Key dates: Aug. 10, medal event Venue: Olympic Park Big story: Connor Fields (above), a 19-year-old from Las Vegas, won the U.S. trials and has surged to a No. 2 ranking. This is only the second Olympics for BMX, so Fields could become the first American to win gold in the event. Top U.S. prospects: Besides Fields, Nic Long of Lakeside, Calif., finished second to Fields at the trials and is on the team with David Herman of Denver. Others to watch: World No. 1 Sam Willoughby of Australia and defending gold medalist Maris Strombergs of Latvia should press Fields for gold. Little-known fact: BMX bikes have only one gear and one brake.