Shimano shifter compatibility question
 

I'm working on my first refurbish job, turning an old Schwinn Worldsport 14 speed into a 7 speed town bike for my 14 yo daughter. Most of it is pretty straightforward except that I need to change the shifter for the rear derailleur to either a twist or thumb shifter that will work with city bars instead of the drops currently on it. The label is gone from the read derailleur, but I have no reason to think it's not the original, and the current shifter is a stem-mounted index road shifter marked "Shimano 7-speed SIS."

So my question is, how specific do I need to be about compatibility on this? Will any 7-speed twist or thumb index shifter claiming Shimano compatibility work here? Or is it more specific than that? (Please don't tell me I have to replace the derailleur. I'm trying to keep this on the cheap.)

Thanks in advance.

If the shifter says SIS and works in an index setting then any 7sp shimano compatible shifter will work. But it isn't unheard of for earlier shifters to have a friction setting so it can do friction or indexed and in the friction setting will work with any derailleur. Does the shifter click when you shift or move smoothly.

Yep. It's a clicky index shifter alright. Funny thing, the front derailleur is friction. That's going to a single chainring, though, so it doesn't matter.

Not so funny, indexing is not much advantage when switching between 2 rings, and trim, if you need it, is built in.

Ah. That makes sense.

If it indexes then any shimano 7sp shifter should work. Going to single will solve any issues there. Sounds like a good plan, hope the bike and the work is appreciated.