I am really not sure....
I truly appreciate and 'dig' the look of these helmets.
...found a link to some bike helmets....but have seen a cool one with a visor (kind of like a space helmet) on the BackDraft site video where the cars twist thru the hills of Europe.
Pacto Store - Vintage Racing Helmets and Oldschool Motorcicles
i really dig the helmet the guy has in this vid:
SUNDAY OF THUNDER.mp4 - YouTube