Originally Posted by
Retro Grouch
Assuming those shifters have a friction function, set them on that and they'll work. You'll just have to sense when the chain moves to the next gear. There are a number of riders who prefer friction to indexed click shifting systems....
This. All my bikes but one are friction, because that's what I learned on and it's not worth the trouble and expense of switching. The difficulty of shifting a non-indexed driveline has been WAY overestimated.