I was riding around today and cming to a stop i rolled off the throttle and a very sudden vibration occured. you can feel i through the entire bike. it happens when i roll off the throttle. it doesnt matter what speed. it feels similar to transmission drag in a car. if you hae ever towed a load ad had to brake suddenly, the truck shakes and vibrates, kind of an anti lock brakes feel. does anyone know what this could be?