Bicycle Question?

Question

I am trying to put a motor on my bicycle. It is a chainsaw motor. My question is about the gear ratio. I hear that it is supposed to be a 12-1 ratio. But it doesnt make sense. Can't I just take 2 sprockets from the bike and weld one on the chainsaw engine, and have the other on the back wheel? If it works when you pedal the bike, why wouldnt it work with the engine? The engine is only going to make it a bit faster than what it was when I would bike with my legs. I hope it is easy to understand what my problem is. Any ideas?

Answer 1

yes, you can do that, but the 12:1 ratio is probably the best for torque and speed. a higher ratio would make it slower but more powerful, and a lower one would make it fast but with less torque