Disc brake rotors can be susceptible to bending and warping from trail obstacles heat build up or even during transit bent rotors cause excessive drag and unpleasant noises or even bring your ride to an early conclusion the x tools disc rotor truing tool lets you correct bends in the disc rotor the shallow slot targets smaller kinks at the outer edges while the deeper slots reach down to the spokes to correct warping and deeper bends each slot is calibrated to ma