Originally Posted by
Bikehills1964
I am starting with a vintage pair of down tube shifters just to see how that works.
Friction doesn't care about speeds, road, mountain, but the cable drum on the shifter needs to be able to wrap enough cable to move the derailleur across the whole cassette.
Indexed shifters do care, so if you plan to someday move to indexed shifters the RD has to be compatible or shifters purchased to match the needs of the RD.