There are another solutions too, not only the hub motors! Check out this two ideas!
This “pedal engine” concepts is more than two years old, developed by Stephen Britt. He won with it a 50.000 USD contest too. Unfortunately we didn’t hear about this product later on, but this drive train is really interesting. You can simply replace your bicycle pedal with this one, which includes the battery the sensor and the motor too. The range is 15 km, the maximum power is 200W. If you flip the pedal over, the engine starts running. The sensor measured the pedal force, so this prototype was really awesome!
The second product I show you is a brand new product from Protanium, which will be announced on the Eurobike fair. (Our earlier post about the hidden battery of Protanium is here.) They use shaft drive instead of the chain. The lower efficiency of this drive train is compensated by the electric engine, which delivers maximum 540W and 63Nm from a normal motor of 36V 250W. The sensors are optical; and they measure both the torque and the speed of the bike. Read the announcement of the company!
We are really excited to see this…