"Ace Freestyle Signature: An updated skateboard style helmet with larger oval vents and minor reshaping of the shell lines. It still has a round and smooth shape. For bicycle riding you must get the dual certified Ace Freestyle, not the outwardly similar Ace Skate, which is sold for skating in skate shops rather than bicycling and is not certified to the CPSC standard."
http://www.bhsi.org/skatplus.htm Use a bmx lid not snowboard etc I guess.