Hello, I am looking to build a motorized bike. I was given the idea by a neighbor who built one on a huffy cruiser bike that uses coaster brakes. I was planning on doing this but I was wondering if they were safe. I did some research but I haven't found a definitive answer. Another factor is that I would have to find a cruiser bike that has hand brakes. If it isn't safe, are there any bikes that aren't too expensive that would work well for building a bike?