Niederer, Johannes Martin Gabriel

A sensor unit 1 for detecting an external power input to an electric drivetrain ED of an e-bike is proposed. The sensor unit 1 comprises a first element 100 being coupled or couplable to an electric motor power output unit 10 and a second element 200 being coupled or couplable to an external power input unit 20, in particular an external human power input unit. The first element 100 comprises a first magnet 110, the second element 200 comprises a second magnet 210. The first element 100 and the first magnet 110 are both jointly rotatable about a z-axis. The second element 200 and the second magnet 210 are both jointly rotatable about the z-axis. The sensor unit 1 comprises sensor system configured to determine an angular position of the first magnet 110 about the z-axis and an angular position of the second magnet 210 about the z-axis. Furthermore, the sensor unit 1 comprises an elastic connection unit 400 configured to rotationally couple the first element 100 to the second element 200 about the z-axis such, that an angular offset between the angular positions of the first and second element 100, 200 is related to an applied torque between the first and second element 100, 200.