animal@ihlpa.UUCP (D. Starr) (08/09/86)
I. Introductory Flame Bait
I've noticed an awful lot of wasted electricity in this group
lately over helmets and their contribution to safety. The legal
and ethical debates are interesting (and I've contributed to them),
but there have been some really stupid remarks on both sides about
what helmets actually do. For instance, there have been the standard
remarks about vision, hearing loss, how a helmet can't protect you
at speeds over 13mph, and so on. I'm used to these arguments, as I
see then in the ABATE newsletter every month, as these guys keep trying
to fight the helmet rather than the law. On the other hand, the
arguments in favor of helmet laws have turned into crash-
and-burn stories ("Yeah, well when I went down at 120mph on the
Bogoso Highway the helmet saved my life! Top that!" But they never
tell us what stupid mistake they made that put them down.) or called upon
such learned authorities as Mr. Spock (has it occured to you that if the best
support you can find for your position is a line from a "B" movie,
your position might not be worth supporting?). So here are some facts,
in the hopes that the arguments will get a bit more interesting.
II. Why helmets prevent or reduce injuries (and why 13mph is fast enough)
How many of you have read the Harry Hurt study of motorcycle accidents?
I mean read it, not just heard about it. One of the interesting things
that came out of the study was an analysis of what happens to your head
when you crash. It turns out that the rider typically leaves the bike,
travels airborne for an optional distance, strikes the pavement with some
organ other than the head, and then bounces and slides to a halt, striking
the head one or more times, usually on the side or rear. This means that
the helmet must deal with the sudden deceleration that occurs when you
hit a fixed object and must stop moving--in that direction. This is where
the 13mph rule comes in. The only velocity component that acutally has
to be absorbed is your vertical velocity--falling from the normal riding
height of your head (about 5 feet). This is well under 13mph. It is
completely true that you have to kill off a much higher velocity if you
T-bone a semi or bridge abutment. It is also true that under these
circumstances you will almost certainly die, because (as ABATE is so fond
of saying) even if the helmet protects your skull, your brains will be
extruded from your nose. Fortunately, such direct impacts are rare.
The helmet must also deal with abrasion and attempted penetration by
rocks and similar pointy objects, but these are easily licked by making
the shell hard enough. The real toughie is absorbing the 13mph vertical
impact, and that's what the hard foam in there is for.
III. So what about that ten dollar head?
One article quoted the old Bell slogan, "If you have a ten dollar head,
wear a ten dollar helmet." The slogan makes great advertising, but is
factually nonsense. Hurt's study showed that even the cheapest DOT
approved helmet is for all practical purposes as safe as the most
expensive.
This doesn't mean that expensive helmets are a ripoff--there are many
good reasons, such as comfort, fit, features, and styling, for buying a
more expensive unit. But relative safety is not.
IV. A hot time in the old lid tonight
People who live in Portland Oregon never have problems with their
helmets getting uncomfortably warm. People who ride in Kansas in July
do. I saw an ad last year where they claimed that their venting
system kept temperatures down under 105--as compared to about 115 with
a conventional helmet. At sustained high temperatures, especially on
hot days where the body is also overheated, it is possible for the brain
to get too warm, and for reflexes and judgement to be adversely affected.
(score one for ABATE again). But there is a simple solution to this
problem. Most roads are equipped with such things as resturants, ice
cream shoppes, taverns, grocery stores and other places which have air
conditioning. It is thoroughly amazing just how much good a ten-minute
stop in a cold place can do when your head starts overheating. (take that
point back, I guess).
V. Put on your eyeshades, put in your ear plugs
Vision and hearing are affected by a helmet, Tommy. Several studies have
demonstrated that the inside of a helmet is much quieter than the
outside, and that outside noises are somewhat muffled. But, the background
roar caused by wind going past your ears is almost entirely absent. The
net result is that the signal-to-noise ratio inside the helmet is actually
a lot better than it is without one. On the other hand, a lot of people
are now packing hi-fi speakers into their helmets and becoming as oblivious
to traffic sounds as that guy in the Cadillac with the windows rolled up
and the stereo blaring.
As for vision, some people with exceptional peripheral vision can see the
edges of their helmet view ports. Most people can't. Even if you can,
you can see all the world by turning your head slightly--and moving your
head side-to-side while riding is considered by many to be a good way to
help fend off soreness and cramping in the shoulder muscles. Holding your
head in one position--which many bare-headed riders have to do to keep
their baseball caps or bandannas from flying off--is a good way to
assure a stiff neck when you get off.
Additionally on the vision issue, Hurt noted that over 80% of the accidents
involved a hazard that was within 45 degrees of dead ahead. So losing
a little of your peripheral vision isn't really losing much.
VI. And speaking of the neck...
Remember the hoary old "helmets break your neck" argument? I still see
people bring it up. It did happen, once. In the very early days of the
full-face helmet, when the full-face was an open-face with a chin piece,
some people struck the ground chin-first and the back of the helmet attacked
their necks. I don't know if any necks actually got broken, or just
injured. In any case, the problem was solved by cutting away some of the
back of the helmet (unfortunately exposing a vulnerable part of the back
of the head to penetration injuries) and adding a bit of padding back there.
VII. We have liftoff...
The helmet manufacturers don't like to talk about helmet lift. For years
they denied that this phenomenon, where the helmet tries to go to the moon
and take your head with it, even exists. It does. It seems to be worst
with an ill-fitting (loose) cheapie open face helmet and no windshield.
The more expensive brain buckets now have spoilers, air dams and such
to reduce the effect to a relatively inconsequential level. But the
helmet people did nothing for their credibility by claiming for several
years that it didn't happen.
VIII. So what?
So what does this all boil down to? The helmet prevents or reduces injury
in the most typical kinds of motorcycle accident. There are accidents
where it won't do you any good, but they're not common. Wearing a helmet
does not do anything that will increase your chance of having an accident
if you're reasonably competent. On the other hand, they are hot, often
uncomfortable, and can experience adverse aerodynamic effects. Therefore,
depending upon your definitions, a helmet might make motorcycle riding
not worth doing. It boils down to your definition of acceptable risk and
your judgement of how likely you are to crash.
Now let's get back to arguing the philosophical and legal issues. They
were more fun anyway.