Vibrations or shimmies while braking can be the result of warped brake rotors. The vibration occurs when brake pads make contact with the uneven surface of the warped rotor. A warped brake rotor may be caused by heavy braking for extended periods of time. Friction created by brakes can generat...
If you had warped rotors the gap would move with wheel rotation... I think. Also, that is a huge warping and rotors usually don't often warp, but, they pick up pad deposits (same effect as warping but not exactly the same thing). ...