Inflatable helmet, really

On Sep 10, 8:25*pm, Tom Sherman °_°
wrote:
On 9/10/2010 9:27 PM, kolldata aka AVOGADRO V wrote:



it gets only worser

Then worstest!

--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.

right ! with 5 mill invested, the fabric supplier left out some UV
then folded. moved to hawaii where his brother bought a pinapple farm.
AMF

howdya like my piece on Jones ? burned the land, killed and ate your
children...

edyeyahahahha BAU do the math. 59K here, 20K there.....got a foreign
policy idea ? nuke tests in Nevada ....

conceptually idea of spinning out spec covers for inflatable helmets
is a groove and seriously needed for the too loose cycling community.
gotta inject some seriousness here doanwanna tote up their gunbelts
afore headin' out to road warrior with donning the paperbag full
coverage inflatable.
you see honey with the ET inflatable ? sell a million in Texas.

On Sep 10, 8:00 pm, kolldata wrote:
helmet interlock ? now this sounds serious errrrrrrrrkkkkkk! now
wegotta worry about neck injury, spinal dislocations, cranial nerves
torn ass under. Frank, yawl related to Nadir ?

but seriously. by the time you get to the asphalt, usually covered
with hydrocarbons and itself a lubricious product of dead protoplasm,
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. I'd say
typically more like 6.5 than 9.

On Sep 10, 11:53*pm, Dan O wrote:
On Sep 10, 8:00 pm, kolldata wrote:

but seriously. by the time you get to the asphalt..
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. *I'd say
typically more like 6.5 than 9.

Well, the people who designed the helmet standard decided 14 mph was
the appropriate speed, equivalent to a 2 meter drop of a decapitated
head. But they decided that speed was purely perpendicular to the
surface being impacted.

Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. It's a simple vector problem.

So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. I'll let you guys take a crack at the math to find the
limiting forward speed.

- Frank Krygowski

On Sep 11, 12:36 pm, Frank Krygowski wrote:
On Sep 10, 11:53 pm, Dan O wrote:

On Sep 10, 8:00 pm, kolldata wrote:

but seriously. by the time you get to the asphalt..
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. I'd say
typically more like 6.5 than 9.

Well, the people who designed the helmet standard decided 14 mph was
the appropriate speed, equivalent to a 2 meter drop of a decapitated
head. But they decided that speed was purely perpendicular to the
surface being impacted.

Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. It's a simple vector problem.

So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. I'll let you guys take a crack at the math to find the
limiting forward speed.


Dumbass, attenuation is attenuation.

On Sep 11, 5:43*pm, Dan O wrote:
On Sep 11, 12:36 pm, Frank Krygowski wrote:



On Sep 10, 11:53 pm, Dan O wrote:

On Sep 10, 8:00 pm, kolldata wrote:

but seriously. by the time you get to the asphalt..
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. *I'd say
typically more like 6.5 than 9.

Well, the people who designed the helmet standard decided 14 mph was
the appropriate speed, equivalent to a 2 meter drop of a decapitated
head. *But they decided that speed was purely perpendicular to the
surface being impacted.

Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. *However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. *It's a simple vector problem.

So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. *I'll let you guys take a crack at the math to find the
limiting forward speed.

Dumbass, attenuation is attenuation.

Couldn't do the math, I see!

Or, maybe you were so embarrassed by the obvious result that the only
way you could pretend to save face was to use kiddie-level rudeness.

If attenuation is attenuation, then you should manufacture helmets
that are 1/8" thick. Like the egg cartons loved by some contributors
to this discussion, they'll provide _some_ attenuation. As with
official bike helmets, you can always pretend it's enough.

- Frank Krygowski

On Sep 11, 10:01 pm, Frank Krygowski wrote:
On Sep 11, 5:43 pm, Dan O wrote:



On Sep 11, 12:36 pm, Frank Krygowski wrote:

On Sep 10, 11:53 pm, Dan O wrote:

On Sep 10, 8:00 pm, kolldata wrote:

but seriously. by the time you get to the asphalt..
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. I'd say
typically more like 6.5 than 9.

Well, the people who designed the helmet standard decided 14 mph was
the appropriate speed, equivalent to a 2 meter drop of a decapitated
head. But they decided that speed was purely perpendicular to the
surface being impacted.

Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. It's a simple vector problem.

So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. I'll let you guys take a crack at the math to find the
limiting forward speed.

Dumbass, attenuation is attenuation.

Couldn't do the math, I see!

What math? I'm not designing helmets, or designing tests for them.

Go ahead, dumbass - define the problem. I will solve it for you.
Okay? (I am not so simple as you seem to think I am, eh?)


Or, maybe you were so embarrassed by the obvious result that the only
way you could pretend to save face was to use kiddie-level rudeness.


Obviously :-)

If attenuation is attenuation, then you should manufacture helmets
that are 1/8" thick. Like the egg cartons loved by some contributors
to this discussion, they'll provide _some_ attenuation. As with
official bike helmets, you can always pretend it's enough.


