propeller propulsion bike
The key motivation behind this project was to use a combustion engine to power a regular bicycle without using any drivetrain. With propeller propulsion we could avoid the use of any complicated mechanical transmission mechanism. Even though the efficiency of the propeller propulsion is substantially less than gear drives, we measured very favorable fuel consumption because the motor operates around the optimal ~3000 rpm/min without much fluctuation. On 100km range it consumes 2.33l gasoline*. The maximum velocity is up to 50-60 km/h.
an article in the local newspaper (in hungarian):
*depending on the wind:)