Why do typical bicycle helmets lack hard shells?
carl...@comcast.net
motorcycle helmets worn by moped riders.
Cheers,
Carl Fogel
mike
carl...@comcast.net says...
> You know, like the batting helmets worn in Little League and the
> motorcycle helmets worn by moped riders.
>
than a cycle helmet and would be particularly uncomfortable when leaning
forwards in a crouch (if you cycle that way).
Mike
carl...@comcast.net
Dear Mike,
Typical bike helmet:
http://www.aegishelmets.com.tw/index.php/main/productinfo/56
Hard shell helmet from the same company:
http://www.aegishelmets.com.tw/index.php/main/productinfo/67
Both have the same certification: CE EN1078/CPSC 16CFR1303
They weigh 240 to 370 grams, 8.5 to 13.0 ounces.
Putting ventilation holes of the same size in the hard shell would
probably eliminate much the 4.5 ounce weight difference, if 4.5 ounces
makes someone particularly uncomfortable.
Cheers,
Carl Fogel
Dan O
Mine has one.
Dan O
> In article <qnatr59b4534kuun1aurrhce09unppo...@4ax.com>,
> carlfo...@comcast.net says...> You know, like the batting helmets worn in Little League and the
> > motorcycle helmets worn by moped riders.
>
> Probably for practicality. A motorcycle helmet is significantly heavier
> than a cycle helmet and would be particularly uncomfortable when leaning
> forwards in a crouch (if you cycle that way).
>
> Mike
When I raced motorcycles, I once had a helmet custom made (they
actually fitted my head and then fabricated it shell and all). I
believe they actually added weight to parts of the helmet to optimize
neutral balance on the head.
I think that helmet *would* be uncomfortable for bicycling, but my
hard shell Vetta bicycle helmet is not especially so. (Of course,
comfort is a relative thing, eh? ;-)
Owen
There is a real problem with ventilated polystyrene helmet when riding
through bush/brush in that branches can penetrate, not only through
the air vents, but the polystyrene.
I am surprised that someone hasn't come up with a helmet built in two
polystyrene sections separated by a kelvar lining to reduce
penetration.
When colliding with a branch, there's a 100% chance of being knocked
off the bike which militates against severe head injuries, but I can
attest that it is not a pleasant experience.
Owen
Tim McNamara
mike <m....@irl.cri.replacethiswithnz> wrote:
A motorcycle helmet weighs as much as 4 or 5 bicycle helmets at the
light end of the spectrum and can weigh as much as 10 bicycle helmets.
<http://www.webbikeworld.com/motorcycle-helmets/motorcycle-helmet-weights
.htm>
Bell makes a DH helmet which weighs over 2 lbs and is basically a
motorcycle helmet. What Mike says is correct- riding along in the road
or MTB position wearing that much weight on your head would rapidly
become intolerable. My neck becomes painful after 2 hours with a
standard cycling helmet weighing about 200 g (I have some bad discs in
my neck so this may be a factor) and after 4 hours the pain is really
quite intolerable.
Ventilation is also an issue. While standard bicycle helmets do not
cause an increase in body temperature while riding (contrary to early
complaints about them) they do prevent evaporation and result in sweat
running in one's eyes and soaking one's hair. This would be much, much
worse in a motorcycle style helmet.
carl...@comcast.net
Dear Tim,
carl...@comcast.net
wrote:
Dear Owen,
How does something hitting your helmet hard enough to knock you off
your bicycle and onto the ground militate against severe head
injuries?
Cheers,
Carl Fogel
SMS
> Ventilation is also an issue. While standard bicycle helmets do not
> cause an increase in body temperature while riding (contrary to early
> complaints about them) they do prevent evaporation and result in sweat
> running in one's eyes and soaking one's hair. This would be much, much
> worse in a motorcycle style helmet.
The early bicycle helmets had hard shells, _and_ ventilation. It's more
of the evolution of helmets where they went from being based on helmet
designs from other activities, to being tailored specifically for
cyclists. Since all of the impact absorbing properties of the helmet are
in the foam, there is really no reason to have the weight of a hard shell.
It's like car bumpers which dropped the metal outer covering in favor of
a lighter plastic cover over the impact absorbing foam.
This is covered on the Bicycle Helmet Myths and Facts web site at:
"http://sites.google.com/site/bicyclehelmetmythsandfacts/". It's
debunked 27 myths so far.
Kinky Cowboy
Because they don't need them to just pass the certification tests.
The test assumes a cyclist will stop after the first impact, so
maintaining integrity during multiple impacts and resisting abrasion,
things which are nice to have when coming off a motorbike at 100mph,
are not really called for.
Cycle helmets are destroyed by impact; surely batting helmets use a
different impact diffusion process to provide reusability?
Kinky Cowboy*
*Batteries not included
May contain traces of nuts
Your milage may vary
carl...@comcast.net
wrote:
Dear Kinky,
So a hard shell is just to stop things from flying apart under
multiple impacts?
Why do equestrian helmets use hard shells?
http://www.aegishelmets.com.tw/index.php/main/productlist/3
"Knock-proof" appears in most of the equestrian helmet descriptions on
that page, possibly suggesting hooves in a horse-race. A bicyclist
hitting a mirror, bumper, curb, and so on presumably gets a knock.
Hmmm . . . now I'm wondering about mandatory helmet laws and riding
horses.
Cheers,
Carl Fogel
carl...@comcast.net
wrote:
Dear Steven,
Have motorcycle helmets dropped the hard shell?
Cheers,
Carl Fogel
devel...@osoftollc.com
> On Fri, 09 Apr 2010 18:53:52 +0100, Kinky Cowboy <u...@domain.com>
This is from Wikipedia so take from it what you will:
"The purpose of the hard outer shell is:
1. to prevent penetration of the helmet by a pointed object that
might otherwise puncture the skull, and
2. to provide structure to the inner liner so it does not
disintegrate upon abrasive contact with pavement. This is important
because the foams used have very little resistance to penetration and
abrasion." -http://en.wikipedia.org/wiki/Motorcycle_helmet
Equestrian helmets probably have them for the reasons you suggest. In
racing, though, those horses move faster than your average cyclist.
-Tony
(PeteCresswell)
>You know, like the batting helmets worn in Little League and the
>motorcycle helmets worn by moped riders.
