A man shows his biking tricks during the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

 A man shows his biking tricks during the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

A man shows his biking tricks during the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

A bike fan chooses biking helments during the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

A bike fan visits the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)

A bike fan visits the 2013 Bike Expo New York in New York City, the United States, May 3, 2013. (Xinhua/Wang Lei)