Rudy Project Bike Helmet Size Chart





Model Small Small/Medium Large
Airstorm Outlet
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Boost 01
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Protera Outlet
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Protera+
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Racemaster MIPS
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Spectrum 51.1 – 54.9cm 55.8 – 58.7cm 59.6 – 61.5cm
20⅛” – 21⅝” 22″ – 23⅛” 23½” – 24¼”
Strym
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
The Wing
54.9 – 58.7cm 59.6 – 61.5cm

21⅝” – 23⅛” 23½” – 24¼”
Volantis
54.9 – 58.7cm 59.6 – 60.6cm

21⅝” – 23⅛” 23½” – 23⅞”