How thin are the pads and how worn are the rotors? Could it be the backing plate on the pad rubbing the ridge on the outside edge of the rotor? Or maybe you just wore through the pad.
If you go metal-to-metal, be sure to clean the wheels as often as possible because the iron particles will stick to the wheel and start to rust.
If you go metal-to-metal, be sure to clean the wheels as often as possible because the iron particles will stick to the wheel and start to rust.