I would imagine that it would mostly be me riding. It might seem like a hassle or waste to motorize a tandem if others aren't going to ride it most of the time, but I wanted the option at least to give my friends rides. I don't mind if it's not very fast with an extra person, I just want something to assist getting up hills and coasting across flat stretches. This is my first build, and it will probably be a small summer project, so don't wanna go too big with the engine. Besides, with the laws as they are, I don't really wanna think about motorcycle licensing or registration.
That said, I'm wondering how difficult it will be to mount a frame engine on a rear rack? I think it's possible, but I certainly don't know the easiest way