Could it be anything to do with mitigating the effect of
point-loading?
Seems like a hard shell would transfer all the energy from that
load to the inner lining of the helmet - and then, if the inner
lining doesn't absorb it, to the brain.
OTOH, without the hard shell, some of that energy would be
absorbed crunching through the helmet - hopefully short of one's
head - I'm thinking of something like the edge of a cement curb
or a babyhead in a rock garden.
--
PeteCresswell
bjw
> On Fri, 09 Apr 2010 09:55:56 -0500, Tim McNamara
>
>
>
> <tim...@bitstream.net> wrote:
> > mike <m....@irl.cri.replacethiswithnz> wrote:
>
> >> In article <qnatr59b4534kuun1aurrhce09unppo...@4ax.com>,
> >> carlfo...@comcast.net says...
That's a BMX bike helmet, not a motorcycle helmet.
BMX helmets with hard shells are available in almost
every bicycle shop in this great and free country.
Helmets are designed for an intended use and to meet
a certification, not necessarily in that order. A cycling
roadie, a BMX trick rider, and a motorcyclist have different
frequency of falling-off and speeds at which they are
likely to fall off. So it's not necessarily a good idea or even
practically useful for them all to wear hats of similar
construction.
Ben
carl...@comcast.net
wrote:
Dear Ben,
Only the typical bicycle helmet lacks the hard shell--why?
That is, what makes a hard shell a bad idea or impractical or not
useful?
Cheers,
Carl Fogel
carl...@comcast.net
Dear Tony,
How does the bicycle helmet know that it need not worry about the
penetration or disintegration that apparently apply to other helmets?
Racing horses, of course, are hardly average horses.
Just coasting, I hit 51.8 mph Tuesday at the bottom of the hill on my
daily ride, due to a nice tailwind. My average top speed this year is
over 38 mph.
Are there bicycle helmets with speed ratings? Is there any warning not
to go too fast?
Cheers,
Carl Fogel
carl...@comcast.net
wrote:
Dear Pete,
If so, do motorcycle helmets less protection?
Cheers,
Carl Fogel
carl...@comcast.net
^provide
AMuzi
>> Hmmm . . . now I'm wondering about mandatory helmet laws and riding
>> horses.
* Still Just Me * wrote:
> Well, a bicycle never threw its rider because of a bad attitude.
Attorney, holding bent bicycle fork, "Ladies and gentlemen
of the jury, this defective fork suddenly sprung and threw
my client against the bus..."
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
carl...@comcast.net
<noEmai...@stillnodomainey.com> wrote:
>On Fri, 09 Apr 2010 18:43:43 -0600, carl...@comcast.net wrote:
>
>>Dear Tony,
>>
>>How does the bicycle helmet know that it need not worry about the
>>penetration or disintegration that apparently apply to other helmets?
>
>Disintegration of the foam absorption layer is limited by the plastic
>shell of a bicycle helmet. Your argument in that direction would only
>be valid if bicycle helmets were constructed only from styrofoam. So,
>it's a question of the strength of the layer, not its presence.
>
>Also, the level of hazard of bicycle vs. motorcycle is somewhat
>different, as noted by others. However, the strength of the helmet
>does not reflect on its validity, it reflects on human decision about
>helmet requirements.
>
>Ever worked with a professional slicer, the kind they use at the local
>deli? It's an incredibly dangerous tool. You could slice off a finger
>in a heartbeat (and people have done it). If it was a wood-working
>tool, it would not be sold without a variety of guards that prevent
>serious injury from that spinning blade (in fact with woodworking
>tools, you often can barely use them with the convoluted safety
>attachments they require). Yet, since it's a "butcher's tool", you can
>buy it with no safety mechanisms at all.
>
>Sometimes accepted designs and safety requirements have no sensible
>relationship.
Dear SJM,
If the micro-plastic skin on a typical bicycle helmet is sufficient to
limit disintegration, why do motorcycle, batting, equestrian, and
other helmets have hard shells strong enough to sit on?
Does anyone know of test data or standards for the disintegration
resistance on bicycle helmets?
The micro-shell on this fairly typical ~12 ounce bike helmet is about
0.016" thick and covers only half or less of the styrofoam:
http://i39.tinypic.com/2nripdt.jpg
http://i39.tinypic.com/343l0kw.jpg
Cheers,
Carl Fogel
bjw
> On Fri, 9 Apr 2010 15:23:51 -0700 (PDT), bjw <bjwei...@gmail.com>
This is a question of both personal preference and empirical
evaluation that cannot be settled by debate on Usenet.
Since BMX helmets are widely available and not expensive,
the most expeditious route to answer your question is to
obtain a BMX lid, wear it while riding for a while, see whether
it has disadvantages, and report back.
As a kid, I used to wear a Bell Biker helmet when commuting.
I have since retired it.
Ben
Simon Lewis
That seems almost ridiculously obvious. Surely you can work it out????
>
> Does anyone know of test data or standards for the disintegration
> resistance on bicycle helmets?
>
> The micro-shell on this fairly typical ~12 ounce bike helmet is about
> 0.016" thick and covers only half or less of the styrofoam:
> http://i39.tinypic.com/2nripdt.jpg
> http://i39.tinypic.com/343l0kw.jpg
>
> Cheers,
>
> Carl Fogel
More than enough to protect your thick skill should you be nudged off,
slide off or fall off your bike and it strike a wall at typical
commuting speeds.
Sure it wont protect it from a car wheel rolling over it but there you
go.
Ben C
[...]
> If the micro-plastic skin on a typical bicycle helmet is sufficient to
> limit disintegration, why do motorcycle, batting, equestrian, and
> other helmets have hard shells strong enough to sit on?
You can sit on a typical bicycle helmet without it disintegrating. It's
not very comfortable though.
The actual question you're asking is interesting and I don't know the
answer, but maybe it's just fashion. Early bike helmets did have harder
shells and were also more dome-shaped. Maybe it's harder to make those
Klingon-head patterns most helmets have these days out of hard plastic.
Frank Krygowski
>
> The micro-shell on this fairly typical ~12 ounce bike helmet is about
> 0.016" thick and covers only half or less of the styrofoam:
> http://i39.tinypic.com/2nripdt.jpg
There's a chance that micro-shell has another function. They seem to
be made of plastic that turns brittle in the sun. Then, if dropped
even gently onto pavement, the micro-shell cracks and looks unsightly,
as with your example.
