If you can locate a small generator that runs on gas, and, if you have the mechanical skills required to take it apart, you will probably see a shaft on the generator-side of the unit which connects to the motor side of it.
From that shaft, you would be able to attach a bicycle sprocket to it. Now, comes the hard part. You will need metal-working skills and tools to fabricate a mount for the generator portion to attach to the bike-frame.
A side note: The kind of generator that you would want to use is one that runs on around 1/4 horse power - anything more than that and you would have too much difficulty spinning your legs fast enough to actually generate any power.
A better choice would be to use renewable-energy to run the generator - like a steady flowing stream of water.
From that shaft, you would be able to attach a bicycle sprocket to it. Now, comes the hard part. You will need metal-working skills and tools to fabricate a mount for the generator portion to attach to the bike-frame.
A side note: The kind of generator that you would want to use is one that runs on around 1/4 horse power - anything more than that and you would have too much difficulty spinning your legs fast enough to actually generate any power.
A better choice would be to use renewable-energy to run the generator - like a steady flowing stream of water.