I am no more sensible, possibly less so as you may find.
Some of the confusion I see is that many people don't know all of the parts that go into the shifters. Many I have seen on eBay don't have all of the washers and may not function properly with out them.

Yes, if memory serves me, the "high art" groups (C, Chorus, CDA) all used the same shifters. Super Record still used the older design at the time.

The brake levers were/are still a bit confusing, with the QR in the lever, the micro adjust option in the lever, aero routing... I really have no idea which ones are correct. Campy was/is a confusing company and seemed to change specs on a whim.

As long as I'm stripping and cleaning I thought people might benefit from seeing these components up close and inside out.

SGR-1.

The internals. Springs and bits. I did not pull the spindles. This is where the grime likes to collect.
http://bikeforums.net/attachment.php...hmentid=421288

A little prying and that plate will pop up making easy to get a spot of grease in the rotational mechanism. The yellow spring controls release tension.
http://bikeforums.net/attachment.php...hmentid=421289

Exploded. You can see all of the parts I removed to fully clean and lube up the pedals (except for the spindles.).
http://bikeforums.net/attachment.php...hmentid=421290

Seat posts.

Not much to see here. You can se the difference between the top of the C-record pin (Left) and Chorus (right). C-record seems to be unique, CDA and Athena appear to me the same construction as the Chorus. These are the Aero profile. A standard model was also available with a circular cross section for the entire length of the pin.

http://bikeforums.net/attachment.php...hmentid=421296

Again from the bottom C-record (Left) and Chorus (right). A bit more to see. I have seen some eBay sellers confuse these, C-Record is the only one with an exposed binder bolt.
http://bikeforums.net/attachment.php...hmentid=421297

I always wanted a Corsa group.

The 1988 Chorus group was a far better buy than Corsa Record with a slant parallelogram and nice monoplaner calipers it was a gem.

I now have one! :) And shamelessly proud of it.
Early 1986-ish for the most part, including the Dopplers (I have an extra set of standard friction- mostly), M23, Electa, SGR, water bottles, Omega Strada Hardox to be woven over the C-record hubs, hub dustcap tool. Some a bit later, Delta gen-5. I have an extra set of later model derailleurs, A Merckx frame set and some other bits that I will be selling off at the end of this.
I have first year Chorus cranks, hubs, seat post, headset that I'll probably move to my currently naked Peugeot frame.
I don't have the Campy free wheel, only couple Regina Extra Superleggera and a couple Sach models.

~Monkey~

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.
http://bikeforums.net/attachment.php...hmentid=423082
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.
http://bikeforums.net/attachment.php...hmentid=423077
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.
http://bikeforums.net/attachment.php...hmentid=423078
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.
http://bikeforums.net/attachment.php...hmentid=423079

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.
http://bikeforums.net/attachment.php...hmentid=423080
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.
http://bikeforums.net/attachment.php...hmentid=423081

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~

I never realized that! That must be why I can't find chainwheels to fit my Chorus cranks they must all be Corsa!!

Corsa has the hidden fifth chainring bolt under the arm, where the pin is on the outer ring. All of the rings are 5 bolt. In the picture above of the two ring sets you can see that I lined up the pin, and the bolts are out of phase with respect to the pin/crank arm.

I have swapped my rings just to prove you can. Bolt Circle Diameter (BCD) is the critical measurement. Starting with the "High Art era" as I call it, Campy has used a 135 BCD. They still do. The major change was to move the two rings closer together. You should be able to mount modern rings on classic Chorus and Corsa cranks (depending on pin issues). (See also: Chainrings - Branford Bike - Seattle/Bellevue - Campagnolo Pro Shop)
Note that the latest (2015) models of Record have irregular bolt hole spacing - which won't work. But I think the lower lines and 2014 and earlier should be 135 BCD.
BCD is difficult to measure, but you can see from that link that the bolt center to bolt center is just under 8cm. Easy to measure.

Super Record (and other groups) of the '70s / '80s vintage have a different ring design (144 BCD)

I have a 42/53 set on Chorus, and currently a 42/50 on Corsa. I have a spare 39 around here somewhere. I'm hoping to get a 53 Corsa, but I'm waiting to see if I can get a good deal on the 'bay.
I have an Eddy Merckx bike with what looks like slightly later Chorus/Athena drive train (possibly 1992-ish). Looks like it might be a 39/53 set of rings. My friend currently has that machine, when I pick it up I'll be parting it out. If you are interested in the rings, let me know.
I also have a MTB at my parent's house with a complete 2014 Veloce 10x3 drive train, I'll check the BCD of the outer ring.

~Monkey~