- BMW files patent for shaft-driven electric bike
- Designed to offer more flexibility and compactness
- Could be used on the upcoming large electric motorcycles
BMW has registered a patent for a shaft-driven electric motorcycle. The patent shows a longitudinally mounted motor with an intermediate shaft and CV joints at each end. This development is carried out to offer more flexibility and compactness in design. The brand might employ this design on its upcoming large electric motorcycle lineup.
With this design, it is possible to move the motor forward or backward, up and down or side to side. This kind of layout is difficult to achieve with a transverse motor method. This layout, therefore, offers more freedom to the designer while styling, battery placement and gearbox placement, increasing the power to weight ratio of the motorcycle.
In the conventional layout, the motor is mounted ahead of the swingarm which further drives the gearbox and then power is taken to the rear wheel via a final belt. But with the latest developments, BMW has managed to incorporate a planetary gear set mounted behind the motor which reduces the output shaft speed while keeping the gearset inline.
In 2019 BMW also unveiled the Vision DC Roadster. The electric motorcycle concept was mounted with a shaft drive for final transmission instead of a belt or chain drive. The battery pack was placed vertically and in place of the boxer twin engine cooling, ribs were mounted. However, the concept didn't make it to the production model.
