This a resend, I may have gotten caught by the new "delete the original
post" rule.
The biggest reason that motorcycle helmets are lighter and not approvable
for SA is blunt and sharp object protection. Motorcycle trauma is usually
hitting something fairly big and flat, like the ground. In cars they need
to protect against hitting smaller objects like roll bar tubing, interior
sheetmetal corners, and penetration from sharp objects. That means stiffer
and thicker shells and visors, and thicker lining. There's also an issue of
velocity. If you fall of your bike and your head hits the ground, you've
only fallen about five feet or so, and the vast majority of your velocity
is not towards the ground and doesn't really contribute to the impact that
the helmet has to absorb. In racing, the helmet has to absorb far larger
velocities as your head hits a tube after the car has hit a wall.
This I got more than several years ago from an article about how Snell
tests helmets and what they test for, but it seems reasonable to me. What I
totally agree with is the tremendous features that the motorcycle guys get
that we don't! They have had anti-fogging systems, quick change visors (no
tools, 2.5 seconds), real ventilation, for many years!
Brian
Brian Evans
Director, Canada
MCI Wholesale Internet Services
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