B
Bleve
Guest
EuanB wrote:
> Bleve Wrote:
> >
> > Sure, I don't believe that helmets (or seatbelts) should be compulsory,
> > but if you choose not to wear one, you're an idiot.
> >
> I disagree. It means they've come to a different conclusion than you
> have. That doesn't make them an idiot.
In my *opinion* not wearing a helmet is an idiotic act in most
modern road riding situations. This thread cites some research
that is inconclusive. My experience is such that I believe my helmet
saved me from significant injury.
> Who are you to say otherwise? Show me the data that head injuries have
> decreased per kilometer cycled as a result of compulsion and you may
> have a point. Current data points to the opposite trend.
I think it's quite easy to mislead with statistics. I'm not
convinced that helmet compulsion makes a *long-term* change in
the number of people riding, and I don't think it's possible to
prove it eiter way. There's too many other variables involved to say
for sure.
I'm not even convinced that less people are riding these days,
even with all the other factors for why they may choose to drive, that
I've already outlined. I'd be suprised if there's any good quality
research (read - not done by a crusader) that shows either way.
So, it's opinions all the way. You know mine, I know yours
'nuff
said.
> Bleve Wrote:
> >
> > Sure, I don't believe that helmets (or seatbelts) should be compulsory,
> > but if you choose not to wear one, you're an idiot.
> >
> I disagree. It means they've come to a different conclusion than you
> have. That doesn't make them an idiot.
In my *opinion* not wearing a helmet is an idiotic act in most
modern road riding situations. This thread cites some research
that is inconclusive. My experience is such that I believe my helmet
saved me from significant injury.
> Who are you to say otherwise? Show me the data that head injuries have
> decreased per kilometer cycled as a result of compulsion and you may
> have a point. Current data points to the opposite trend.
I think it's quite easy to mislead with statistics. I'm not
convinced that helmet compulsion makes a *long-term* change in
the number of people riding, and I don't think it's possible to
prove it eiter way. There's too many other variables involved to say
for sure.
I'm not even convinced that less people are riding these days,
even with all the other factors for why they may choose to drive, that
I've already outlined. I'd be suprised if there's any good quality
research (read - not done by a crusader) that shows either way.
So, it's opinions all the way. You know mine, I know yours
'nuffsaid.
B
Bleve
Guest
flyingdutch wrote:
> Euan Wrote:
> >
> >
> > Then please read http://www.cyclehelmets.org/papers/c2022.pdf
> >
>
> Pardon my sceptisism, but what a load of HAIRY BOLLOX!!!
heh, there's a paper with an axe to grind
Interestingly, it cites stats that somewhere around 30-45%
of teenagers and adults stopped riding in the two years
after helmets were made compulsory - but also states that there
was a 35-70% reduction in head injurys reported.
Now, I didn't do super well at Uni when doing maths (I got to
do a few subjects rather more than once ), but I'd find it
difficult to draw any conclusions from that (and the author admits,
not very good quality research) that didn't suggest that there
was a significant improvement.
I'm intrigued as to the use of pedestrians as a control
group, and the reduction of head injuries there that
seem to match. There's no attempt to suggest why peds
were showing up less at hospitals with serious head injuries. Did
something change in the water in 1985?
Now, Euan, read the second last paragraph. I'll save you
the effort of finding it : "helmets undoutably prevent wounds to the
head".
My take on that paper is that it's desperatly looking for
ways to show that helmets don't work, and even then,
it has to admit it in the end, where no-one will look, after
muddying up a lot of already very muddy statistics, and somehow
claiming that white, educated people have less prangs, not that
they're more likely to wear a lid. I didn't see anything in the paper
that matched if people presenting with HI's were actually
*wearing* their lids, but I may have missed that bit, if it's in
there somewhere?
It also harps on about decining numbers of riders as a safety concern.
I
say that in the long term numbers of people riding bikes has probably
not
changed significantly because of helmet law, but *may* have changed
becase now
joe average can afford two cars. Or maybe not. But you don't know
either way.
At the end of the day, that paper is all guesswork. There's way too
many variables to come up with any real evidence over the long term
either way, but
one thing's for sure, helmets do reduce impact forces on heads, and
light bicycle helmets add bugger-all weight (mine's 200-odd grams and
isn't
sticking out like a pendulum, my hair, when wet and long, probably
weighed more ...) compared to motorbike helmets which are very
heavy and may well increase the injury rate for rotational force
crashes. I reckon the tradeoff is so minor that the inconvenience
of a helmet (worrying about helmet-head? That wind will blow your
hair all over the shop anyway .... you'll still have to brush it
if it's an issue) is far outweighed by the (even if it's very slim)
reduction in the severity of some classes of head injury.
> Euan Wrote:
> >
> >
> > Then please read http://www.cyclehelmets.org/papers/c2022.pdf
> >
>
> Pardon my sceptisism, but what a load of HAIRY BOLLOX!!!
heh, there's a paper with an axe to grind
Interestingly, it cites stats that somewhere around 30-45%
of teenagers and adults stopped riding in the two years
after helmets were made compulsory - but also states that there
was a 35-70% reduction in head injurys reported.
Now, I didn't do super well at Uni when doing maths (I got to
do a few subjects rather more than once
), but I'd find itdifficult to draw any conclusions from that (and the author admits,
not very good quality research) that didn't suggest that there
was a significant improvement.
