Jim@EROsports wrote:
bloodyshogun wrote:
Jim, I am curious. Do you happen to have any information on size of helmet vs aero? For a lot of helmets, my head falls on the very upper range of an M (59cm) and usually I can squeeze my head into a size M, but with noticeable discomfort. So, I often go up a L in the name of comfort.
Do you happen to have any data on how much more drag that might be?
It's all about frontal area, so larger will be slower. It is on me. I, too, fall right in between on a lot of helmets, but mediums are always faster on me. How much difference is there for you? Tough to tell without testing.
Comfort is a consideration, though, as discomfort can have a negative effect on performance.
I wouldn't say this is necessarily the case. The MET Drone as Frodeno used last year has a huge frontal area but if you have a good aero position it is hitting the clean air before it hits your shoulders and tested most aero for him for years without sponsorship. As long as it doesn't increase your total frontal area in regard to the wind the larger frontal area can be faster. I would say you are desperate for seconds if you downsize a helmet based on being worried about its aerodynamics.
http://www.220triathlon.com/gear/gear-guides/tt-bike-helmets-6-of-the-best-reviewed/9031-2.html