Probably has something to do with Snell standards forcing US helmets to be too stiff to pass euro standards. Snell helmets don't absorb impact enough to meet Euro standards, as they're built for worst case scenario.
Euro standards: G force translated to brain below XX.
Snell standard: Helmet must survive drop of XX feet to the same point twice.
I'm anti-snell myself. I feel as if they sacrifice too much of the function of the helmet, to pass an overkill test. An overkill test that tests a 1 in a million scenario impact to the head, where the rest of the body probably wouldn't survive anyway.
