BMW drive unit swing arm concept in production
E-bike with BMW swingarm hints at firm's electric direction
BMW has unveiled a new high-tech rear suspension system for a mountain bike which could be used as a blueprint for lightweight electric bikes of the future.
The system puts the rear swing-arm and pedals into one module, which is then attached to the frame. Without the constraints of having to design a frame to include the pedals, different, innovative frame designs can be used.
It also means a drive chain or belt could operate without tensioner and much greater suspension travel can be allowed compared to a conventional mountain bike.
BMW has patented the system and it is now in production with specialist bike manufacturer HNF Heisenberg, which is based near Berlin. HNF specialises in ebikes and the BMW system will be used on a high-spec mountain bike called the Heisenberg XF1. The bike uses an electric motor to provide assistance to the rider.
HNF is using a belt drive with hub gears. The system has allowed them to build a bike with a stiffer frame, increased suspension travel, no recoil through the pedals over rough ground and improved grip due to better suspension control of the rear wheel.
It means you'll be able to pedal smoothly even over very rough ground.
BMW has no immediate plans to use the system on any of its own products.
