Being a baseball dad, i'm at the local park quite a bit. the kids are turning 13, or whatever age it is that doesn't legally require a helmet.
i see my kid's friends riding, w/o and it makes me nuts! mostly bmx, or 29ers - they aren't doing anything crazy, but it isn't about
the predictable....
then i saw a younger sister, riding with her helmet on the handlebars. cause her brother wasn't wearing his.
wanted to lose it.
more details on that title 39 helmet thing:
http://www.state.nj.us/transportation/commuter/bike/regulations.shtm