Of course, the owner is then motivated to buy a new helmet, either
because he's ashamed of losing the helmet's once stylish looks, or
because he (or those who nag him) believe the magic has now leaked
out.
Furthermore, if such damage happens in a fall from a bike, rather than
from just dropping the helmet, it can generate yet another "Saved my
life!!!" story.
I believe helmet companies would use a thin layer of glass for a
shell, if they could get away with it.
- Frank Krygowski
Tim McNamara
Ben C <spam...@spam.eggs> wrote:
You have just cast helmet aesthetics in a whole new light.
FWIW, the BHSI appears to believe that cheaper, rounder, smoother
helmets provide better protection than the expensive Klingon ones.
carl...@comcast.net
Dear Ben,
Manufacturers have recommended replacing styrofoam bicycle helmets if
they're merely dropped.
So I suspect that sitting on such helmets destroys them from the
manufacturers' point of view.
Cheers,
Carl Fogel
carl...@comcast.net
wrote:
>On Apr 9, 8:35 pm, carlfo...@comcast.net wrote:
Dear Ben,
The most expeditious route to answering the question would have been
for someone who claimed that something made a hard shell a bad idea or
impractical to explain what he meant.
Cheers,
Carl Fogel
carl...@comcast.net
Dear Frank,
Does micro-shell plastic turn brittle in the sun?
I've heard that, unlike a hard shell, it does crack fairly easily if
dropped on pavement or hit by twigs and small branches off-road.
But I don't _know_ of any actual testing of how fragile micro-shell
helmets are, new or aged.
I was tempted to rewrite that sentence, but it's better to leave
"fragile" as an example of possible bias.
I think that most posters assume that the typical bike helmet is
fragile because they've seen damaged micro-shells like the one in the
picture.
I also think that any helmet manufacturer would recommend replacing
the helmet:
http://i39.tinypic.com/11ilbuf.jpg
I marked most of the small cracks in red. As far as I can tell, the
black styrofoam is uncracked and undented beyond the kind of surface
scratches that a casual thumbnail leaves in the material.
Cheers,
Carl Fogel
(PeteCresswell)
>If so, do motorcycle helmets less protection?
Dunno - but intuitively, I think I'd rather slap the side of my
melon on the edge of a concrete curb wearing a bike helmet than,
say, one of those old "full coverage" Bell motorcycle helmets -
one of which I happen to have in a closet somewhere.
Also, the motorcycle helmet seems to me tb much too heavy for
bike use. On a 3-hour ride, my neck gets sore just from a bike
helmet - and the motorcycle helmet must weigh several times as
much.
--
PeteCresswell
Dan O
> Per carlfo...@comcast.net:
And your head must weigh many times more than that.
Jay Beattie
Have you gone on a 3 hour ride without your helmet? You might find
that your neck is sore from simply holding up your head (helmeted or
not), which is not uncommon when increasing mileage or intensity, or
even due to changed position on your bike.-- Jay Beattie.
Tim McNamara
<77acdff3-2856-40ef...@r27g2000yqn.googlegroups.com>,
Jay Beattie <jbea...@lindsayhart.com> wrote:
While there is truth to that, I find that a helmet makes a big
difference to my neck. Fortunately you may make your choice about
wearing a helmet and I may make mine.
Jay Beattie
>
I can't even tell I am wearing my helmet on a descent, when it is
really scooping air. I don't know if you can say that 8oz makes a
difference until you do the same ride without a helmet. Age,position
and any number of things can account for a sore neck. I'm princess-
and-the-pea about some things, so I'm not ruling out helmet weight as
a problem for some people. But a bunch of olde tymers complaining
about neck pain is common fare at the rest home, where no one wears
helmets. -- Jay Beattie.
Tim McNamara
<49c2d570-7a48-463e...@z7g2000yqb.googlegroups.com>,
Jay Beattie <jbea...@lindsayhart.com> wrote:
> On Apr 10, 6:21 pm, Tim McNamara <tim...@bitstream.net> wrote:
> > In article
> > <77acdff3-2856-40ef-9379-f420c9f44...@r27g2000yqn.googlegroups.com>,
> > Jay Beattie <jbeat...@lindsayhart.com> wrote:
> >
> > > On Apr 10, 5:12 pm, "(PeteCresswell)" <x...@y.Invalid> wrote:
> > > > Per carlfo...@comcast.net:
> >
> > > > >If so, do motorcycle helmets less protection?
> >
> > > > Dunno - but intuitively, I think I'd rather slap the side of my
> > > > melon on the edge of a concrete curb wearing a bike helmet
> > > > than, say, one of those old "full coverage" Bell motorcycle
> > > > helmets - one of which I happen to have in a closet somewhere.
> >
> > > > Also, the motorcycle helmet seems to me tb much too heavy for
> > > > bike use. On a 3-hour ride, my neck gets sore just from a bike
> > > > helmet - and the motorcycle helmet must weigh several times as
> > > > much.
> >
> > > Have you gone on a 3 hour ride without your helmet? You might
> > > find that your neck is sore from simply holding up your head
> > > (helmeted or not), which is not uncommon when increasing mileage
> > > or intensity, or even due to changed position on your bike
> >
> > While there is truth to that, I find that a helmet makes a big
> > difference to my neck. Fortunately you may make your choice about
> > wearing a helmet and I may make mine.
>
> I can't even tell I am wearing my helmet on a descent, when it is
> really scooping air. I don't know if you can say that 8oz makes a
> difference until you do the same ride without a helmet. Age,position
> and any number of things can account for a sore neck. I'm princess-
> and-the-pea about some things, so I'm not ruling out helmet weight as
> a problem for some people. But a bunch of olde tymers complaining
> about neck pain is common fare at the rest home, where no one wears
> helmets.
In my case I attribute the sensitivity to helmet weight to a couple of
bad discs in my neck (quite possibly the same reason the old timers
gripe about their necks. Since I'm 50 I am approaching old timerhood
myself). I've ridden 300 km and 600 km brevets with a lot of discomfort
and 500 km of PBP with no helmet and no neck discomfort.
