Especially for mid-drive powered ebikes it is very important to be aware about the forces on the chain when changing gears. While on a traditional mountain bike experienced riders are well aware how to reduce for a split second the load on the pedals to allow a smooth and almost noiseless change of gears, it is much more difficult with mid-drive ebikes. Riders are typically less aware about the real tension on the chain when changing gears, which can lead to a nasty cracking noise causing also a lot of stress for the cassette and chain.
To mitigate this problem it is advised to have a sensor fitted to signal the motor controller that the rider is changing gears. The controller can then reduce or turn off the motor for a short moment to take load off the chain.
We do not recommend mid-drive ebikes without these sensors as it can lead to a heavy wear and tear of the drive train, possibly causing high maintenance cost after only a few months.