Replacing Gripshift with SRAM SX-4 rear Derailleur
My mom bought a new bike, and despite my recommendations, bought one that had gripshift. 2 weeks later she doesn't like gripshift and wants it replaced. The rear derailleur is SRAM SX-4 (system is 8-speed), and the front derailleur is a shimano nexave (it's a triple).
Absolute best case would be to get a rapid-fire style shifters onto the bike. Can anyone tell me what parts might be compatible?
My fall back position is to get some thumb-lever style friction shifters, and retrofit those. If you have advice on readily available or particularly desireable models for that option those tips would be appreciated as well.
thanks for any help/advice you can provide.