Pivot Shuttle Clunking Noise Descending

[Hugh-Jazz]

My brother just bought a 2020 Shuttle and has clunking sound from the motor while descending and coasting. He said it seems to be the motor engaging/disengaging on it's own through chain growth/pedal kickback. Has anyone else experienced this and if so is there a remedy?

 

[Madog]

My brother just bought a 2020 Shuttle and has clunking sound from the motor while descending and coasting. He said it seems to be the motor engaging/disengaging on it's own through chain growth/pedal kickback. Has anyone else experienced this and if so is there a remedy?

I had that on mine briefly. Discovered the cassette was a little loose. Tightened it up and no problem since.