New “bike-by-wire” system for e-bikes

An automated drive system for e-bicycles does away with the chain drive and substitutes an electronic system

Spotted: Fly-by-wire platforms are computer-regulated systems used as an electronic interface in aircrafts. They are designed to stabilise the aircraft automatically and adjust the flying characteristics without the pilot’s involvement, but also to give the pilot a tactile feel for how the aircraft is handling. Now, German automotive manufacturer Schaeffler has developed a “bike-by-wire” system dubbed Free Drive, that is designed for ebikes. 

The Free Drive was developed in partnership with two-wheel electric drive specialist Heinzmann. It is a hybrid drive that does away with the need to have the pedals mechanically linked to the rear wheel, replacing a chain or belt drive with electrical wiring. The system consists of four main parts: a pedal generator, a 250-watt drive motor, a lithium battery powerpack, and a handlebar-mounted “human-machine-interface,” or control unit. 

As the rider pedals, they spin the generator, which converts mechanical energy into electrical energy and feeds this to the wheel hub motor. That motor converts the electrical energy back into mechanical energy, and uses it to turn the wheel. When the rider pedals harder than necessary, the extra energy is stored up in the battery. The control unit improves efficiency by allowing the system components to communicate with each other. 

Another benefit of the Free Drive system is that it can be adapted for different applications, explains Dr. Jochen Schröder, President of Schaeffler’s E-Mobility Division. “Regardless of whether the system is used in 2-, 3-, or 4-wheel applications, the absence of a mechanical connection between the generator and motor means that Free Drive can provide maximum flexibility in the bicycle architecture and a freely configurable pedalling sensation, which is tailored to the requirements of the bicycle and the needs of the rider, while ensuring minimal wear.” 

As people increasingly seek to reduce their carbon footprint and also get some exercise and fresh air, bicycling has seen a huge resurgence. This has been reflected in the number of innovations aimed at making riding safer and easier. Adaptations covered recently here at Springwise include a customisable, modular e-cargo bike and 3D-printed bike frames. 

Explore more: Sustainability