I get problems with sweat running into my eyes when wearing a helmet
that don't happen when I don't, but overall the helmet doesn't make me
feel hotter.
bjw
> On Fri, 9 Apr 2010 23:53:49 -0700 (PDT), bjw <bjwei...@gmail.com>
I'm not that interested in answering the question. That doesn't
benefit anyone, it merely propagates my possibly groundless
opinion. I'm interested in increasing the sum total of
human knowledge by promoting empirical testing and
learning from experience. (Part of my job is experimental
design, so if you like, I'm designing an experiment by which
RBT readers can learn if hardshell helmets have any
significant disadvantages for their uses.) As previously
noted, I have performed this experiment myself, albeit
with an older generation of foamhat.
Anyway, I didn't say hard shells were a bad idea. I said
"not necessarily a good idea or even practically useful for
them all to wear hats of similar construction." A minor
difference. An idea that is neutral or basically insignificant
(other than perhaps providing reassurance to RBT worriers)
is not necess. a good idea, but doesn't rise to the level
of bad idea.
Ben
Lou Holtman
Ben, Ben Ben. You know Carl. He asks a question and ask more questions
after each possible explaination posted by others just for the sake of
it. If you want to stop it just say 'I don't know and I don't care'.
That is not very polite so you don't bother at all so he has to buy a
hard shell hockey helmet and and find out himself. He will be looking
like a dork and gets very warm in the summer heat.
Lou
(PeteCresswell)
>Have you gone on a 3 hour ride without your helmet? You might find
>that your neck is sore from simply holding up your head (helmeted or
>not), which is not uncommon when increasing mileage or intensity, or
>even due to changed position on your bike.-- Jay Beattie.
It's been awhile - bc over the winter I finally came around to
wearing my helmet all the time instead of just MTB riding... but
one of the reason's I was not wearing it was the neck issue -
less neck soreness without.
Maybe I'll re-visit it today or tomorrow on my 3-hour loop.
--
PeteCresswell
Dan O
It occurs to me that added wind resistance from the helmet may be more
of problem than weight, and would tax muscles and neck structures in a
less natural way.
carl...@comcast.net
wrote:
>I'm not that interested in answering the question.
Dear Ben,
Yes, that was apparent.
Cheers,
Carl Fogel
carl...@comcast.net
wrote:
Dear Pete,
Why would a hard-shell motorcycle helmet offer less protection than a
typical bicycle helmet?
That is, what's intuitive about removing the hard shell that covers
the same styrofoam?
In any case, hard shell _bicycle_ helmets are much lighter than
_motorcycle_ helmets.
Typical bike helmet:
http://www.aegishelmets.com.tw/index.php/main/productinfo/56
Hard shell helmet from the same company:
http://www.aegishelmets.com.tw/index.php/main/productinfo/67
Both have the same certification: CE EN1078/CPSC 16CFR1303
They weigh 240 to 370 grams, 8.5 to 13.0 ounces.
Putting ventilation holes of the same size in the hard shell would
probably eliminate much the 4.5 ounce weight difference, if 4.5 ounces
makes someone particularly uncomfortable.
For a little historical perspective, shipping weights for hard shell
bike helmets were down to 24 ounces ("SW 1 1/2 lbs") in 1981:
http://bulgier.net/pics/bike/Catalogs/bikecology-81/bike11.jpg
I'm still just wondering why typical bicycle helmets lack the hard
shell practically every other helmet uses.
Cheers,
Carl Fogel
Jay Beattie
>
> - Show quoted text -
The most I've done in a day is 204 miles, the Seattle to Portland --
one year with a Bell V1 Pro boat-anchor helmet, but I was young and
beautiful (as Jobst would say), and it didn't cause me a sore neck.
That kind of mileage and intensity (I rode it fast with a bunch of
racers on a lark) now would cause me sore everything. My current
helmet is so light, that I bet the effect (if any) would be a sore
neck sooner rather than later. But that wouldn't matter, because my
back would be killing me, and the hardware in my ankles would be
poking through the skin, and my arms would be tired, etc., etc.
Growing old sucks. Note to older riders -- premedicate! It really
helps. -- Jay Beattie.
carl...@comcast.net
Dear Jay,
For what it's worth, the Bell V1 seems to have been about 500 grams,
1.1 lbs, ~18 ounces:
"In 1985 the Bell V1 Pro was cutting edge at 500 grams. Now helmets
weight is less than 250 grams."
http://smithersmpls.com/2005/06/
(I wonder how accurate that 500 gram comment is?)
For fun, I weighed what's on my head on a ride.
42 grams glasses
70 grams skull cap, wet and wrung out
339 grams helmet
-----
451 grams, ~1 lb, ~16 ounces
Helmet tests typically use a ~5 kg/ ~11 lb "head".
Cheers,
Carl Fogel
Jay Beattie
> On Sun, 11 Apr 2010 11:15:41 -0700 (PDT), Jay Beattie
>
>
>
>
>
But the Bell V1 Pro was not cutting edge -- it was just an upgrade of
the Biker trying to break in to the ranks of the foam-only helmets.
My regular helmet was a Giro foam only helmet with a lycra stocking
cover. The coach on my racing team thought that any big rider should
have a hard shell helmet, thus I was prescribed the V1 salad bowl.
Then Giro and others came out with the thin shell helmets. The V1 was
certainly an improvement over the Bell Biker, but heavier that the
first generation Giros, etc.-- Jay Beattie.
(PeteCresswell)
>Growing old sucks.
... but beats hell out of the alternative.
--
PeteCresswell
(PeteCresswell)
>Why would a hard-shell motorcycle helmet offer less protection than a
>typical bicycle helmet?
This is strictly intuition - I'm no engineer.
But my take is that one of the important things a helmet does is
absorb energy that would otherwise be absorbed by the brain.
Seems to me like a hard helmet could transfer energy instead of
absorbing it.
Helmet hits edge of curb.
Helmet goes "crunch"... energy has been absorbed by helmet.
Helmet goes "bonk"... energy has been transmitted through the
outer shell of the helmet.
Like I said: I'm no engineer... this is strictly intuitive
speculation.
--
PeteCresswell
mike
carl...@comcast.net says...
