Don't forget to consider the shape of your head when looking at sizes. E.g. Specialized fits if you have a narrow head, Kask fits if you have a round head. Same as with motorbike helmets.
I like the look of the Protone, but tried one on and it turns out I have a specialized head :( If it fit me at the sides, it definitely didn't fit front to back.
Don't forget to consider the shape of your head when looking at sizes. E.g. Specialized fits if you have a narrow head, Kask fits if you have a round head. Same as with motorbike helmets.