From what I’ve read the Airframe runs mostly true to size. A tad small but not a full size. Order your correct size unless you tend to hover in between sizes then go down a size. The Airframe has gotten excellent reviews based on everything I read, aside from the fact that it can be very noisy with the vents open due to its extremely aggressive ventilation design. But that can be solved by a pair of earplugs.
I can say this much. My size tends to hover in between large and XL with many brands. I’m at the exact point where an XL helmet feels like it fits perfectly when brand new but becomes too big after it “breaks in.” With most brand new helmets an XL fits me absolutely PERFECTLY while a large is uncomfortably tight to the point where it is difficult to breathe and my jaw gets sore. After break-in-however, the XL becomes too big and the large fits perfectly. I tried on an XL size airframe at the store and it fit me perfectly right off the shelf, which to me says it runs about average when it comes to sizing.
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