I've got an opportunity to buy one of these, similar to this one
Does anyone know much about them? Would I be able to use this with a modern rear wheel, if I use friction downtube shifters? So the old mechs have much less movement range than modern ones?
I have a Suntour Cyclone derailleur that's about 23 years old. It was designed to shift 6 freewheel cogs. It will shift 8 cogs on a 9 speed Shimano cassette. It is the limitation of the derailleur movement and not cable pull.
My Simplex downtube shifters will shift across all 9 with a modern deraileur.
I also have an old 1973? Campagnolo Valentino Extra derailleur but I have not tried it on a 9 speed cassette yet.