Head protection - the case against

[Dave Larrington]

MartinM <[email protected]> wrote:

> Dave Larrington wrote:
>
>
>> I've got a Cateye EL400 on top
>
> Isn't that the 'ckof big 5 LED one?

No, it's the small 3-LED, 3-AAA one.

>> but for nocturnal
>> silliness such as you describe, a Petzl LED head torch is preferred.
>> But then the nocturnal silliness takes place
>> inna-low-slung-three-revolving-wheels kind of way.
>
> and I bet it comes in useful given the oft observed frequent visits by
> the P*****re fairy to one or more of those wheels ;-)

(Grasps wood) Hasn't been too bad lately, though the back tyre was found
found to have deflated itself between the Denmead Submarine Invitational 200
& the Surrey Hills. Now watch the P+nct+r+ Fairy stalk me all day tomorrow
:-(

> I dare say this would
>> not go well with a martlehat, but when riding
>> inna-low-slung-three-revolving-wheels kind of way (mate), I confine
>> headgear to a grubby speed101.com baseball cap.
>
> Are they a techno outfit from Antwerp or am I thinking of Front 242?

Given the amount of high-speed riding Mr Matt "Speed101" Weaver has been
doing in past couple of years, I am beginning to suspect that he may indeed
have started a new career in stripped-down Italian Speedcore...

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
The Real Slim Shady's gone to play tennis.

 

[Matt B]

"Peter Clinch" <[email protected]> wrote in message
news:[email protected]...
> Matt B wrote:
>
>> OK, peer pressure then, not to appear foolish enough not to have rumbled
>> a troll. All was fine until the "big guns" came in throwing wild and
>> untrue allegations around - then the bandwagon has standing room only.
>
> So how many people have done that?

A handful (NPI).

> And what makes them big guns?

They are some of the most dominant posters in this group.

> My own view is that you're not a troll in the deliberate poking an anthill
> with a stick style but you have the usenet social graces of an agitated
> wasp.

Sorry I'm not more adept - I'll try harder

>> I stated my position - one could have then ignored the thread - what was
>> the attraction to reply?
>
> Because I don't think you're /trying/ to be a troll it might just filter
> through that you can actually get a lot of useful stuff here but the
> amount of useful stuff will go up if you Get A Clue about How To Win
> Friends And Influence People.

)

> You're not on /nul points/ which is why you haven't earned a very public
> mass-killfiling (as happened to the not-very-glorious "steven" not too
> long ago), but not a very long way over.
>
>> I could not let the term DeathShed go unchallenged - nothing trite or
>> technical.
>
> Fine to take issue with "deathshed", but then you went and got trite and
> technical later on, didn't you?

Attempting to halt the discriminatory fashion of stereotyping 4x4s.

> A grand case of ignoring the spirit while sticking to the letter.

The spirit is what I had issue with, the uncharitable spirit.

>> They can be treated with contempt though.
>
> That is a negative side to freedom of speech. But it's easy enough to
> work round, because if a view presented in good order is treated with
> contempt then it's the intercession that appears contemptible, not the
> original post.

Although here certain individuals seem to thrive on the practice.

>> I don't think I started any unpleasant name calling.
>
> What was that about urcfuhrers then? Forgotten that already,

That wasn't the start of it, and that wasn't aimed at a specific individual,
that was my collective noun for the group of "vociferous", arrogant, self
glorifying individuals who persist in being offensive and rude towards me,
my motives and my intellect. The term may have been tainted by the Nazis,
but the literal translation is "urc leaders".

> or just have social graces turned off lately and don't realise that
> different people have different thresholds of offense to you?

Personal attacks are a sign of weakness when they are used to counter a
point or to sabotage a thread. I try to be robust in the face of unfounded
insults and smears.

--
Matt B

 

[David Martin]

Matt B wrote:
> Attempting to halt the discriminatory fashion of stereotyping 4x4s.

A sterotype is a lack of discrimination. So sterotyping is
indiscriminate. You were arguing for more discrimination, not less.

