[Patrick]

Those HXT outrunners at Hobbycity look like they could work well. The site says it replaces a 60-80cc engine. A lot of pocket bikes use 49cc engines and can push you to the 40mph area with one speed, so that outrunner should do ok.

I'd like to see an electric pit bike, but use the original transmission and sit the motor where the crank of the engine would usually be. I would look more professional than some of the custom e-bike around and it can't hurt to have multiple gears.

I've always thought about an electric push bike with the batteries inside the frame. Makes it look a lot neater than a brick hanging off the side.