My dad has employed me to fix up a few family bikes we have so he know who needs a new bike and such stuff. Right now I'm working on a bike for my mom. It's and older Trek Antelope with Shimano Exage shifting, actuated by thumb shifters. The thumbies are hard to use though, and the integrated brake levers are crap. My plan is to switch to Gripshifters, I think that they will work better for my mom. Plus I'll be able to swap brake levers. Will lowend Gripshifters(SRAM or Sunrace) work with Exage? Shifting doesn't have to be superb, but I don't want to spend money if it hands down won't work.