...d

 

[Tony Raven]

Matt B wrote:
>
> I was seriously considering it until I just read your post in another branch
> of this thread WRT the Netherlands "where one in a thousand cyclists wears a
> helmet and they have the lowest cyclist head injury rate in the world",
> without expressing why you think the two facts aren't simply coincidental.
>
> I'm not now convinced it would be good value for money :-(
>

That post was a statement of known facts. You should distinguish debate
from a review of a subject - something where many people fall down.


--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham

 

[Tony Raven]

p.k. wrote:
> David Martin wrote:
>> Helen Deborah Vecht wrote:
>>> Yebbut a helmet covers only a small part of the head.
>> ..
>>> It can cause strangulation type injuries.
>> IIRC this is not just hypothesising as Helen (being a senior A&E
>> doctor) has seen such injuries first hand.
>
>
> is that correct Helen, have you seen cycling helmet strangulation injuries
> from cycling accidents?
>

Try reading the warnings that come with every Bell helmet
(http://www.bellbikehelmets.com/downloads/Bell_Bike_OwnersManual_USCAN.pdf)
and the CPSC website on cycle helmet strangulation
http://www.cpsc.gov/cpscpub/pubs/5121.html.


--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham

 

[p.k.]

Tony Raven wrote:
> p.k. wrote:
>> David Martin wrote:
>>> Helen Deborah Vecht wrote:
>>>> Yebbut a helmet covers only a small part of the head.
>>> ..
>>>> It can cause strangulation type injuries.
>>> IIRC this is not just hypothesising as Helen (being a senior A&E
>>> doctor) has seen such injuries first hand.
>>
>>
>> is that correct Helen, have you seen cycling helmet strangulation
>> injuries from cycling accidents?
>>
>
> Try reading the warnings that come with every Bell helmet
> (http://www.bellbikehelmets.com/downloads/Bell_Bike_OwnersManual_USCAN.pdf)
> and the CPSC website on cycle helmet strangulation
> http://www.cpsc.gov/cpscpub/pubs/5121.html.

I've read those before, may i suggest you try reading the question?

The references you give are to use of cycle helmets in playgrounds with
attendant strangulation risk (apperture sizes are ste to child head sizes,
wearing a helmet is an obvious hazard.0

The subject at hand is cycle helmets used for cycling. The occurence of
strangulation type injuries was called by helen as a criticism of cycling
helmets. Dave Martin stated that Helen had seen such injuries first hand.

I'm seeking clarification not on the obvious and well known playground
hazard but the posited experince of cycling related helmet strangulation
injury.

pk

 

[MartinM]

John Hearns wrote:
> On Thu, 03 Nov 2005 10:58:13 -0800, MartinM wrote:
>
> >
> > strange, I find the opposite; especially whilst trying to wear one of
> > those LED elastic strap thingies to read audax route sheets on my
> > nocturnal sillinesses. I fashioned a strange bracket to attach a 3 LED
> > headlamp to my lid for the Dun Run which no doubt raised some chuckles.
> Details please.
> Such a thing would be useful - I have a couple of LED headtorches,
> and also did the Dun Run.

we are at crossed porpoises; the item I fashioned was from one of those
3 white LED lamps that attaches to the handlebars; but using a rear
light bracket. the only things that secure the LED elastic Petzl type
things effectively are cable ties IMX

 

[Just zis Guy, you know?]

On Fri, 04 Nov 2005 08:16:42 GMT, "Pinky"
<[email protected]> said in
<[email protected]>:

> but I wear my helmet EVERY time I ride my velo.

And when you walk near traffic? The injury profiles are similar (30%
head injuries), but there are many more pedestrians hurt than
cyclists.

>I do not find it uncomfortable or unwieldy at all.

I used to say the same until I stopped wearing one. And then I
realised that actually I did find it uncomfortable and unwieldy....

>It is bright ( even garish - which helps
>to improve my visibility)

Evidence? Specifically, evidence that a bright object above the
average car roof line contributes to being seen?

>and I have also mounted to small but powerful LED
>head lights on it and still it isn't heavy! In the summer I do not find
>that I overheat (I cycled to Budapest this year -- hottest day was 35C) and
>in cooler/wetter times it has a rainproof cover -- it helps keep my head
>warm!

Amazing! It keeps you warm in the winter but not in summer! I wonder
how it achieves that? The only study I've seen shows that helmets
increase head temperature in all conditions. Perhaps you can cite
your source?

