My bike has 3 chain rings and I never use the largest one; I'm almost always on the middle one. Occasionally I'll use the smallest one when going up a hill but it's fairly flat here.
For the sake of understanding how this all works I was wondering if I could remove the largest chain ring. It seems to me that the main issue is how to fix the shifter so that it only uses 2 chain rings. Would I just fiddle with the limit screws and end up with extra (unused) click stops on the shifter? Or do I need to get a different shifter?