I am in the process of making a car boot buy lava dome into a low maintenance commuter for my sister in law and I reckon she'd find gripshift easier to get used to seeing as she's not ridden a bike for decades! Can anyone suggest which shifters might work well enough not to need replaced every 6 months? Shimano mechs, 3x7.
I don't know of any. Old gripshift from the days of 7/8 speed groupsets had a reputation for getting cack inside them. How about finding some old DX thumbshifters, they are uber-reliable.
I've replaced a few gripshift shifters with cheap £3.99 Sunrace thumbshifters bought from SJS Cycles. They need less hand strength to change gear, and you can see what gear you are in.
yup, Sunrace thumbies will last much longer than the cheap revoshifters.
Sachs Waveys if you can find any. They came in 7 and 8 speed and were dirt cheap and simple.