What if there was a way to hook up a small sprocket on to one of the friction drive generators and place it in a way the the chain spins it along with the rear wheel. Then would you be able to take the power you get from the generator to charge a small battery given the output is high enough to do so. Thus allowing you to run a self sufficient electrical system. Not sure if this would work just an idea let me know of any knowledge or info you have i been searching the post nothing quiet like this.