Specialized Propero 4 Bicycle Helmet (2026)Meet the all new Propero 4 helmetit brings the aero advantages of the S Works Evade 3 together with the ventilation of S Works Prevail 3, all with the comfort and confidence Specialized helmets are famous for. Every detail of the Propero 4 was created with our equation for speed in mind. Aerodynamics + Ventilation + Lightweight = Fast. AERODYNAMICS: With extensive testing in CFD and in our Win Tunnel, aerodynamics were at the forefront of the Propero