A common issue that folks run into is that when they shift when the motor is on power, the gears make a not-so-smooth transition - leading to loud bangs when the shift happens.
This gear sensor recognizes a gear shift by monitoring shifter cable movement and temporarily cuts power, leading to smoother shifts.
This gear lets your bike's derailleur cable run through it.
* Note BBSHD motors already have a connection spot for a Gear Sensor right on the motor. BBS02 DOES NOT have this extra Higo connection.
* Note this gear sensor only works on bikes with a derailleur. Does not work with IGH.