Without a doubt, the most important piece of equipment you can own for mountain biking, besides the bike itself, is a helmet. Nothing will ruin your ride – or life as you know it – faster than a head injury, so you know to take proper precautions. All commercial helmets will technically do the job, but if you spend enough time in the saddle, you’ll want something that fits well, is light and comfortable, and offers maximum protection for your riding style.