>On at least 3 occasions I have been glad to be wearing my helmet in low
>speed forced dismounts

So often stated by helmeted cyclists. I have not hit my head while
cycling in the last 20 years. I wonder if this is more anecdotal
support for the finding that helmeted cyclists are more likely to hit
their heads?

>I am not in favour of compulsion but I am in favour of wearing a helmet and
>in my long distance tours in I see an enormous number of cyclists wearing
>helmets.

I see an enormous number of cyclists not wearing them, as well, and I
don't assume that either group is evidence of anything other than the
effect or otherwise of marketing.

>There are, of course , the vast brigade of children/teenagers on bikes who
>whirl around helmetless, with no concern for pedestrians or cars. It
>actually would appear it is this very group that would benefit from headgear
>as they perform their antics on pavements and shopping areas.

Actually they would benefit from not whirling around. But as it
happens research comparing girls and boys of similar age indicates
that the helmets make no measurable difference.

>But whenever I see or meet solo or groups of "real" cyclists there seems to
>be a high proportion of them topped off with a helmet.

For what value of real? Roadies? It's part of the team replica kit.
I see a lot of tourists who don't. And an awful lot of commuters who
don't. But that is of course irrelevant: numbers wearing has
absolutely nothing to do with assessing the quality or otherwise of
the evidence.

Guy
--
http://www.chapmancentral.co.uk

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

 

[Helen Deborah Vecht]

"p.k." <[email protected]>typed


> David Martin wrote:
> > Helen Deborah Vecht wrote:
> >>
> >> Yebbut a helmet covers only a small part of the head.
> > ..
> >> It can cause strangulation type injuries.
> >
> > IIRC this is not just hypothesising as Helen (being a senior A&E
> > doctor) has seen such injuries first hand.


> is that correct Helen, have you seen cycling helmet strangulation injuries
> from cycling accidents?

> pk

No, though I have read reports.

I have seen a fractured larynx in a helmet-wearing horse-rider.

I appreciate this is not the same thing. This girl's larynx injury was
not life-threatening, but a more severe on could result in instant
death.

I know it was almost impossible to get a cycle helmet to sit on my head
in a stable fashion, despite trying numerous helmets, using various
sizing pads and having the straps *far* tighter than anyone else I knew.
Even then, I found a minimal attempt to hit the front of my helmet could
potentially garrot me. I still wore the helmet at the time; I wouldn't
now.

I have also been in a café queue on an Audax ride, when a helmeted rider
fainted due to overheating.

--
Helen D. Vecht: [email protected]
Edgware.

 

[David Martin]

p.k. wrote:
> Tony Raven wrote:
> > p.k. wrote:
> >> David Martin wrote:
> >>> Helen Deborah Vecht wrote:
> >>>> Yebbut a helmet covers only a small part of the head.
> >>> ..
> >>>> It can cause strangulation type injuries.
> >>> IIRC this is not just hypothesising as Helen (being a senior A&E
> >>> doctor) has seen such injuries first hand.
> >>
> >>
> >> is that correct Helen, have you seen cycling helmet strangulation
> >> injuries from cycling accidents?
> >>
> >
> > Try reading the warnings that come with every Bell helmet
> > (http://www.bellbikehelmets.com/downloads/Bell_Bike_OwnersManual_USCAN.pdf)
> > and the CPSC website on cycle helmet strangulation
> > http://www.cpsc.gov/cpscpub/pubs/5121.html.
>
> I've read those before, may i suggest you try reading the question?
>
> The references you give are to use of cycle helmets in playgrounds with
> attendant strangulation risk (apperture sizes are ste to child head sizes,
> wearing a helmet is an obvious hazard.0
>
> The subject at hand is cycle helmets used for cycling. The occurence of
> strangulation type injuries was called by helen as a criticism of cycling
> helmets. Dave Martin stated that Helen had seen such injuries first hand.
>
> I'm seeking clarification not on the obvious and well known playground
> hazard but the posited experince of cycling related helmet strangulation
> injury.

Before Helen hits me with her walking stick, I'll explain what ISTR.

