My head is between medium/large in the kask mistral. In the past I’ve been leaning towards the smaller helmet if for no other reason to save the weight on my neck over the full distance. Now I see a trend with folks going purposely large presumably for aero advantage. Any suggestions— is it likely to matter much?
With the caveat that helmet aerodynamics are highly individual, larger helmets are typically helpful for lower head positions (to help guide air around the collarbone/shoulders) while small helmets are better for higher head positions where the helmet is more up in clean air.
Big helmet likely faster
Smaller helmet likely faster
