Thanks, Harry, for pointing out the obvious! I just used the Index of Ratio calculator. Looks like changing my rear sprocket one tooth nets 1 mph, so that's easy to remember. The 48t will be a good choice giving me 34 mph at 5000 rpm, a good cruising speed, and 54 mph at 8000 rpm. Who needs a transmission with a ton of torque?Im probably pointing out the obvious..... but there is a calculator in the DIY section..... its the first thread