Aerodynamic efficiency and thermal comfort of road racing bicycle helmets

The main ambition of using bicycle helmet is to provide protection for riders especially from head injuries. However, for world class events a helmet becomes more important for its aerodynamic efficiency and thermal comfort. Those two factors have a proportional relationship and it is challenging to gain them at a high level. The features of the bicycle helmet (area and number of vents, position and geometry shape) are playing an important role for influencing heat transfer and aerodynamic drag. In this study, four commercial road racing helmets were tested in a wind tunnel environment for both aerodynamic and thermal evaluation. The RMIT Industrial Wind Tunnel was used to measure aerodynamic drag and profiling the heat transfer characteristics for each helmet at a range of wind speeds (20-40 km/h) and three different pitch angles (0°, 45° and 90°). Each helmet was ranked based on their aerodynamic and thermal performance.