Mountain bike full-face helmets have seen quite the change over the last few years. Although Fox Racing was the first to the lightweight enduro full-face game with their Proframe helmet, brands like IXS Sports, Troy Lee Designs, and 100 Percent have all joined in on the fun with their Trigger, Stage and Trajecta Helmets. Now riders have almost too many mtb helmets to pick from. So how do you know which helmet is best for you? Well, we put all 4 of these full-face helmets through a battery of tes