Akuma Helmet - V1 Ghost Rider
Internal Shape and Fit
The V-1 seems to have a "neutral" fit; by that I mean that it should fit both long oval and round shaped heads, and, believe it or not, Rick claims that it painlessly fits that size XL light bulb between his shoulders without pain, albeit rather snugly. A neutral fit isn't as easy to accomplish as you'd think, because many of the big-name helmet manufacturers seem to get it wrong, falling on one or the other tail of the normal distribution (aka The "bell" shaped curve), rather than within the one Sigma portion of the curve.
The V-1 in large seems to run true to size; that is, it fits just about how I would expect a size large to fit. I do think the chin bar and maybe the inside of the visor are just a touch shorter than normal; there's enough room for my nose and chin but it's a tiny bit crowded and the back of the visor tends to steam up just a bit more than I'd like.
Read what WebBikeWorld has to say about the Akuma V1 HERE