I once saw a guy wearing a full-face motorcycle helmet on a bicycle. He was also wearing a suit coat, slacks, tie and dress shoes. The best part is, he was riding no-handed down a fairly busy, two-lane, black-top road flapping his arms like a bird flapping it's wings. He did this from the time I spotted him until he was out of sight. Very odd! True story!

I think a full-face motorcycle helmet would be extremely hot and uncomfortable on anything but a really short ride. They do make full-face bicycle helmets that some of the downhillers and free-riders use.