Key dates: July 29, road race; Aug. 1, time trial Venue: Road race, The Mall; time trial, start-finish at Hampton Court Palace Big story: Dutch superstar Marianne Vos, who won the prestigious Giro Donne last month less than a month after breaking her collarbone, has been winning international races since 2006, when she was 19. In Beijing she won gold medals on the track and now has chosen road racing. Top U.S. prospects: The U.S. team is lead by former Wall Street worker Evelyn Stevens, who could medal in the road race and time trial as could defending time trial gold medalist Kristin Armstrong (above), who is also recovering from a broken collarbone suffered in late May. Also a time trial medal contender is Irvine's Amber Neben, who won the world time trial gold in 2008. Others to watch: The British have a strong road racing team led by defending champion Nicole Cooke. Also Sweden's Emma Johansson is a threat both on the road and in the time trial, as is two-time defending world champion Giorgia Bronzini, who leads a strong Italian team.