On the occasion of the Eurobike trade fair which is being held in Germany until September 4, the company Schaeffler presented a transmission system for electric bikes without chain or belt. Called Free Drive, it uses the technical principle of electrical control systems by CAN bus widely used in theautomobile.
© Schaeffler
The kit consists of a generator integrated in the crankset, a 250W motor in the rear hub, a batterie lithium-ion and a handlebar control module. When pedaling, the generator converts theenergy mechanical in Electric power which is transmitted by cable to the motor. The generator adapts the resistance depending on the pedaling effort. The excess energy produced during pedaling is stored in the battery which is also supplied by a system of braking energy recovery integrated into the motor. Besides the electric bikes, the Free Drive could also propel tricycles or quadricycles, specified the manufacturer.
However, questioned by the site ElectrekSchaeffler recognized that the Free Drive is about 5% less efficient than a chain drive when it comes to converting the rider’s pedaling power.
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