Never enough. Nothing from nothing is nothing.

On Sep 11, 12:36 pm, Frank Krygowski wrote:
On Sep 10, 11:53 pm, Dan O wrote:

On Sep 10, 8:00 pm, kolldata wrote:

but seriously. by the time you get to the asphalt..
how fast are you going ? do the math.

Math exercises aside, I've crashed *plenty* of times while riding
bike, and was thinking exactly the same thing myself. I'd say
typically more like 6.5 than 9.

Well, the people who designed the helmet standard decided 14 mph was
the appropriate speed, equivalent to a 2 meter drop of a decapitated
head. But they decided that speed was purely perpendicular to the
surface being impacted.

"The" helmet standard. WTF?


Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. It's a simple vector problem.

No, it's a simple, "Ow! That hurt my head" problem. (Dumbass)


So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. I'll let you guys take a crack at the math to find the
limiting forward speed.


Limit?

Frank, seriously get an accelerometer, glue it to your helmet and fall
where did you get 6 mph from ?

On Sep 12, 1:31*am, Dan O wrote:
On Sep 11, 10:01 pm, Frank Krygowski wrote:



On Sep 11, 5:43 pm, Dan O wrote:

On Sep 11, 12:36 pm, Frank Krygowski wrote:

Others here have defended that 14 mph, saying that all you need to
worry about is the perpendicular component - and pretending that
cyclists never run into cars, I suppose. *However, if the issue is
angular acceleration caused by a grazing impact between the helmet and
the ground, then the cyclist's forward speed definitely makes a
difference. *It's a simple vector problem.

So if the vector sum of your forward speed and your head's vertical
drop speed is less than 6.5 mph, that paper's findings probably apply
to you. *I'll let you guys take a crack at the math to find the
limiting forward speed.

Dumbass, attenuation is attenuation.

Couldn't do the math, I see!

What math? *I'm not designing helmets, or designing tests for them.

Go ahead, dumbass - define the problem. *I will solve it for you.

Given: that much of the data in the cited paper involved a total
impact velocity (helmet to ground) of only 6.5 mph; and given that
according to the CPSC helmet standard, an appropriate vertical
component of that impact velocity is 14 mph;
Find: the horizontal travel velocity which will limit the total impact
velocity to 6.5 mph. Or hell, to 8.5 mph (the other velocity in that
test) if you prefer.

Bonus: Explain to us whether you normally ride faster or slower than
the velocity you calculate.

- Frank Krygowski

On Sep 12, 1:12*pm, !Jones wrote:

I don't need to read a "study" to know that helmets are a effective. ...

But, I know that they work on an *individual* level... there are lots
of ideas that are fine when applied individually but don't work as
well, if at all, when generalized. *For example: if I smoked
cigarettes, I should quit; that idea is supported by solid science.
On the other hand, making cigarettes illegal would have no effect at
all, save to **** everyone off. *Using clean syringes to inject drugs
is an effective mitigation against HIV transmission... I'll bet that
even *Frank* wouldn't argue in favor of sharing hypodermic needles!
Yet, he can't cite a single study that shows making clean syringes
available (i.e. "exchange programs", etc) reduces the HIV rate.

So, having established that a helmet is effective on my individual
level, it would be a logical fallacy to extrapolate that idea to the
general population and to say, therefore, they're good for everyone
(read: mandatory).

The other side of that is: having failed to establish the efficacy of
helmets in studies of the larger population, many conclude that *I*,
personally, should not wear a helmet, which is the statistical fallacy
of "accepting the null hypothesis" (Agresti & Finlay, 1997) as opposed
to failing to reject it. *There are quite a few "poster children" for
that fallacy in this thread.

There's some very twisted logic in that post!

For a much better parallel to typical helmet promotion: Medical
science has found no anti-cancer benefit for huge doses of vitamin C,
Linus Pauling notwithstanding.
http://www.quackwatch.com/01Quackery...s/pauling.html
Are you saying that despite such data, we should still promote vitamin
C as the most important defense against cancer? Are you saying that
even if we don't, that any particular individual is justified in
believing that vitamin C will prevent or cure their cancer?

The logic generally used in medical and health science is, if tests
show something to be ineffective, don't pretend it's effective. Move
on.

I'll also add, logic also says if data shows a problem to be
minuscule, don't over overemphasize it. Granted, that one is much
more frequently violated.

Here we have a case where people seem to be pretending cycling causes
lots of serious head injuries, more than other activities, despite
data to the contrary. And they're pretending that helmets are usually
very effective in preventing those head injuries, despite data to the
contrary.

Not that you should stop wearing your helmet, if you like. Go out
bedecked in styrofoam, purple riding shorts, St. Christopher medal,
lucky socks, lucky rabbit's foot and all the rest, and ride over to
"invest" your money in a lottery ticket, if you like. Just don't try
to pretend it's logical.

- Frank Krygowski