Originally Posted by
Terex
A little help, Meanwhile - I thought that the helmet design you're referring was intended to dissipate energy with a two-layer design which allows energy to be better absorbed in the helmet, not prevent head rotation. I admittedly only looked at the information in passing. I'd appreciate a little more info. Thanks!
Totally wrong, I'm afraid. Which is probably a sign of your having a life...
ALL modern cycling helmets are a two layer design - there is a shell and a liner. The liner is supposed to compress absorbing energy, but it won't do so if the liner fails. Which happens at very low speeds. More, conventional helmets reduce linear impact (at low speeds anyway) but do nothing - or make worse - rotation. Which is the main cause of serious brain damage.
The anti-rotation helmets are something new. See
http://www.cyclehelmets.org/1139.html and
http://www.bikeradar.com/news/articl...l-helmet-24730
Basically: your scalp slides over the skull in impact, preventing the skull from rotating and jello-ing the contents. But when you wear a conventional helmet you no longer have this protection - the helmet has to be firmly fastened to your bonce to work - and so your brain gets sloshed around. The anti rotation helmets fix this by having a sliding membrane over their outer shell.