Hi - A friend bought a Radmini this spring and has a problem with it slowing down going down hill - The brakes are not dragging - It will not coast above 25 mph no matter what he does - He called Radpower bikes and got very little help - He was told to take a video of it happening - They suggested to him the possibility that the bearings in the motor may need to loosen up - Has anyone else experienced this or does anyone have any ideas on what could be causing this? - Thanks in advance