Rear Drive

  • The Rear Drive mounts to the "non-drive side" of the bicycle to allow the user to freely pedal the bike

  • The bike's disc rotor mounts are used to mount the Rear Drive to the rear wheel

  • 6 spokes bend around the brake caliper, and mount the rear sprocket

  • Taking existing geometry from the bike, and creating the geometry of the spokes proved to be a challenge, but after 2 3D printed prototype iterations, the spokes fit between the brake caliper and the bike spokes.


Spoke FEA Study

  • The spokes are long and thin, and need to be strong enough to support the large loads from the motor

  • Using specs from the motor manufacturers website, FEA analysis shows that the spoke will not fail under the motor's maximum torque (59 N-m)

Rear Drive Prototypes

"Rotor Mount Left" Uses the 6 bolt disc brake mounts, and protrudes through the rotor

The spoke attaches to "Rotor Mount Right" on the inner side of the rotor

There is about 0.3 inches between the brake caliper and the bike spokes, the "Spoke" must fit between these constraints

The 120T rear sprocket will be mounted to 6 of these Spokes, and a #25 chain will connect the "Front Drive" to the "Rear Drive"