When I was a senior in high school, I wanted to buy a motorcycle to ride on the farm. My parents weren't exactly thrilled by the idea, so instead of buying one outright I decided to build one from the ground up. I used a free copy of google sketchup to design the motorcycle from scratch, and then I started buying go kart parts. The bike has 22" diameter, 12" wide balloon tires and handles muddy situations quite well. It has a 16 hp, 400 cc engine with a simple centripetal clutch that provides a fair amount of torque. Apart from the axles which I had to have machined, the whole motorcycle was constructed with a chop saw, an angle grinder, and a stick welder. Variations exist from model to finished product from last minute decisions in the garage. Some serious damage has occurred, thus requiring a few rebuilds. Personally, I've only been thrown off twice.