I have a Haibike treking1.0 Bosch Active line plus. 3 times the most recent the chain has come off the front sprocket and wedged between the sprocket and the motor cover. It is stuck fast the only way apparently to remove it is brute force and ignorance it is making a mess of the cover. These seem to be 0mph incidents I wonder it it is a bit of reverse peddling to find a starting position maybe coupled to a higher gear say 4th Just wondering what I can do to stop it happening.