This set is designed so that you can run a 20x3.0 on the rear and a 24 inch tire on the front. Great for turning chopper bikes into three speeds! Upgrading your bike to an Inter-3 is very simple. Switch your wheels, mount the grip shifter to the handle bar and attach the cable. That's it! Or, take it to your local bike shop. Most shops will mount your kit for a reasonable charge.