After climbing Independence Pass out of Aspen and Hoosier Pass between Alma and Breckenridge on Tuesday, the 121 surviving racers in Colorado’s weeklong USA Pro Challenge were toast. But to reach the day’s ascent total of 12,000 vertical feet (!), they still had to punch themselves in the gut and ride up the short but demoralizing Moonstone climb. This group was about five minutes back of the leaders. They made not a sound as they passed.