Originally Posted by
Lascauxcaveman
Every RD I've ever used with an 8-speed hub could handle the range, using friction shifting. Including the Campy Nuovo Gran Sport, Nuovo Record, C-Record, Croce d'Aune and Rally (1st gen). As well as all the Shimano, Simplex, SRAM and Suntour ones I've tried. I think almost any Rd made in the last 50 years can be made to work over 8 cogs, using friction shifting. Campy or otherwise. If indexing, well, that is another story.
In my experience, maximum cog size is a much more important limiter than number of cogs.
One concern regarding cog count is that with increasing cog numbers the large one often gets close to the spokes. The older, freewheel assumed, ders can have rather thick cage plates, pulleys that are wide and can catch on the spokes if not careful. If someone needs to ask questions about basic der capacities they might not be aware of the cage/spoke clearance issue until too late. Andy.