[ame]http://www.youtube.com/watch?v=sGTB_uZdw0o[/ame]
Now this is what I call a Bike! Top speed is 60 MPH. The acceleration is unmatched. The rider is often challenged by cars for a race and never been beat. 15 horsepower max Briggs and Stratton motor running at 48V. In this video we compare it to a performance moped.
I should have shot video of my 48v Razor pocket bike. 
6 batteries and a curtis as well as a larger motor. It was TOO fast.
I would not trust that chain to be safe. I have had alot of bikes and motorcycles in my day. Look at the difference in size, a bike chain is so small and i have had them break just riding a mountain bike. Then look at a motorcycle chain , they are 5-8 times the size able to handle to tork and stretching.
Just something to think about. Cool project but when that chain breaks I wouldn’t want to be on that thing.
A motorcycle is alot heavier with alot more power. If a crank arm on a bike is ~10" long and a rider is 170lbs that’s 141lb/ft of torque. Put that thru a 4" sprocket and you have 420lbs of pull on the chain. I’m pulling numbers out of the air and I don’t guarantee my math. =) Plus don’t have a crank to measure. Anyways, the chain on a bike is pretty damn strong. Quite capable of flipping the bike.
What is the torque rating on those briggs motors?
[QUOTE=EvForum;1951]I would not trust that chain to be safe. I have had alot of bikes and motorcycles in my day. Look at the difference in size, a bike chain is so small and i have had them break just riding a mountain bike. Then look at a motorcycle chain , they are 5-8 times the size able to handle to tork and stretching.
Just something to think about. Cool project but when that chain breaks I wouldn’t want to be on that thing.[/QUOTE]
i’ll beef up the chain then 
either way… it would be one hell of a way to get to and from work in a short period of time.
I can see you losing a leg or your life if you’re not careful. I’d have a substantial guard fabricated to enclose the entire chain set. If is breaks it will rip your skin like paper and possibly throw you off on your head!
BE CAREFUL! But I like the idea a lot!