Originally Posted by
RubeRad
Look it up (or think about it), with the front disc brake mounted on the back of the fork, the act of braking causes the axle to want to pop out of the QR. Disc braking also causes your QR to rotate/loosen; my wife had it happen regularly on her mtb. You should re-snug your front QR on a disc-brake bike every ride.
Sounds like user error. I have over 2,000 miles on my 60+ pound steel e-bike commuter/utility bike, with mechanical 160mm Avid BB7 disc brakes, and the QR skewer and lever have never moved a millimeter. Not even on steep hills with 100 pounds of kid + tag-a-long bike behind me.