Hi, my names michael, I work at a bike repair place in downtown valdosta georgia, and saw some guy come in with a motorized bike and I helped change his tube out. I thought it was a really cool, especially because I love motorcycles so much (but mine broke down). Anyways, I have been reading random posts trying to figure some stuff out for myself, and im curious, do you have to have a free wheel or will a single speed bike work fine? I havent picked out a kit yet, looking to spend around 400. Im thinking about a two-stroke, I want a good sized engine because im mostly going to be away from traffic in the country and I would like something fast. I would appreciate any input or help. thanks!