Campag 8 speed long cage rear mech

[regoak]

I have just purchased one of these on Ebay with the intention of using it on a 5mm spaced shimano 7 cassette, plus campag 8 speed ergos. I recieved the mech and although it is NOS, felt like sending it back as the cage appeared to be bent, or at least curved.
I contacted the seller in Germany, and he replyed that he was originally confused when he saw the cage on another Campag 8 mech. He did find though it was a design feature and sent me a photograph of 3 other Campag mechs with the same curved cage.

Has anyone else found this?

[tatanab]

They are all like that guv.

Yes, when the mech is mounted on a frame, the jockey cage is not vertical but is canted slightly towards the wheel. I have 3 medium cage and 1 long cage in use at the moment and they really are like that. I cannot say that I ever noticed when the mech was on the table, but when riding, if you look back at the rear mech the shape is obvious.

[regoak]

Thanks for that. I wonder if Ernst Campagnolo had been on the Vino before he sat down at the drawing board to design the early long cage mechs.

[tatanab]

I've no first hand experience of early long cage mechs, meaning 1960s and so on they were way too expensive for me at that time. The cant I've described is also present on 9 speed mechs I've had so must be a design feature. I've just had a look at a 10 speed I have and that appears to be vertical, although it is hard to tell with the machines hanging in the shed, much easier when riding.

I recall something I read on the web about straightening gear hangers, and it said that not all gear mechs have vertical jockey cages.

[regoak]

Yup. you are right. I have just looked at the Veloce 9 speed mech I have on another bike, and it too is "bent". Though not as markedly as the 8 speed mech I was querying originally.
I have just screwed the 8 speed mech on a frame and the top pulley does seem to be as near as poss right angles to the hub axis, so it should work OK.

[regoak]

That settles it, Sheldon Brown on the bit about checking if a deraileur is bent mentions the Campag curve http://sheldonbrown.com/derailer-adjustment.html .

[Brucey]

I believe the idea is that the downshift is more likely to occurr without the chain chattering against the next largest sprocket after the shift is complete.

IIRC an early Shimano index set-up SI techdoc suggested that the pulley cage should be vertical, but a small error in one direction (lower pulley outwards) was permissible, unlike an error in the reverse direction. Likewise a small 'toe' setting angle was OK in one direction only.

Sounds like Campagnolo built this into the mech, rather than tweaking the frame to suit.

cheers

[regoak]

I have now got hold of some campag 8 speed ergo levers and got a nice indexed system working on a shimano 7 speed cassette.
I had to fit a much longer bottom gear limit screw on the mech to prevent over enthusiastic geaar changes going into the spokes.

[Big T]

It is possible to use a 9-speed rear mech. My wife has this set up on her winter bike. 7 speed shimano cassette, 8 speed campag ergo's and 9 speed Xenon rear mech. you do have to use a 9 speed chain. Works perfectly.