Tearing up the singletrack this spring? Wear the Bell Full-9. In addition to full-face protection and strategic ventilation, it has an air bladder beneath its padding. It's not meant to activate during a serious crash, but can be inflated by paramedics afterward. Why? It allows the helmet to be taken off without forcing a rotation of your spine, helping prevent extra damage – and even saving your life. [$400; bellhelmets.com]