Is a Shimano indexed shifter compatible with a non-indexed rd?
Iím setting up an 83 Schwann Letour Luxe as a townie for the bike library. I put some city bars on it and found a Shimano 6spd index/friction thumb shifter. My question isÖ is it possible to use the original pre-indexed 1983 Shimano Altus non-indexed r-derailleur with the shifter in indexed mode and have it effectively track a Shimano 6 spd freewheel.
1984 Miyata 310, 1989 Club Fuji, 1986 Schwinn Sierra, 2011 Jamis Quest, 1980 Peugeot TH8 Tandem
Since all the parts are Shimano and from the same era, it should work. I did a similar conversion, except I used a Shimano grip shifter and a Sun Tour deraileur. The shifting isn't perfect, but my daughter hasn't complained about it yet.
I think mechanically the thing that would make the old Altus less than ideal for this application is the fact that it won't have the built-in "play" in the upper pulley that a made-for-indexing rear derailleur would have. This built-in "play" in the upper pulley is one of the key innovations that made indexed shifting finally work decently-