Hello gents, I would like to inquire about your automobile bikes. I have a mountain bike with 26 inch tires and an engine that red lines at 3600rpm and I would like the bike to have a top speed of 20 mph. OK with that data my question is would it be possible to have a sprocket attached to the engine shaft then have a chain run to a sprocket attached to the back wheel? I guess what I'm asking is if I did that would the sprockets be a normal size or would one of them have to be huge? Sorry if the question is hard to understand I'm new at this and it hurt just to think of what to say.