> On Fri, 9 Apr 2010 17:02:18 +1200, mike
> <m....@irl.cri.replacethiswithnz> wrote:
>
> >In article <qnatr59b4534kuun1...@4ax.com>,
> >carl...@comcast.net says...
> >> You know, like the batting helmets worn in Little League and the
> >> motorcycle helmets worn by moped riders.
> >>
> >Probably for practicality. A motorcycle helmet is significantly heavier
> >than a cycle helmet and would be particularly uncomfortable when leaning
> >forwards in a crouch (if you cycle that way).
> >
>
> Dear Mike,
>
> Typical bike helmet:
> http://www.aegishelmets.com.tw/index.php/main/productinfo/56
>
> Hard shell helmet from the same company:
> http://www.aegishelmets.com.tw/index.php/main/productinfo/67
>
> Both have the same certification: CE EN1078/CPSC 16CFR1303
>
> They weigh 240 to 370 grams, 8.5 to 13.0 ounces.
>
> Putting ventilation holes of the same size in the hard shell would
> probably eliminate much the 4.5 ounce weight difference, if 4.5 ounces
> makes someone particularly uncomfortable.
>
reasons:
Firstly - style. Most road-cyclists (it seems) would rather be seen
wearing something that might look at home in Darth Vader's wardrobe than
in a pus-coloured pudding bowl.
Secondly - speed. It is _obvious_ from the shape of the white helmet
that you can cycle much faster in it.
Thirdly - safety. If you leave the road (accidentally) and end up in a
canal or some other body of water, the white helmet will buoy you up
better.
Fourthly - safety again (seriously this time). If they both have the
same certification (and I assume that it is a safety-based
certification), it would not seem to make much difference.
Fifthly - comfort. I have worn something that looks very similar to the
pudding-bowl when kayaking and rafting. In my experience it was always
much less comfortable than any of my cycle helmets have been - and
wobbled.
And, finally - well...never mind, that should be enough for now.
Mike
mike
carl...@comcast.net says...
> On Fri, 09 Apr 2010 10:39:59 -0700, SMS <scharf...@geemail.com>
> wrote:
>
> >On 09/04/10 7:55 AM, Tim McNamara wrote:
> >
> >> Ventilation is also an issue. While standard bicycle helmets do not
> >> cause an increase in body temperature while riding (contrary to early
> >> complaints about them) they do prevent evaporation and result in sweat
> >> running in one's eyes and soaking one's hair. This would be much, much
> >> worse in a motorcycle style helmet.
> >
> >of the evolution of helmets where they went from being based on helmet
> >designs from other activities, to being tailored specifically for
> >cyclists. Since all of the impact absorbing properties of the helmet are
> >in the foam, there is really no reason to have the weight of a hard shell.
> >
> >It's like car bumpers which dropped the metal outer covering in favor of
> >a lighter plastic cover over the impact absorbing foam.
> >
> >This is covered on the Bicycle Helmet Myths and Facts web site at:
> >"http://sites.google.com/site/bicyclehelmetmythsandfacts/". It's
> >debunked 27 myths so far.
>
> Dear Steven,
>
> Have motorcycle helmets dropped the hard shell?
>
As Stephen didn't answer that one I will.
No.
Why do you ask?
(PeteCresswell)
>Also, the motorcycle helmet seems to me tb much too heavy for
>bike use. On a 3-hour ride, my neck gets sore just from a bike
>helmet - and the motorcycle helmet must weigh several times as
>much.
Relative weights I get, using helmets at had:
Bell "Magnum" MC helmet: 1480 grams
Giro "Zean" bike helmet: 350 grams
-----------------------------------
Diff: 1130 grams = 2.5#
Put another way, the bike helmet weighs in at .77 pounds, while
the MC helmet weigs in at 3.3 pounds.
--
PeteCresswell
bjw
>
> Typical bike helmet:
> http://www.aegishelmets.com.tw/index.php/main/productinfo/56
>
> Hard shell helmet from the same company:
> http://www.aegishelmets.com.tw/index.php/main/productinfo/67
>
> Both have the same certification: CE EN1078/CPSC 16CFR1303
>
> They weigh 240 to 370 grams, 8.5 to 13.0 ounces.
>
> Putting ventilation holes of the same size in the hard shell would
> probably eliminate much the 4.5 ounce weight difference, if 4.5 ounces
> makes someone particularly uncomfortable.
You keep saying that, but I doubt you can get 4.5 ounces
by cutting holes out of the hard shell. The whole hard shell
probably weighs no more than 6 oz or so. The volume
of material in the holes, assuming 15 holes about 1cm x 5cm
area and the shell is 3 mm thick (probably an overestimate),
is 22.5 cm^3 and plastics are typically 0.9-1.2 g/cm^3, so
that's at most 1 oz of material in the holes.
If you want to try it, there's probably an old BMX helmet
somewhere in a thrift store near you that you could sacrifice.
(Whether 4.5 ounces matters is a question of the reader's
preferences.)
Ben
bjw
Carl practices the Socratic method of inquiry. That means
he asks you questions until either he gets the answer he
wants, you get irritated and lose your cool, or both.
Fortunately, nobody on RBT knows where to get any
hemlock-flavored energy drink.
I read RBT not primarily for information or unalloyed pleasure
(haha, he said "alloy"), but also a source of irritainment.
RBT has provided years of practice for my
lack-of-communication skills, and I feel a debt to it
that I must repay by irritaining Carl.
Ben
Frank Krygowski
<noEmailto...@stillnodomainey.com> wrote:
> However,
> it's difficult to get many riders to wear helmets at all...
Depends on your definition of "difficult," I guess. Some
jurisdictions have adopted the following strategy:
1) Enthusiastically portray all bicycling as extremely dangerous, and
as a major source of serious or even fatal head injury.
2) Portray certified-for-minor-bump helmets as necessary lifesavers.
Frequently state that they prevent 85% of either ill-defined "head
injuries," or brain trauma, or fatalities. Any of those will work;
nobody's going to read the source "research" anyway.
3) Pass laws making it illegal to ride a bike without a helmet.
4) Strictly enforce those laws, to the point of jailing or arresting
(even tasing) repeat offenders.
5) Be sure there's almost no public exposure to objections to the
laws, or to the supposed "science" behind them. If such exposure does
occur, be sure the objections are ridiculed instead of answered.
Enlist some online helpers, if possible.
