After having my rear wheel/motor stolen from my Magnum UI5, I ordered another one. After putting my new motor on (BFSWX02 36V 26 1612223580-6) I noticed that I can only go up to 19 mph on pedal assist. My old Magnum UI5 Motor went up to 22 mph on pedal assist. So far, the dealer has yet to explain why this motor seems weaker. I spent $378 for this wheel, so I think it should work as good as my old one. I would appreciate any advice or suggestions on this matter.