Helmets

"OG" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Ian Smith" <[email hidden]> wrote in message
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Quoted message said:

OG said:

"Ian Smith" <[email hidden]> wrote in message
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>
> Commenting about teh performance of imaginary helmets, however, is
> hardly relevant to the discussion of real helmets, so the original
> comment seems reasonably fair.

I'm not really sure what you are alleging here. The study makes it
clear it
tested three different versions of bicycle helmets.
Quote

"Three types of helmets were investigated. One hard-shell helmet (type
A),
one non-shell helmet (type B) and one ribbed helmet (large ventilation
holes) with hard shell (type C). All three models are of modern design
with
chin strap attachment both at the sides and at the rear part of the
helmet."

Which bit of the study do you think is 'imaginary' ?

The existence of hard-shell cycling helmets in shops. You could buy
them 10 years ago, I haven't seen one for nearly that long.

Aha,
you are saying that the microshell helmets available now are not the same
as the hard shell helmets that were tested then.

OK, you may be right.

On the other hand the 1991 follow up to Hodgson's 1990 study showed that
microshell helmets behaved more like hard shell at lower speeds. Is there
evidence to show that they are worse at the higher speeds in the Swedish
study?

And finally, are no-shell helmets still available?

Since nobody has responded to this post in the last few days is it fair to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

In article <[email hidden]>
OG <[email hidden]> wrote:
<snip>

Quoted message said:

Since nobody has responded to this post in the last few days is it fair to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

Probably about as fair as assuming that there isn't any good scientific
evidence to show that they don't.

OG said:

Since nobody has responded to this post in the last few days is it fair to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

regards, Ian SMith
--
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"Rob Morley" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article <[email hidden]>
OG <[email hidden]> wrote:
<snip>

Quoted message said:

Since nobody has responded to this post in the last few days is it fair
to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

Probably about as fair as assuming that there isn't any good scientific
evidence to show that they don't.

If there is good scientific evidence I would be very interested in seeing
it.

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

OG said:

Since nobody has responded to this post in the last few days is it fair
to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

Funny.

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

OG said:

Since nobody has responded to this post in the last few days is it fair
to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

Funny.

What do you find funny? Basic, routine logic, or the suggestion that
you actually do something to try and find out the answer? Or is it
both?

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

OG said:

Since nobody has responded to this post in the last few days is it fair
to
assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

Quoted message said:

Funny.

Why? Anyone can do scientific experiments and if they think about
them the right way the results can be scientific evidence. You
don't need a degree, a white coat and a peer-reviewed publication
for it to be science.

If you want to find something out and can't find out if someone's
done the work for you already it's much better science to DIY than
assume it's a certain answer.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Sun, 26 Nov 2006 00:39:42 -0000, OG <[email hidden]> wrote:
> Since nobody has responded to this post in the last few days is it fair
> to
> assume that there is not any good scientific evidence that micro-shell
> helmets give rise to a 'grab and rotate' hazard?
About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

Quoted message said:

Funny.

Why? Anyone can do scientific experiments and if they think about
them the right way the results can be scientific evidence. You
don't need a degree, a white coat and a peer-reviewed publication
for it to be science.

Swift: "It is useless to attempt to reason a man out of a thing he
was never reasoned into."

Quoted message said:

If you want to find something out and can't find out if someone's
done the work for you already it's much better science to DIY than
assume it's a certain answer.

Pete.

Ian Smith wrote on 26/11/2006 14:30 +0100:

Quoted message said:

What do you find funny? Basic, routine logic, or the suggestion that
you actually do something to try and find out the answer?

OG displays definite troll like attributes. He makes an assertion and
then challenges other to disprove it without offering any evidence at
all for his assertion. And then declares his assertion is right because
no-one has offered evidence to disproved it.

What is known in the trade as a logical fallacy.

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Sun, 26 Nov 2006 00:39:42 -0000, OG <[email hidden]>
wrote:
>
> Since nobody has responded to this post in the last few days is it
> fair
> to
> assume that there is not any good scientific evidence that
> micro-shell
> helmets give rise to a 'grab and rotate' hazard?