Those steps have worked well in Australia and New Zealand. To be
perfectly accurate, they've worked better at suppressing cycling than
at getting people to don helmets. But so what? If helmet wearing
reaches 90%, even if there are fewer cyclists and no reduction in
serious head injuries per remaining cyclist, a helmet promoter can
pretend the campaign's a success.
- Frank Krygowski
carl...@comcast.net
<m....@irl.cri.replacethiswithnz> wrote:
Dear Mike,
Skipping down to safety, your fourth point, if two helmets pass a
standard test, it only means that they both passed the test, not that
they were the same.
On an A-B-C-D-F scale, the D and A grades are passing, but hardly
equal.
The original helmet standards were pitifully low, and they have been
lowered over the years.
In any case, even if both kinds of helmets are equal, my question is
_why_ the typical bicycle helmet is different from what practically
everyone else uses--motorcyclists, moped riders, equestrians, skaters,
kayakers, little league, hockey, lacrosse, sky jumpers, rock climbers,
and so on.
As for comfort, why does a hard shell wobble when you kayak, as
opposed to a microshell bike helmet?
Cheers,
Carl Fogel
carl...@comcast.net
Dear Mike,
Have motorcycle, lacrosse, hockey, kayak, baseball, rock climbing, or
equestrian helmets dropped the hard shell?
That is, why do typical bicycle helmets lack hard shells, as opposed
to practically every other kind of helmet?
Cheers,
Carl Fogel
carl...@comcast.net
<noEmai...@stillnodomainey.com> wrote:
>On Fri, 09 Apr 2010 22:50:41 -0600, carl...@comcast.net wrote:
>
>>>Sometimes accepted designs and safety requirements have no sensible
>>>relationship.
>>
>>Dear SJM,
>>
>>If the micro-plastic skin on a typical bicycle helmet is sufficient to
>>limit disintegration, why do motorcycle, batting, equestrian, and
>>other helmets have hard shells strong enough to sit on?
>
>See my previous post and the last line I re-quoted above. Helmet
>design is often non-sensicle, tradition based, and subject to the
>likes and dislikes of riders (Consider that in some states more fond
>of Darwinism, motorcyclists are not required to wear helmets).
[snip]
Dear SJM,
Since you mention tradition, let me put the question in evolutionary
terms.
I'm wondering _why_ the original hard-shell of the early styrofoam
bicycle helmet was lost, but was retained by practically every other
kind of helmet--motorycycle, baseball, lacrosse, hockey, rock
climbing, kayaking, equestrian, and so on.
If the likes and dislikes of bicycle riders led to the loss of the
hard shell, what made bicycle riders dislike it so much?
Cheers,
Carl Fogel
Michael Press
<06450e0b-e6b5-434c...@u21g2000yqc.googlegroups.com>,
bjw <bjwe...@gmail.com> wrote:
That works until Carl puts the thrill seeker in Carl's kill file.
--
Michael Press
carl...@comcast.net
wrote:
Dear Pete,
Yes, motorcycle helmets whose shells extend well below the rider's
ears weigh more than bicycle helmets.
But I'm wondering why the original hard shell disappeared from the
bicycle helmet, and yet remains on practically every other kind of
helmet.
Weight doesn't seem to explain things, at least not as a practical
matter.
Typical bike helmet:
http://www.aegishelmets.com.tw/index.php/main/productinfo/56
Hard-shell helmet from the same company:
http://www.aegishelmets.com.tw/index.php/main/productinfo/67
Both have the same certification: CE EN1078/CPSC 16CFR1303
They weigh 240 to 370 grams, 8.5 to 13.0 ounces.
Put another way, the 350 gram hard-shell helmet from that company
weighs only about 20 grams more than your Giro 350 gram example--and
that's without any ventilation holes in the shell or styrofoam.
Cheers,
Carl Fogel
SMS
> Carl practices the Socratic method of inquiry. That means
> he asks you questions until either he gets the answer he
> wants, you get irritated and lose your cool, or both.
Or you get tired of his whole shtick and filter him out completely.
Dan O
wrote:
> Frank Krygowski <frkry...@gmail.com> considered Sun, 11 Apr 2010
> 18:24:55 -0700 (PDT) the perfect time to write:
>
> >On Apr 11, 8:58 pm, * Still Just Me *
> ><noEmailto...@stillnodomainey.com> wrote:
> >> However,
> >> it's difficult to get many riders to wear helmets at all...
>
> >Depends on your definition of "difficult," I guess. Some
> >jurisdictions have adopted the following strategy:
>
> >1) Enthusiastically portray all bicycling as extremely dangerous, and
> >as a major source of serious or even fatal head injury.
>
> >2) Portray certified-for-minor-bump helmets as necessary lifesavers.
> >Frequently state that they prevent 85% of either ill-defined "head
> >injuries," or brain trauma, or fatalities. Any of those will work;
> >nobody's going to read the source "research" anyway.
>
> ridicule anyone who reads the science, while misquoting it themselves.
>
> Then the one where they get schools, group ride organisers and anyone
> in the media to mandate helmets.
> And if people won't accept them, stop them riding instead (see the UK
> Post Office).
>
>
>
> >3) Pass laws making it illegal to ride a bike without a helmet.
>
> >4) Strictly enforce those laws, to the point of jailing or arresting
> >(even tasing) repeat offenders.
>
> in NZ.
Now I'm not exactly sure what this references, but yeah - (and with
all due respect to Australian and New Zealand citizens) there's some
weird stuff going on down there. And I notice the the anti-helmet
folks seem to reference Australia and New Zealand a *lot*. It might
as well be Mars to me, though.
>
> >5) Be sure there's almost no public exposure to objections to the
> >laws, or to the supposed "science" behind them. If such exposure does
> >occur, be sure the objections are ridiculed instead of answered.
> >Enlist some online helpers, if possible.
>
> >Those steps have worked well in Australia and New Zealand. To be
> >perfectly accurate, they've worked better at suppressing cycling than
> >at getting people to don helmets. But so what? If helmet wearing
> >reaches 90%, even if there are fewer cyclists and no reduction in
> >serious head injuries per remaining cyclist, a helmet promoter can
> >pretend the campaign's a success.
>
> Until someone points out that the elephant in the room is The
> Netherlands.
