Ah, here's one from a pro-helmet resource: http://www.bhsi.org/limits.htm http://www.bhsi.org/limits.htm It indicates that helmets in the U.S. are only tested

Ah, here's one from a pro-helmet resource: http://www.bhsi.org/limits.htm http://www.bhsi.org/limits.htm It indicates that helmets in the U.S. are only tested for 14 mph impacts. It's not that the helmet stops working altogether, it's that the helmet's protection really isn't sufficient. It'd be better to wear a full-face motorcycle helmet, but of course that'd be miserable on a bike.