If you like your cycling tech landmarks, it was 2011 when the first aero road helmet appeared, and even that was a clip-on shell on Mark Cavendish’s regular lid as the Manx Missile sprinted to victory at the World Road Race Championships.
The idea soon caught on and manufacturers began developing dedicated aero helmets for regular raceday use, rather than specialist options purely for time trialling. The trouble with the early aero lids, though, was the improved aerodynamics almost always came at the expense of ventilation, comfort and weight.
Kask first tried to solve those issues with the introduction of the Infinity, with a sliding top panel which retracted to expose a row of vents, giving the rider an option for more ventilation when the need for cooling outweighed need to go fast. But it was still a fairly specialist helmet, and that’s where the Protone comes in, it’s a semi-aero lid which fills the gap between the Infinity and the Mojito, Kask’s lightweight, fully-ventilated climbing helmet.