In 2008, American Evelyn Stevens was working as an investment banker when her sister persuaded her to compete in a bike race in Central Park. The 29-year-old was quickly hooked. She moved to Boulder, Colo., to train with former Olympic gold medalist Connie Carpenter. She won a major women’s race in Belgium this April and clinched a spot in the Olympics when she won the Exergy Tour in Idaho a month later. She’s a contender in both the road race and the time trial.