In th dim recesses of my memory was a post from Helen outlining throat
injuries due to ill fitted helmets being dragged back on the head and
causing strangulation type injuries.

OK, found the quote:

"And you missed out damage to the larynx from a helmet strap.

Having seen & treated a horserider with a mild laryngeal injury from
her hat, I would warn cyclist
of the possibility.

If the helmet tips back on your head and crushes your throat you could
die from an obstructed airway
faster than you would die from a head injury..."

So my memory was faulty for which I apologise. However the sentiment
remains..

...d

 

[Peter Headland]

>> in cooler/wetter times it has a rainproof cover --
>> it helps keep my head warm!

> Amazing! It keeps you warm in the winter but not in summer!
> I wonder how it achieves that?

Probably due to the addition of the rainproof cover in winter, Guy.

> The only study I've seen shows that helmets
> increase head temperature in all conditions

ISTR seeing data that whowed that some helmets actually increase
cooling at higher speeds, but many of us are unlikely to benefit
(can't go that fast anyhow except downhill). They are also pretty good
insulation against the sun (not so much of an issue in the UK, but
pretty significant here in California). Being a slaphead and very prone
to sunstroke, I have to wear something anyhow, and a helmet really does
seem cooler than the traditional cotton cap in some conditions.

--
Peter Headland

 

[Just zis Guy, you know?]

On 4 Nov 2005 11:03:17 -0800, "Peter Headland" <[email protected]>
said in <[email protected]>:

>>> in cooler/wetter times it has a rainproof cover --
>>> it helps keep my head warm!
>> Amazing! It keeps you warm in the winter but not in summer!
>> I wonder how it achieves that?
>Probably due to the addition of the rainproof cover in winter, Guy.

I haven't seen much research suggesting that a single layer of nylon
makes much odds, whereas I do know that polystyrene foam is a good
thermal insulator. But YMMV.

>> The only study I've seen shows that helmets
>> increase head temperature in all conditions

>ISTR seeing data that whowed that some helmets actually increase
>cooling at higher speeds, but many of us are unlikely to benefit
>(can't go that fast anyhow except downhill).

Cite?

>They are also pretty good
>insulation against the sun (not so much of an issue in the UK, but
>pretty significant here in California).

Any hat will do...

>Being a slaphead and very prone
>to sunstroke, I have to wear something anyhow, and a helmet really does
>seem cooler than the traditional cotton cap in some conditions.

Even though you have to cover the vents to stop yourself getting an
"interesting" sunburn pattern on your balding pate? ;-)

Guy
--
http://www.chapmancentral.co.uk

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

 

[Tim Woodall]

On Fri, 4 Nov 2005 09:52:01 -0000,
Matt B <[email protected]> wrote:
> "Rich" <[email protected]> wrote in message
> news:YCwaf.58620$m%[email protected]...
>>
>> "Tony Raven" <[email protected]> wrote in message
>> news:[email protected]...
>>> Matt B wrote:
>>>>
>>>> You seem so very definite, why, I wonder, do they find it so difficult
>>>> to comprehend.
>>>
>>> Because it goes against "common sense" in just the same way they shut
>>> down the railway system after Hatfield because it was "common sense" to
>>> minimise the danger to passengers. But by the end of the first fortnight
>>> the excess road deaths from the consequent increased road traffic had
>>> exceeded the total number of deaths in Hatfield. But they still shut it
>>> down and kept it shut down because it was "common sense"
>>
>> and seat belts, they are common sense too. Except that when the seat belt
>> law was introduced, deaths to people outside the car, pedestrians and
>> cyclists rose.
>
> Do you have sources? Were the extra deaths caused by the wearing of seat
> belts, or did they coincide for another reason?
>
Something I wrote somewhere else - I've snipped the other persons text.

====
How have you eliminated the effects of evidential breath testing from
this? (introduced 1983 - same time as the seatbelt law)

1982 there were 5934 deaths
1983 there were 5445 deaths
1984 there were 5559 deaths

1982 there were 1550 deaths attributed to alcohol
1983 there were 1110 deaths attributed to alcohol
1984 there were 1170 deaths attributed to alochol

Therefore:
1982 4384 deaths non alcohol related
1983 4335 deaths non alcohol related
1984 4380 deaths non alcohol related

Drink driving.
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_021596.pdf

Crash stats
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_032078.pdf


Pedestrians Cyclists M/Bike
1982 1869 294 1090
1983 1914 323 963
1984 1868 345 967

Motorcyclists will be impacted by the breath testing laws. Making the
(possibly unjustified) assumption that the deaths attributed to alcohol
affect M/Bike the same as population in general we would have expected
to see about 700 deaths in 1983 and 1984 for motorcyclists.

