Been reading here for awhile, so I decided to join in. I picked up 2 Zip Cycle friction drives a few months ago. I have really enjoyed tinkering and riding but, They are slow. I am thinking about selling one and building up another bike with a nice Sachs 4 hp 2 cycle engine I have. I will post more as I figure out what route to take with my build. Later, Milo. P.S. There are some great motorbikes on this forum.