Any Real Differences in Campy Short cage RD?

[Ralph]

I have a short cage Centaur 9 RD and a short cage Chorus 10 RD. Both look the same dimension wise....distance between pulley's, etc. Both say C9 C10 on pulley wheels.

But in the instruction booklet that came with the Chorus 10 RD, the Centaur 9 shows higher capacity....both in teeth it wraps up and in size of max rear cog. Is this so, or just different advertising? Is the Centaur likely to work in a situation where the Chorus might not? I notice same for the Veloce and lower levels in same little booklet that comes with the rear derailleurs.

[oldpotatoe]

I have a short cage Centaur 9 RD and a short cage Chorus 10 RD. Both look the same dimension wise....distance between pulley's, etc. Both say C9 C10 on pulley wheels.

But in the instruction booklet that came with the Chorus 10 RD, the Centaur 9 shows higher capacity....both in teeth it wraps up and in size of max rear cog. Is this so, or just different advertising? Is the Centaur likely to work in a situation where the Chorus might not? I notice same for the Veloce and lower levels in same little booklet that comes with the rear derailleurs.

No, use either on most any combo w/o problem, even a compact and 13-29 or even a standard and 13/29 as long as the chain is sized properly. AND use that '9s' with 10s ERGO and the '10s' RD with 9s ERGO. There is much more inter-compatibility w/i Campagnolo that you will read from Campagnolo or see on the 'web'.

[Dave]

All Campy short cage RDs have the same 56mm cage length, so there should be no difference in the true wrap capacity or max cog size. Campy sometimes listed the wrap capacity to match what they sold at the time. Before compact cranks, they offered a 53/39 with a 13-26, which is 27T of wrap, so that was the advertised capacity. To use a 13-29 cassette, a medium cage length (72mm) was recommended. Once compacts came out, an additional 2T of wrap was needed. The short cage RD was not changed, but was advertised as compatible with cranks creating 2T more wrap.

The only exception to this rule is the 2010 11 speed RDs. A change was made to the "B" screw mechanism, so a short cage RD can now handle a 12-29 cassette. AFAIK, the cage length was not increased, but I've never read a posting from anyone who owns one and measured it.

[keevon]

Only thing to note is that pre-2001 Campagnolo 9-speed had a different cable pull than post-2001 9-speed and 10-speed. Theoretically, you can't mix pre-2001 with post-2001.

EDIT: But Centaur 9 speed came out after 2001, so never mind...

[oldpotatoe]

All Campy short cage RDs have the same 56mm cage length, so there should be no difference in the true wrap capacity or max cog size. Campy sometimes listed the wrap capacity to match what they sold at the time. Before compact cranks, they offered a 53/39 with a 13-26, which is 27T of wrap, so that was the advertised capacity. To use a 13-29 cassette, a medium cage length (72mm) was recommended. Once compacts came out, and additional 2T of wrap was needed. The short cage RD was not changed, but was advertised as compatible with cranks creating 2T more wrap.

The only exception to this rule is the 2010 11 speed RDs. A change was made to the "B" screw mechanism, so a short cage RD can now handle a 12-29 cassette. AFAIK, the cage length was not increased, but I've never read a posting from anyone who owns one and measured it.

I have a 2009 Super Record RD(pre 12-29) and an Athena RD and the dimensions of the RD are the same...with the exception of where the spring is inserted at the 'b limit' screw.

[oldpotatoe]

Only thing to note is that pre-2001 Campagnolo 9-speed had a different cable pull than post-2001 9-speed and 10-speed. Theoretically, you can't mix pre-2001 with post-2001.

As I mentioned previously, I use 'modern', as in 2009/2010 Rear derailleurs, with older Campagnolo shifting systems and installed modern, post 2001 ERGO using older pre 2001 RDers with great success. I just installed a 2010 Veloce RD onto a guys 1994 8s ERGO and it worked like a charm without any modifications needed. It's not a big deal as long as the RD isn't worn out.

[Ralph]

The 9 speed is a late version. As I mentioned in a previous post, I'm building up a custom Jonathan Greene frame with Campy 10 speed. 39-50 front, and ability to run either 13-26 or 13-29....I have both cassettes. I also have a new Centaur Mid cage derailleur and the two short cages mentioned above.

My daily rider is a 9 speed Cannondale CAAD 5 with a 14-28 in rear, and it has a short drop out tab (I wonder if my LBS has a longer tab that would fit....either generic or C dale), requiring use of a mid cage. My new steel bike has a longer tab, so I believe I can use a short cage RD. I'm done with my spring traveling now, so can stay home a while and finish up this project. I don't mind buying new parts if necessay, but also hate to buy stuff I don't need. My parts box, from 35 years of cycling, is full enough now of old useless stuff.

BTW....I recently bought a new Honda Element to travel with and haul my bikes and stuff. For it's price (relatively cheap), it sure does a good job, gets about 27-28 MPG on long 600 mile days. It's not very aero, and that hurts economy, but it sure hauls more than many realize....bikes upright inside etc. Fork mounted on bike tights. Good strong tie down points. I'm not going across country, or way North with bikes on outside. My wife thinks the Element is kinda crude, compared to our other vehicles, but that is part of it's appeal to me.