About as fair as concluding that if you post "I am Napoleon" and
no-one bothers to argue with you on the thirty-thousandth repetition
then you must, indeed, be Napoleon.

Further, an absence of proof to the contrary does not prove the
hypothesis.

Further further, I posted my experimentation that tended to contradict
your assertion BEFORE you posted. Why not do your own
experimentation?

Funny.

What do you find funny? Basic, routine logic, or the suggestion that
you actually do something to try and find out the answer? Or is it
both?

You mean you were serious?

Are you saying you had a gauge to ensure that the force applied between head
and surface was the same for both skin and helmet passes? You didn't make
this clear in your original description . . .

"Any one can try this - find surface, kneel down, place head on surface,
lean into surface, slide head. Add helmet and repeat"

No description of ensuring the force is the same for both tests there.

And neither is there anything in your testing to support the allegation that
microshelled helmets give rise to a grab and rotate hazard which is what I
was asking for.

Hodgson's studies showed no increased risk for microshelled helmets at
10km/h, and that microshelled helmets behaved like hard shell. The Swedish
study did not claim an increased hazard for hard shell helmets at 20km/h. I
was simply asking if there was any evidence for increased rotation hazard
with the majority of helmets on sale today.

"Tony Raven" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Ian Smith wrote on 26/11/2006 14:30 +0100:

Quoted message said:

What do you find funny? Basic, routine logic, or the suggestion that you
actually do something to try and find out the answer?

OG displays definite troll like attributes. He makes an assertion and
then challenges other to disprove it without offering any evidence at all
for his assertion. And then declares his assertion is right because
no-one has offered evidence to disproved it.

No I don't
Other people have claimed that helmets give rise to a increased grab and
rotate hazard.

I have looked at a commonly quoted study and found that there is a definite
increased risk for one type of helmet (unshelled plain expanded polystrene),
but I'm not sure about what evidence there is for the majority of helmets on
sale today (microshell)

I am asking for good evidence that can support the claims of others.

On Sun, 26 Nov 2006 15:15:23 -0000, "OG" <[email hidden]>

Quoted message said:

I
was simply asking if there was any evidence for increased rotation hazard
with the majority of helmets on sale today.

Perhaps you could measure the size of a person's head, then measure
the size of a person's head + helmet, and see if the second is larger;
if so, that would be evidence that the second situation was more
likely to produce an impact (being a larger target); and hence an
increased chance of rotational injury.

in message <[email hidden]>, OG

(') said:

Since nobody has responded to this post in the last few days is it fair
to assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

As far as I know, there's no hard data on the 'grab and rotate' hazard
of /any/ cycle helmet type. There's generally not enough research on cycle
safety altogether, and I think this is just another aspect which has never
actually been studied.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; not so much a refugee from reality, more a bogus
;; asylum seeker

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

OG said:

"Ian Smith" <[email hidden]> wrote in message
news:[email hidden]...
>
> Further, an absence of proof to the contrary does not prove the
> hypothesis.
>
> Further further, I posted my experimentation that tended to contradict
> your assertion BEFORE you posted. Why not do your own
> experimentation?

Funny.

What do you find funny? Basic, routine logic, or the suggestion that
you actually do something to try and find out the answer? Or is it
both?

You mean you were serious?

Are you saying you had a gauge to ensure that the force applied
between head and surface was the same for both skin and helmet
passes? You didn't make this clear in your original description .
. .

Here's a free clue: Sometimes it is possible to tell the difference
between things without a gauge.

No, I did not use a gauge. Would you need a gauge to determine which
of two lights was red and which was blue? Would you need a a gauge to
tell you whether 99 degrees C water was hotter than 1 degree C water?

Quoted message said:

"Any one can try this - find surface, kneel down, place head on
surface, lean into surface, slide head. Add helmet and repeat"

No description of ensuring the force is the same for both tests there.

Stop whining and actually try it for yourself. You will find the
difference so marked that no gauge is necessary. The helmet grabs more
even if you put much less force on it.

