So why not harness that efficiency for other things? [Tony] had that same thought so he ordered a bike generator but after waiting too long for the company to send it, he decided to make his own.

You’re working to make the bike move, so why not make the bike work for you? If you’ve ever used a motor as a generator, then you can see where this is going. That’s the underlying principle ...

The bicycle generator: It's an eco-friendly marvel that turns your pedal power into electricity. But could this little gadget replace your power outlet and help you save on electricity bills?

Free Energy 100W Dynamo Bicycle Generator ...