While I haven't researched this idea too much, I saw a couple of videos on youtube about people generating around 300 watts with alternators connected to bikes. So, my idea was, instead of running a regular drivetrain with chain to wheel, I'd thought I'd just use an electric motor (probably a hub motor) and run the chain to the alternator...

I have a spare alternator kicking around as well as an inverter. The bike itself will be a ground up build, frame and everything... ATM I'm not too concerned about weight, as much as I am about the possibility of it working at all..

Thanks for the reply .