Do you use a gauge to tell the difference between red traffic lights
and green traffic lights?

Quoted message said:

And neither is there anything in your testing to support the allegation that
microshelled helmets give rise to a grab and rotate hazard which is what I
was asking for.

I tested a microshell helmet.

You are posting that no testing exists to support the claim. I am
telling you (told you already) that simple testing highlights that it
is distinctly possible. If you actually had any interest you could do
the testing yourself, but it is apparent you're actually more
interested in spouting nonsense than finding the answer.

regards, Ian SMith
--
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|o o|
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<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Sun, 26 Nov 2006 15:15:23 -0000, "OG" <[email hidden]>

Quoted message said:

I
was simply asking if there was any evidence for increased rotation hazard
with the majority of helmets on sale today.

Perhaps you could measure the size of a person's head, then measure
the size of a person's head + helmet, and see if the second is larger;
if so, that would be evidence that the second situation was more
likely to produce an impact (being a larger target); and hence an
increased chance of rotational injury.

and of course, being larger, more likely to be rotated.

"burt" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Sun, 26 Nov 2006 15:15:23 -0000, "OG" <[email hidden]>

Quoted message said:

I
was simply asking if there was any evidence for increased rotation hazard
with the majority of helmets on sale today.

Perhaps you could measure the size of a person's head, then measure
the size of a person's head + helmet, and see if the second is larger;
if so, that would be evidence that the second situation was more
likely to produce an impact (being a larger target); and hence an
increased chance of rotational injury.

and of course, being larger, more likely to be rotated.

But the Swedish experiments did not find dangerous levels of rotation except
for unshelled helmets.

"Simon Brooke" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

in message <[email hidden]>, OG

(') said:

Since nobody has responded to this post in the last few days is it fair
to assume that there is not any good scientific evidence that micro-shell
helmets give rise to a 'grab and rotate' hazard?

As far as I know, there's no hard data on the 'grab and rotate' hazard
of /any/ cycle helmet type. There's generally not enough research on cycle
safety altogether, and I think this is just another aspect which has never
actually been studied.

The Swedish study does seem to show a clear and distinct hazard for
unshelled helmets at 20km/h.

Simon Brooke wrote on 26/11/2006 16:15 +0100:

Quoted message said:

As far as I know, there's no hard data on the 'grab and rotate' hazard
of /any/ cycle helmet type. There's generally not enough research on cycle
safety altogether, and I think this is just another aspect which has never
actually been studied.

Mainly because there is no requirement in bicycle helmet standards.
This is in contrast to motor bike helmets. Since the Andersson and
Hodgson research helmet shapes have changed a lot. The topic was on
the ASTM helmet committee for consideration after testers found they had
to duct tape modern helmets on to the test dummy head to stop them being
wrenched off in a test irrespective of the tightness with which the
straps were done up. The following links are from a strongly pro helmet
site:

http://www.helmets.org/astmdocs/0411dc.htm (Item 2 on Agenda)
http://www.helmets.org/hurtmemo.htm

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

Tony Raven said:

Mainly because there is no requirement in bicycle helmet standards.
This is in contrast to motor bike helmets. Since the Andersson and
Hodgson research helmet shapes have changed a lot. The topic was on
the ASTM helmet committee for consideration after testers found they had
to duct tape modern helmets on to the test dummy head to stop them being
wrenched off in a test irrespective of the tightness with which the
straps were done up.

They seemed to imply that the big danger is from the helmet twisting so as
to "rotate away and expose the head to injury, or eject the helmet
completely" rather than cause rotational injury. ISTM that having the
helmet fall off at the slightest impact would be a safety bonus. ;-)
--
Chris

OG wrote in news:[email hidden]:

Quoted message said:

but I'm not sure about what evidence there is for the majority of
helmets on sale today (microshell)

I am asking for good evidence that can support the claims of others.

Tried it, and my head rotated a *lot* more when the helmet was on. I'm not
bald thobut, so those who spent their hormones on something other than hair
may have a different result.

Speed was very low, but I presume higher speeds would not reverse the
result.