ebike Motor stuttering and jerking from time to time

[Chaser]

My ebike motor is stuttering and jerking, I'm wondering if there is any way to tell if it is the motor or the motor controller causing this problem?

 

[Edwardo]

It could be a loss of connection. I have seen an ebike bottle battery that broke internally and caused the same problem whenever the connection was lost.

 

[bray]

A faulty hall effect sensor can also cause this problem.

 

[BobW]

Check that the brake lever isn't cutting off power to the controller, or any loose connectors. When does this happen? If when you hit a bump in the road, or anything else.