At Loudon, New Hampshire in 1978, Boston Cycles rider Rich Schlachter was using the brakes on his TZ750D very hard – so hard that with heat being pulled out of the discs’ inner edges by the high-conductivity aluminum carriers, their outer edges were running much hotter. When inner and outer edge temperatures are very different, the heat-expanded region stretches the cooler I.D. region permanently, so when the discs cool a bit the stretched I.D. region forces the disc into a slight cone shape – enough tilt to push the brake pads back in the calipers. When the rider next goes for the front brake, the whole lever pull is used up in squeezing the disc flat again. As Kawasaki technician Kazuhito Yoshida used to say, “Bad effect.” On corner approach there’s no time for taking a second squeeze on the lever.