I haven't noticed any problems with mine, in that regard. At this point, my only grumble is the lack of power. It is very similar to the performance from my 350W geared hub motor. The only place this really matters is when riding into the wind.

To try to deal with the power issue, when riding into the wind, I have a new controller and a throttle assembly. I will try the new controller first, after all, my reason for getting this motor was to eliminate the need for a throttle.