Fit, Protection and Style in One Helmet After years of research and development, the Troy Lee Designs Team introduced the A1 mountain bike helmet in 2013. At TLD, styling, graphics, fit, function and safety are key in everything they create. The A1 Drone is a lightweight, fully encapsulated all-mountain helmet that utilises maximum coverage and dimension to keep you safe and protected in all riding conditions. Whether you're charging single track, riding dirt jumps or grinding out miles on the XC bike, the A1 Drone helmet offers the premium fit, protection and style you want.