Helment Damage.

zod wrote:
*Check out this pic......this could be that dude's skull

http://tinyurl.com/9jbfa *


So of course you're now going to start wearing a full-face helmet, since
it's his face shield that's cracked.


--
tholub - Kinetic Sculptor
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well the reason i noticed it 5 days after is right after the crash i
just stood up and dusted my self off, checked to make sure everything
was ok, then i got back on, rode home, and when i take my helmet off i
dont like put it in a cabnient or soemthing so i just kinda chucked it
onto the ground and didnt look at the back.


--
Evan Byrne

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"tholub" writes:

All I am saying is that it is an obvious physical fact that you're
more likely to hit your helmet than you are to hit your unprotected
head, therefore the fact that someone hit his helmet in a crash
doesn't mean that he would have hit his head.

What you wrote is: "Let's be realistic ... [hitting your helmet] is
not at all proof that you would have hit your head."

That's pretty strong wording in my book, so I assume you have an
anti-helmet prejudice. Admittedly that's an assumption on my part.
If I am wrong, just say so. Either way, it is fair to assume that I'm
not the only one who read it that way, so pro-helmet responses seem
right on target to me.

And yes, I have a pro-helmet bias. The issue came up in R.S.U a while
ago. I searched for credible evidence that helmets actually do
measurable harm in low energy impacts and, despite lots of noise from
anti-helmet folks, could not find any support for the notion. I did
find a paper by bicycle dsafety experts from a university in the UK
systematically refuting the claims.

Lastly, getting back to being "realistic". I've hit my helmet many
times and have yet to create a tear in the shell that large. Based
just on the damage to the helmet, I have to conclude that Evan was
fortunate to have been wearing it.

Ken

tholub wrote:
*So of course you're now going to start wearing a full-face helmet,
since it's his face shield that's cracked. *


I already wear one when doing DH mountain biking, you'd be stupid not
to.


--
zod - Southern Fried mUni

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damn"
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U-Turn wrote:
*Compared with the size and mass of the human body, the helmet is
indeed negligible in both terms. An engineer would have no problem
saying that if you smash your helmet, you would have smashed your
head. *


Why would one compare the size and mass of a helmet to that of the human
body? Last time I checked, most people wore helmets just on their
head.

Which engineer are you talking about? Yourself? I would have a problem
making such a statement. There are 1,001 ways to smash a helmet, and
1,001 ways to smash your head, but the two events are not 100%
correlated.

...especially since Evan's involved. Frankly, I'm a bit skeptical about
that guy's claims. Call me a critic, but I still don't believe he broke
his helmet doing a backflip down three stairs.


--
maestro8 - Mad Scientists for World Domination

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Rowan wrote:
*
A helmet which is not used damages the wallet with a low energy
impact. Helmets suck!!! Notice that no "Unicycle safety experts"
systematically refute any of the claims. Bicycles and unicycles are
completely different vehicles, hence the laws for wearing helmets on
bikes not unicycles. *


'hence' is IMO not the appropriate term there, as it states that there
are no laws for unicycle helmets -because- they are completely different
to bikes.

The real reason there are no helmet laws for unicycles is surely because
the law hasn't turned its attention towards them, due to them being
possibly the least used form of transport.


--
onewheeldave - Semi Skilled Unicyclist

"You can't outrun Death forever.
But you can make the ******* work for it."

--MAJOR KORGO KORGAR,
"Last of The Lancers"
AFC 32
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I thought I would add some more fuel to the fire on the helmet debate.
I have included a graph on impact survival experience from NASA-STD
3000. One point that you should note is that a head impact from a
standing position (no added riding velocity) is on the edge of
survivability. This assumes that the person's head is the first thing
to hit the ground and the ground did not absorb any of the impact
(concrete). Hope this helps with your debate.


+----------------------------------------------------------------+
| Attachment filename: impact.jpg |
|Download attachment: http://www.unicyclist.com/attachment/300643|
+----------------------------------------------------------------+

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jim.furfaro - Rocket Scientist

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maestro8 wrote:
*Why would one compare the size and mass of a helmet to that of the
human body? Last time I checked, most people wore helmets just on
their head.*
Because a poster above was talking about center of mass. The COM of a
person would be essentially unchanged by adding a helmet. As far as
size goes, the size of the body compared with the size of the helmet
means that the helmet is way less than 1% of the volumetric footprint of
the body. So as far as an accident goes, the size of a person is
unaffected by a helmet. Therefore, the class of accidents is unchanged
by the addition or deletion of a helmet.

*Which engineer are you talking about? Yourself? *
Yup.

*I would have a problem making such a statement. There are 1,001 ways
to smash a helmet, and 1,001 ways to smash your head, but the two
events are not 100% correlated.
*
Why do you think 100% correlation is required? If a helmet saves death
or injury in a reasonable subset of accidents (it does), then it is
worth wearing.


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U-Turn - As long as my feet keep movin'...

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Why do you think 100% correlation is required? If a helmet saves death
or injury in a reasonable subset of accidents (it does), then it is
worth wearing.



Ah, but there you get into the tricky part. You are more likely to have
a head injury in a car accident than in a bike accident (even with a
seat belt), but to suggest that people wear helmets in cars is
considered ridiculous. Similarly, pedestrians get head injuries in a
reasonable subset of accidents, but no one thinks of advocating for
helmet usage for pedestrians.

The helmet debate is much more about perception of risk than it is about
actual risk. That's not to say that helmets don't reduce risk; they do.
But the lines people draw about where helmets "should" be worn are
largely arbitrary.


--
tholub - Kinetic Sculptor
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U-Turn wrote:
*Because a poster above was talking about center of mass. The COM of
a person would be essentially unchanged by adding a helmet. (snip)
Therefore, the class of accidents is unchanged by the addition or
deletion of a helmet.*


You're failing to recognize that the dynamics of the human body are far
different than that of a rigid body. The head is not rigidly attached
to the body (or, for some, not attached at all) and is free to move with
at least three degrees of freedom, constrained by the attachment at the
neck.

Adding a helmet to the head increases its mass significantly (when you
consider _just_ the head). As the helmeted head accelerates during an
accident, the neck will be subjected to more stress and strain than
normal. One's head does not have to be impacted to get it to
accelerate, so in some cases, a helmet can cause more damage than it can
prevent.

Note I am not discouraging anyone from wearing a helmet, but I would
like to point out that it is not 100% safe. It is every rider's
personal decision to risk permanent, irreversable brain injury; wear a
helmet now or a drool bib later, your choice.


U-Turn wrote:
An engineer would have no problem saying that if you smash your
helmet, you would have smashed your head.
[/b]


-Backpedal posted by U-Turn -
*Why do you think 100% correlation is required?*


I don't... your original post was a very blatant statment, in effect:
"An engineer says if A then B." Such a statement implies 100%
correlation. Your "an engineer" qualification lends no weight to your
witless deduction, and offends other engineers / physicists / scientists
/ people of good taste.


--
maestro8 - Mad Scientists for World Domination

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