On 7 Feb 2005 19:43:36 -0800, wrote:

I agree that 10 g's is a small shock. But think about it this way.
160 lb man drops 16 feet onto his neck. He hits at about 32 feet per
second or about 20 mph. If he decelerates at 10 g's, the force is 1600
lb force. The energy is 2560 ft lbs.

You want me to believe that a helmet will protect me at higher speeds.
Now if I had to be involved in an accident at a higher speed, I would
want a helmet. I am just not sure it would be enough to be of any real
help if I went over the handlebars and hit something halfway hard head
first.

Now with a bit of luck, the man drops 16 feet and lands on his back,
and the helmet only has to adsorb the energy his head has.

Dan
Not to support helmet laws, which I don't, even smacking a helmet at
10 mph or faster can avoid major brain damage. I don't know where
exactly the cutoff point is, but I do know that a helmet striking a
truck at about 25 mph can protect the wearer from even a concussion.
Surprisingly, I didn't think I had hit my head at all. After I saw the
damage to the helmet there was no doubt. I'm sure that there are ways
to hit a helmet in such a way that the energy is concentrated to a
small area but most of the time it is spread out enough to save not
only the brain but the spine too.
ERS