There was a really beautifully made Gian Robert derailleur set in the early sixties. Every piece of the rear derailleur is a little casting with a mirror chrome finish. Nearly every piece has Gian's name on it. The wheels are steel with ball bearings and the parallelogram has two springs. Unfortunately it's rather underengineered. The rear won't wrap much chain, and the front looks like the cage would break off with the first shift. It's a beautiful, delicate piece of jewelery, but not something to use on a bike. There's a drawing of it on p. 180 of the Dancing Chain.
Oscar Juner once told me that Gian Robert designed the original Campy parallelogram derailleur. Can anyone confirm this?
Leonard Bulger
Ann Arnor, MI
4 deg an hour ago, a toasty 10 deg now