These Shimano STI M020 Rapid Fire 7 sp, ST200 group, came on the 1990 Giant mtb I picked up last fall. The question is - what is the shifting sequence? Seems a little erratic (assume I'll change the cables/housings. I did a semi - dissassembly and clean/lube of the cables, derailleurs and shifters last fall but I think I need to lube and clean better.)
On the rear cogs I can shift to larger cogs one at a time if I'm careful, other wise I can pull it up about 4 cogs in one stroke, then the next full stroke I can shift to the very largest cog.
On the front Biopace triple, I can drop to the smallest gear in a single hard release of the trigger, or if careful, just release the trigger less aggressively and just drop from the largest to middle chainring.
For reference here is what they look like. Seems to be a hundred different styles of the same name.
Shimano ST M020 Rapid Fire 7 sp.jpg