Absolutely.
carl...@comcast.net
wrote:
Dear Pete,
Maybe there's a misunderstanding?
A hard-shell is just a covering, not the whole helmet.
Both kinds of helmets have a styrofoam interior.
But a typical bike helmet replaces the hard outer shell of a normal
helmet with a ~0.016" plastic cover called a microshell, which covers
about half the styrofoam, while adding a dozen or more holes for
ventilation.
The typical hard shell covers the same styrofoam with far fewer (or
even no) ventilation holes.
If anything, a hard shell will spread an impact over a greater portion
of the styrofoam.
With a hard shell, the "crunch" zone absorbing the same impact will be
broader and shallower. As a crude analogy, think of a swan dive and a
belly flop--as long as the diver doesn't hit the bottom, the pool of
water absorbs the same energy.
A motorcycle helmet has a thicker and stronger shell than the kind of
hard shell bicycle helmets worn by some BMX riders (or equestrian,
kayaking, lacrosse, hockey, skating, etc. helmets)
The thinner hard shells of those helmets are in turn still much
thicker and stronger than the typical bicycle helmet, whose microshell
covers about half the styrofoam and a dozen or more vents.
I'm wondering why the hard shell was lost in bicycle helmets and what
that means. The original styrofoam bike helmets that replaced the
leather hairnet helmets around 1980 had hard shells.
For contrast, a construction worker's "hard hat" helmet is just a hard
shell supported by a webbing with no styrofoam interior. It's intended
primarily to spread the impact of small debris falling from the floors
above--when a bolt falls thirty feet and bounces off the hard shell,
the impact is spread over the whole head and neck through the webbing
instead of the bolt going through the skull.
Cheers,
Carl Fogel
carl...@comcast.net
wrote:
>On Apr 11, 9:31 pm, Phil W Lee <phil(at)lee-family(dot)me(dot)uk>
>> >4) Strictly enforce those laws, to the point of jailing or arresting
>> >(even tasing) repeat offenders.
>>
>> You forgot ramming them off their bicycles with a car, as has happened
>> in NZ.
>
>Now I'm not exactly sure what this references, but yeah - (and with
>all due respect to Australian and New Zealand citizens) there's some
>weird stuff going on down there. And I notice the the anti-helmet
>folks seem to reference Australia and New Zealand a *lot*. It might
>as well be Mars to me, though.
Dear Dan,
This may be what Phil has in mind:
http://groups.google.com/group/rec.bicycles.misc/msg/0295a4f4399eeed9
The New Zealand story:
http://www.stuff.co.nz/nelson-mail/news/2944321/Officers-force-excessive-cyclist
Canada is closer than the South Pacific or Mars:
8/20/09 05:48:07 PM
V1 Pro Helmets get tickets in Vancouver
This is a heads-up (punny) to Vancouver BC riders still using the
venerable Bell V1 Pro helmets. This is the one that looks like leather
straps done in plastic. The police here are going to ticket for a
non-legal helmet; apparently they are too old. I just got a warning
but the nice lady cop said my name would be on a list and if they
caught me again it would be $109 ticket. So I got a new helmet for
$65.
Also, they were already warning and ticketing for straps not done up.
I guess the law says the helmet must be "properly fitted" Also giving
warnings for tipped back not protecting the forehead helmets.
http://www.roadbikerider.com/407.htm?sessid=jhcfnmdib
Cheers,
Carl Fogel
(PeteCresswell)
>But a typical bike helmet replaces the hard outer shell of a normal
>helmet with a ~0.016" plastic cover called a microshell, which covers
>about half the styrofoam, while adding a dozen or more holes for
>ventilation.
>
>The typical hard shell covers the same styrofoam with far fewer (or
>even no) ventilation holes.
>
>If anything, a hard shell will spread an impact over a greater portion
>of the styrofoam.
>
>With a hard shell, the "crunch" zone absorbing the same impact will be
>broader and shallower. As a crude analogy, think of a swan dive and a
>belly flop--as long as the diver doesn't hit the bottom, the pool of
>water absorbs the same energy.
>
>A motorcycle helmet has a thicker and stronger shell than the kind of
>hard shell bicycle helmets worn by some BMX riders (or equestrian,
>kayaking, lacrosse, hockey, skating, etc. helmets)
This is an excellent example of why somebody who knows nothing -
like me - should keep their mouth shut.... -)
--
PeteCresswell
Tim McNamara
Phil W Lee <phil(at)lee-family(dot)me(dot)uk> wrote:
> Frank Krygowski <frkr...@gmail.com> considered Sun, 11 Apr 2010
> 18:24:55 -0700 (PDT) the perfect time to write:
>
> >Those steps have worked well in Australia and New Zealand. To be
> >perfectly accurate, they've worked better at suppressing cycling
> >than at getting people to don helmets. But so what? If helmet
> >wearing reaches 90%, even if there are fewer cyclists and no
> >reduction in serious head injuries per remaining cyclist, a helmet
> >promoter can pretend the campaign's a success.
> >
> Until someone points out that the elephant in the room is The
> Netherlands.
And Copenhagen. While cycling there has increased dramatically- and
helmets are the exception rather than the rule- there are fewer cycling
related deaths. 37% of commuting to school and work is done by bicycle
in Copenhagen and 70%+ of cyclists ride year-round despite the long
Danish winter (which is generally mild in terms of temperature).
The Danish government has earmarked $36 million per year over five years
to promote cycling through infrastructure, support services, ad
campaigns, etc. The driving motivator for Danes to cycle to their
destinations appears to be convenience far above any other factor (e.g.,
cost, environmental concerns, etc.). Compare that to most US cities
where there is little or no effort to make cycling a convenient
transportation option- and where there may even be efforts to
deliberately make the infrastructure hostile to cycling (e.g., St. Louis
Park MN where there are signs telling walkers and cyclists that,
contrary to state law, they have no rights of way and must yield to
cars. They've done this by designating specific crosswalks on the
primary cycling commuter route as non-crosswalks).
Anyway, the clear upshot (contrary to Steven's insistence) is that
helmets do not make for safe cycling.
Frank Krygowski
> I notice the the anti-helmet
> folks seem to reference Australia and New Zealand a *lot*. It might
> as well be Mars to me, though.
