I finally got around to installing my shift kit from Sick Bike Parts , and I must say it adds a whole new relam to motor biking. I put my motor and kit on an old ten speed touring bicylce, with back sprockets from 14 to 28 teeth which gives me a nice choice of riding ranges. The bike has 1 3/8's X 26" wheels which makes for smooth rolling resistance. I was surprized to see how well my bike climbed up a steep hill in Fremont , CA. , and I weigh the better part of 225. Jim has been very helpful with the few technical questions I had about the installation. Now when I go riding its nice to know that if I want to go faster than 15 mph I don't have to deal with the high rpm's and vibration plus the fun of shifting makes for a more interesting ride. Learning to start the motor from a pedal startup is a little tricky at first, but it is a skill you quickly master as long as your motor is in a good tuned up state. For the first time I can truly tell someone that my bike will really go 35 mph, although I rarely take it passed 28 mph. If anybody has any question about the shift kit's proformance feel free to ask. Macon