I have a 1963 Ural sidecar bike that I'm converting. I'm documenting the process at http://itya.blogspot.com/
. It's heavy. I've removed the engine but it's still ~500 pounds. With batteries and motor, it seems like it will probably get up over 1000 pounds. Add two people and a dog or some cargo, and we're looking at moving up to 1500 pounds. The sidecar is made of pretty thick metal, so I'm thinking I might cut out some pieces of panel and replace them with fiberglass or something, while leaving the frame in tact of course. Also, the bike is originally shaft-driven, so changing to chain-driven would simplify the overall design and drop some weight, but might be difficult to accomplish. What do you think? Should I switch from shaft to chain? How much work do you think it would be?