I think you could easily make the case that the 1983 seatbelt law caused
about 200-250 extra deaths as compared to the imediately preceding years.

ISTR rumours that the Isles report(1981) predicted a 3% increase in
deaths if compulsory seatbelts were introduced. Given the 1982 figures
this would imply about 180 extra deaths.
====

Tim.


--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

http://tjw.hn.org/ http://www.locofungus.btinternet.co.uk/

 

[Peter Headland]

> >> Amazing! It keeps you warm in the winter but not in summer!
> >> I wonder how it achieves that?
> >
> >Probably due to the addition of the rainproof cover in winter, Guy.
>
> I haven't seen much research suggesting that a single layer of nylon
> makes much odds, whereas I do know that polystyrene foam is a good
> thermal insulator. But YMMV.

Stop digging. As any fule kno, the cover goes over the outside of the
helmet, thus keeping the air from flowing through, thus making it much
warmer inside (the trapped air inside the vents is quite a good
insulator).

> >ISTR seeing data that whowed that some helmets actually increase
> >cooling at higher speeds, but many of us are unlikely to benefit
> >(can't go that fast anyhow except downhill).
>
> Cite?

If I could find it again, I would have done so, but I don't think it's
that surprising - some designs have huge air intakes (of course, those
are probably the ones with the least protection). As I said, I think it
would be a tenous benefit at best.

> >They are also pretty good
> >insulation against the sun (not so much of an issue in the UK, but
> >pretty significant here in California).
>
> Any hat will do...

Not so - any hat that sits directly on the head doesn't do much of a
job in this regard, IME, when you have no hair to form an insulating
barrier. My head reflects about as much as a white cotton cap. :-(

> >Being a slaphead and very prone
> >to sunstroke, I have to wear something anyhow, and a helmet really does
> >seem cooler than the traditional cotton cap in some conditions.
>
> Even though you have to cover the vents to stop yourself getting an
> "interesting" sunburn pattern on your balding pate? ;-)

So long as you are not riding in a dead straight line for hours, the
light is not shining on the same spots all the time - the vents on my
helmet aren't that big, and they are somewhat labyrinthine. I find
sunblock on the shiny dome is enough to handle it (though I do end up
looking like a badger late in the summer).

--
Peter Headland

 

[David Hansen]

On Fri, 4 Nov 2005 09:52:01 -0000 someone who may be "Matt B"
<[email protected]> wrote this:-

>Do you have sources?

You need to find out about the Durbin/Harvey Report, which the road
"safety" lobby have been keen no to discuss.

As someone has already said you also need to find out about the
Isles Report, which accurately predicted what would happen and was
suppressed by the road "safety" lobby.

The road "safety" lobby have adopted the same approach with cycle
helmets, partly because of their "success" with seat belts.

>Were the extra deaths caused by the wearing of seat
>belts, or did they coincide for another reason?

The former.


--
David Hansen, Edinburgh | PGP email preferred-key number F566DA0E
I will always explain revoked keys, unless the UK government
prevents me by using the RIP Act 2000.

 

[Pinky]

