I don't know if this has been posted before, but currently on one of the scooter boards, this is being discussed. I don't understand why a CVT is generally thought to be inefficient for mpg purposes on bikes and scooters, but if it is, could this possibly be a solution? I'm thinking a manually operated solenoid instead of a lever to facilitate changes. I think something like this could help anyone doing a foot forward design. Any thoughts?
http://www.pattakon.com/pattakonPatBox.htm
PatBox CVT (Continuously Variable Transmission) - Suzuki Burgman Forum