Helmet skeptics reference Austrlia and New Zealand a lot because those
countries passed all-ages mandatory helmet laws in the early 1990s,
and they strongly enforced them.
By doing so, they produced the best data on what happens when such
laws are passed, and what happens when almost all (remaining)
bicyclists suddenly put on helmets. It's like a big experiment, where
we get to see the real results of what helmet promoters often say -
"If only bicyclists would wear helmets, up to 85% of head injuries
would be prevented, and up to umpteen billion dollars medical expenses
would be saved."
Except that in those countries where it was actually tried, it failed
completely. Cycling dropped tremendously, head injuries per remaining
rider actually rose, and the citizens spent more on helmets than was
ever saved in medical expenses. And that's before taking into account
the rising obesity, which reduced cycling probably contributed to, at
least a bit.
BTW, we have friends who have biked in Australia and others who biked
in New Zealand. Another couple, good friends of ours, are currently
bike touring in NZ. While there are certainly some differences from
American society, the differences are reportedly not that great. It's
a long way from Mars.
- Frank Krygowski
SMS
> In article<p485s5pga9js3avuo...@4ax.com>,
> Phil W Lee<phil(at)lee-family(dot)me(dot)uk> wrote:
>
>> Frank Krygowski<frkr...@gmail.com> considered Sun, 11 Apr 2010
>> 18:24:55 -0700 (PDT) the perfect time to write:
>>
>>> Those steps have worked well in Australia and New Zealand. To be
>>> perfectly accurate, they've worked better at suppressing cycling
>>> than at getting people to don helmets. But so what? If helmet
>>> wearing reaches 90%, even if there are fewer cyclists and no
>>> reduction in serious head injuries per remaining cyclist, a helmet
>>> promoter can pretend the campaign's a success.
>>>
>> Until someone points out that the elephant in the room is The
>> Netherlands.
>
> And Copenhagen. While cycling there has increased dramatically- and
> helmets are the exception rather than the rule- there are fewer cycling
> related deaths. 37% of commuting to school and work is done by bicycle
> in Copenhagen and 70%+ of cyclists ride year-round despite the long
> Danish winter (which is generally mild in terms of temperature).
<snip>
Thank you for helping to disprove the myth of "the Netherlands," if
anyone other than Phil actually still believed it! It's the eighth one
on "http://sites.google.com/site/bicyclehelmetmythsandfacts/" and the
eleventh one on "http://www.bhsi.org/negativs.htm". Also check out
"http://translate.google.com/translate?hl=en&sl=nl&tl=en&u=http%3A%2F%2Fwww.veiligheid.nl%2F",
and "http://194.255.1.161/document/che/23denweb.pdf". Sorry to let the
facts interfere with your fantasy!
The bottom line is if the U.S., U.K., etc., had the cycling
infrastructure of the Netherlands and Denmark, then you'd see none of
these campaigns to get adults to wear helmets (though you still might
see campaigns for children, as you see in the Netherlands and Denmark).
But you have to understand that there is no political will to transform
the model of the Netherlands to the U.S.. Instead the focus is on
mitigating the consequences of a poor cycling infrastructure. Not
wearing a helmet is not going to change reality.
carl...@comcast.net
wrote:
Dear Pete,
Nah, it's a good example of how to learn things--keep it up.
In "Locksley Hall," Tennyson baffled his adoring readers with the
mysterious line "Let the great world spin for ever down the ringing
grooves of change."
Someone finally asked Tennyson what on earth he meant by "ringing
grooves of change."
The poet laureate, who had ridden on the earliest railways in the
1830s, explained that he had mistakenly thought that railroad wheels
ran down grooves instead of between the rails.
Cheers,
Carl Fogel
Ben C
[...]
> I read RBT not primarily for information or unalloyed pleasure
> (haha, he said "alloy"), but also a source of irritainment.
That's a great word, and sums up RBT very well.
Michael Press
<dae01662-3eda-4fbb...@q23g2000yqd.googlegroups.com>,
Dan O <danov...@gmail.com> wrote:
> Now I'm not exactly sure what this references, but yeah - (and with
> all due respect to Australian and New Zealand citizens) there's some
> weird stuff going on down there. And I notice the the anti-helmet
> folks seem to reference Australia and New Zealand a *lot*. It might
> as well be Mars to me, though.
What do you intend to convey with "anti-helmet folks"?
--
Michael Press
Tim McNamara
SMS <scharf...@geemail.com> wrote:
Your ability to twist things to support your agenda is highly
entertaining, Steven. Thanks for being amusing.
Maybe you need to do a little more research. Most of the Danish cycling
infrastructure is just like the US infrastructure- sharing streets with
cars and trucks. There are some segregated lanes with curbs between
bikes and motor vehicle traffic. Most of the infrastructure is just
bike lanes (albeit larger, more prominent and better designed than in
most US cities. But we are talking a government that the American right
wing would consider utterly communist and would precipitate a new civil
war if tried here. We're close enough to that now.)
The real difference is the Danes, not the infrastructure, based on my
experience with Danes at least. They are more likely to think
cooperatively than competitively, in contrast to Americans. They are
more willing to take a step back and let someone else go first. Danes
would consider preventable traffic deaths to be a scandal (we think of
those deaths as part of the cost of "progress").
On the other hand, their taxes are higher than ours. if you buy a car
in Denmark, by the time you've paid all the taxes you've paid for two
cars. ISTR the nominal income tax rate is something like 50%. Despite
that the Danes consider themselves to be the happiest society in Europe
(2006, 2007, 2008, 2009).
Must be all that bicycling!
> The bottom line is if the U.S., U.K., etc., had the cycling
> infrastructure of the Netherlands and Denmark, then you'd see none of
> these campaigns to get adults to wear helmets (though you still might
> see campaigns for children, as you see in the Netherlands and Denmark).
>
> But you have to understand that there is no political will to transform
> the model of the Netherlands to the U.S.. Instead the focus is on
> mitigating the consequences of a poor cycling infrastructure. Not
> wearing a helmet is not going to change reality.
Nor is it likely to significantly improve your safety.
My mitigation plan for poor cycling infrastructure is (1) choose my
roads wisely and (2) know how to ride my bike with good skills. It's
worked for about 46 years of riding bikes. I don't count on anybody
else to keep me safe on the roads.