Haven't used the EF-51's but I replaced the GripShifters on my Trek with a set of the EF-65's when I did a complete overhaul on it and I like them so much I just put a set on the rain bike I'm building from the TREK leftovers. If you are the slightest bit mechanically inclined hooking them up was a piece of cake and if you hit any stumbling blocks refer to Sheldon brown's website in the link 'Yo Spiff' posted.