"Peter Headland" <[email protected]> wrote in message
news:[email protected]...
>> >> Amazing! It keeps you warm in the winter but not in summer!
>> >> I wonder how it achieves that?
>> >
>> >Probably due to the addition of the rainproof cover in winter, Guy.
>>
>> I haven't seen much research suggesting that a single layer of nylon
>> makes much odds, whereas I do know that polystyrene foam is a good
>> thermal insulator. But YMMV.
>
> Stop digging. As any fule kno, the cover goes over the outside of the
> helmet, thus keeping the air from flowing through, thus making it much
> warmer inside (the trapped air inside the vents is quite a good
> insulator).
>
>> >ISTR seeing data that whowed that some helmets actually increase
>> >cooling at higher speeds, but many of us are unlikely to benefit
>> >(can't go that fast anyhow except downhill).
>>
>> Cite?
>
> If I could find it again, I would have done so, but I don't think it's
> that surprising - some designs have huge air intakes (of course, those
> are probably the ones with the least protection). As I said, I think it
> would be a tenous benefit at best.
>
>> >They are also pretty good
>> >insulation against the sun (not so much of an issue in the UK, but
>> >pretty significant here in California).
>>
>> Any hat will do...
>
> Not so - any hat that sits directly on the head doesn't do much of a
> job in this regard, IME, when you have no hair to form an insulating
> barrier. My head reflects about as much as a white cotton cap. :-(
>
>> >Being a slaphead and very prone
>> >to sunstroke, I have to wear something anyhow, and a helmet really does
>> >seem cooler than the traditional cotton cap in some conditions.
>>
>> Even though you have to cover the vents to stop yourself getting an
>> "interesting" sunburn pattern on your balding pate? ;-)
>
> So long as you are not riding in a dead straight line for hours, the
> light is not shining on the same spots all the time - the vents on my
> helmet aren't that big, and they are somewhat labyrinthine. I find
> sunblock on the shiny dome is enough to handle it (though I do end up
> looking like a badger late in the summer).
>
> --
> Peter Headland
>
--




Hey Peter you seem to be the only one with a rational reply. All I said in
my post is that

"I wear a helmet all the time"
"I don't find it uncomfortable"
"my perceived evidence is that a lot of cyclists wear helmets"

and in partial response to these typical trolls ---

<"So often stated by helmeted cyclists. I have not hit my head while
cycling in the last 20 years. I wonder if this is more anecdotal
support for the finding that helmeted cyclists are more likely to hit
their heads?">

It is not anecdotal at all!
One of the times I had a forced dismount I cracked the side of my head
against a raised kerb and my helmet split but my head did not! I will not go
on with the other incidents but each time I was very well aware of the
protection I received from the helmet. None of the incidents were motor
vehicle related -- I am also very aware of helmet limitations in those
circumstances. However most of the times I have been in an accident
situations it has been at fairly low speed and most often caused by
pedestrians -- so perhaps they should wear helmets as well! I certainly feel
safer on the road than on combined cyletracks/footpaths





<"Amazing! It keeps you warm in the winter but not in summer! I wonder
how it achieves that? The only study I've seen shows that helmets
increase head temperature in all conditions. Perhaps you can cite
your source?">

"and in cooler/wetter times it has a rainproof cover -- it helps keep my
head
warm!" -- from my original post!


Again -- All I have said is that I wear a helmet all the time

In the mean time I will continue to wear mine every time I swing astride my
trusty velo and if that is a vote towards compulsion then it has to be so.

As I said in my original post I am not in favour of compulsion so why not
let me hold on to my own way of doing things! As I will obviously not effect
some of your stances on this matter -- similarly you will not effect mine.

Just look at the posters who suffer from "posting diarrhoea" on this group
to assess why they post just to promote argument!

I shall not post on this subject again. The OP raise the matter purely
because he was aware of the flood of responses he would get!

I enjoy my cycling far too much to waste time on here!


Trevor A Panther
In South Yorkshire,
England, United Kingdom.
Remove PSANTISPAM to reply

 

[Tony Raven]

Pinky wrote:

> One of the times I had a forced dismount I cracked the side of my head
> against a raised kerb and my helmet split but my head did not!

The only problem Pinky is that helmets are designed to work by
compression of the EPS. If the helmet split that's a brittle fracture
which dissipates virtually no energy and is a failure of the helmet not
the helmet working. If it split it is highly likely that it happened in
the first few ms, provided no protection at all and the injuries you
suffered would have been the same without the helmet.

If you don't believe me the Head of the UK helmet testing lab has said
"If a tight radius or angular cornered surface is impacted, it could
reduce dramatically a cycle helmet’s ability to protect the wearer.
Anything that has the potential to penetrate, even if not actually
pointed, can be disastrous." which kind of describes your kerb experience.

Sorry


--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham

 

[p.k.]

