sometimes when coasting the motor will switch between feeling a signficant drag from the motor to much more "free wheeling" feel, or the other way. Gearless hub motor so it's got to be the magnets right? But the feeling is more substantial "cogging" than when controller set to "0 "- cogging. Almost like a stage of regen. Doesn't last more than a couple of seconds and I don't consider it a "problem". Anyone know whats happening inside?