casco per bici da corsa trek ballista mipsAn aerodynamic road cycling helmet, undeniably fast, yet surprisingly lightweight, cool, and comfortable. Less wind. More win. When speed is your top priority and every Watt counts, having a helmet that cuts through the air to save you seconds is essential. Ballista is Treks fastest and most aerodynamically advanced helmet. Ballista is lightweight, cool, comfortable, and equipped with a fully integrated Mips Air safety system designed to improve