Tony Raven wrote:
> Pinky wrote:
>
>> One of the times I had a forced dismount I cracked the side of my
>> head against a raised kerb and my helmet split but my head did not!
>
> The only problem Pinky is that helmets are designed to work by
> compression of the EPS. If the helmet split that's a brittle fracture
> which dissipates virtually no energy and is a failure of the helmet
> not the helmet working. If it split it is highly likely that it
> happened in the first few ms, provided no protection at all and the
> injuries you suffered would have been the same without the helmet.
>
> If you don't believe me the Head of the UK helmet testing lab has said
> "If a tight radius or angular cornered surface is impacted, it could
> reduce dramatically a cycle helmet’s ability to protect the wearer.
> Anything that has the potential to penetrate, even if not actually
> pointed, can be disastrous." which kind of describes your kerb
> experience.
> Sorry

Is that Brrian Walker you are referring to?

From the same article:

"The helmet acts like a shock absorber. As it is impacted,
the expanded polystyrene shell of the helmet dissipates the energy
over a rapidly increasing area like a cone. Movement of a helmet
about the head and breakage of the helmet shell also assist with
the reduction of some energy."

So can we please kill off the "breakage = no protection" line that is run
regularly.

pk

 

[Tony Raven]

p.k. wrote:
> Tony Raven wrote:
>> Pinky wrote:
>>
>>> One of the times I had a forced dismount I cracked the side of my
>>> head against a raised kerb and my helmet split but my head did not!
>> The only problem Pinky is that helmets are designed to work by
>> compression of the EPS. If the helmet split that's a brittle fracture
>> which dissipates virtually no energy and is a failure of the helmet
>> not the helmet working. If it split it is highly likely that it
>> happened in the first few ms, provided no protection at all and the
>> injuries you suffered would have been the same without the helmet.
>>
>> If you don't believe me the Head of the UK helmet testing lab has said
>> "If a tight radius or angular cornered surface is impacted, it could
>> reduce dramatically a cycle helmet’s ability to protect the wearer.
>> Anything that has the potential to penetrate, even if not actually
>> pointed, can be disastrous." which kind of describes your kerb
>> experience.
>> Sorry
>
> Is that Brrian Walker you are referring to?
>
> From the same article:
>
> "The helmet acts like a shock absorber. As it is impacted,
> the expanded polystyrene shell of the helmet dissipates the energy
> over a rapidly increasing area like a cone. Movement of a helmet
> about the head and breakage of the helmet shell also assist with
> the reduction of some energy."
>
> So can we please kill off the "breakage = no protection" line that is run
> regularly.
>

Or from another article:

"If a helmet splits before the liner has partially
or fully compressed - and this is often the case - then it has simply
failed. It will not have provided the designed protection and may in
fact have absorbed very little energy at all.
If a helmet splits after fully compressing, it will have reduced
initial forces to the head, but thereafter it will afford no further
protection and any residual energy will be transmitted to the brain."

--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham

 

[David Hansen]

On Sat, 5 Nov 2005 19:45:06 +0000 (UTC) someone who may be "p.k."
<[email protected]> wrote this:-

>> If you don't believe me the Head of the UK helmet testing lab has said
>> "If a tight radius or angular cornered surface is impacted, it could
>> reduce dramatically a cycle helmet’s ability to protect the wearer.
>> Anything that has the potential to penetrate, even if not actually
>> pointed, can be disastrous."

>"The helmet acts like a shock absorber. As it is impacted,
>the expanded polystyrene shell of the helmet dissipates the energy
>over a rapidly increasing area like a cone. Movement of a helmet
>about the head and breakage of the helmet shell also assist with
>the reduction of some energy."

The statement you quote doesn't help your argument, because it is no
different to the one you are responding to. The reduction of only
some energy (compared to ideal) means a dramatic reduction in
ability to protect.

>So can we please kill off the "breakage = no protection" line that is run
>regularly.

You are trying to put up a straw man. People talk correctly of
little protection. That is not the same as no protection. When you
learn to stop misrepresenting the arguments of others your own
arguments might be more believable.


--
David Hansen, Edinburgh | PGP email preferred-key number F566DA0E
I will always explain revoked keys, unless the UK government
prevents me by using the RIP Act 2000.