You've finally been convinced by your own curiosity and wise instincts to give mountain biking a try. Well done. Whether you're coming from the road side of things or not, having a dirt-specific helmet is helpful, as it'll give you more protection along the back of your head where you're more likely to get whacked by a tree branch or rock. If function ranks highest on your list, check out the Giro Cartelle MIPS Helmet. It meets the same safety standards as higher priced helmets, sacrificing slightly on weight to meet a more friendly price point. In addition to a solid, lightweight In-Mold shell, the Cartelle also comes with the added protection of MIPS. MIPS, or Multi Directional Impact Protection System, refers to a thin basket added to the helmet's interior, which rotates slightly upon impact to absorb some of the dangerous rotational energy generated in certain crashes. It's not fail-safe, but it's a lot better than helmets of five years ago were. Understanding that trail riding includes a whole lot of climbing, Giro carved 14 vents into the Cartelle, making sure you'll have consistent airflow while you sweat. Spin the dial of the Roc Loc 5 fit system to hone in on the exact fit you want with one hand, and enjoy a plush, breathable ride with Coolmax padding along the helmet's interior.