I'm intrigued as to the use of pedestrians as a control
group, and the reduction of head injuries there that
seem to match. There's no attempt to suggest why peds
were showing up less at hospitals with serious head injuries. Did
something change in the water in 1985?
Now, Euan, read the second last paragraph. I'll save you
the effort of finding it : "helmets undoutably prevent wounds to the
head".
My take on that paper is that it's desperatly looking for
ways to show that helmets don't work, and even then,
it has to admit it in the end, where no-one will look, after
muddying up a lot of already very muddy statistics, and somehow
claiming that white, educated people have less prangs, not that
they're more likely to wear a lid. I didn't see anything in the paper
that matched if people presenting with HI's were actually
*wearing* their lids, but I may have missed that bit, if it's in
there somewhere?
It also harps on about decining numbers of riders as a safety concern.
I
say that in the long term numbers of people riding bikes has probably
not
changed significantly because of helmet law, but *may* have changed
becase now
joe average can afford two cars. Or maybe not. But you don't know
either way.
At the end of the day, that paper is all guesswork. There's way too
many variables to come up with any real evidence over the long term
either way, but
one thing's for sure, helmets do reduce impact forces on heads, and
light bicycle helmets add bugger-all weight (mine's 200-odd grams and
isn't
sticking out like a pendulum, my hair, when wet and long, probably
weighed more ...) compared to motorbike helmets which are very
heavy and may well increase the injury rate for rotational force
crashes. I reckon the tradeoff is so minor that the inconvenience
of a helmet (worrying about helmet-head? That wind will blow your
hair all over the shop anyway .... you'll still have to brush it
if it's an issue) is far outweighed by the (even if it's very slim)
reduction in the severity of some classes of head injury.
B
Bleve
Guest
Euan wrote:
> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>
> Theo> Resound wrote:
> >> And, importantly, it's only recently that we've been moving at
> >> greater than running speed. Hit the ground at 20kph and you're
> >> okelydokely. Hit the ground at 40kph and you're much more likely
> >> to break something important. Not always of course, but doubling
> >> impact speed is always going to skew your results more than a
> >> touch.
>
> Theo> Err, if you fall off your bike you will hit the ground at
> Theo> approx 20km/h regardless of the speed at which you are
> Theo> travelling. This is the design spec of bike helmets. Should
> Theo> you have a horizontal velocity of 40 km/h you will still hit
> Theo> the ground at 20km/h.
>
> I don't think that's correct.
It is, and you even say why below
> When there are two or more velocities what we have a vectors. We have
> the horizontal component (40km/h) and the vertical component. The
> vector simplistically is the root of the sum of the horizontal squared
> and the vertical squared.
>
> For the cited figures that gives a velocity of 44km/h on point of
> impact.
>
> A combination of kinetic absorption and friction dissipates the
> velocity.
Indeed it does. Friction (and tumbling losses) absorbs (read - grinds
....) the horizontal component, and the padding/shell
fracture/compaction absorbs the vertical.
Get a pumpkin, put it on the end of a 2m pole. Tip it onto the ground*
from ~2m, and then push it along the ground, and see what happens to
it.
Then, put a helmet on another pumpkin and try the same experiment.
Compare the two pumpkins. Imagine the surface of the pumpkin is
your skin and the contents, your brain.
Motorbike helmets are designed to deal with two issues -
immediate concussion, for which they will protect a skull
from damage at impacts of anything up to 20km/h or so (any more
than that, and you're rooted, helmet or not), and grinding, which is
why
they have a hard, slippery shell, so they'll slide more than grind, if
possible. My bike helmet also has a low-friction shell around
it, I presume for the same reason. My motorcycle pants are
lined with kevlar for abrasion resistance (check this stuff out :
http://www.dragginjeans.com.au/productTesting/index.htm ) to
deal with the horizontal component of a meeting with the ground.
I tested them once, 60km/h. Minor bruise (vertical component was maybe
1.5m or less falling onto fat & muscle padded bone), the kevlar
did its job of taking care of the sliding. Do the vector sums
your way, and I should have smashed my hip.
One day you want to have a look at my old motorbike helmet, the one I
crashed in.
It's nicely ground away along the side. No helmet, and I reckon I'd be
having some pretty decent scarring! Does a
bicycle helmet do the same? Not as well, but it does provide some
seperation from the ground if done up properly, which I think would
help a bit.
Now, what were you saying again? Helmets don't work, that's it, I
remember now Judo training would help eh? I did jujitsu for
more than your cited month, and the pushbike crash I had was not in the
least
affected by it. There was absolutly *no* time to fall correctly. I was
clipped in to my bike and flung backwards by the impact with the other
rider I ran into, and landed on the back of my head.
The helmet worked. It broke, my head didn't. I didn't even bleed my own
blood.
Get it?
* - dry concrete or bitumen, the local park with long, wet grass is
cheating
> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>
> Theo> Resound wrote:
> >> And, importantly, it's only recently that we've been moving at
> >> greater than running speed. Hit the ground at 20kph and you're
> >> okelydokely. Hit the ground at 40kph and you're much more likely
> >> to break something important. Not always of course, but doubling
> >> impact speed is always going to skew your results more than a
> >> touch.
>
> Theo> Err, if you fall off your bike you will hit the ground at
> Theo> approx 20km/h regardless of the speed at which you are
> Theo> travelling. This is the design spec of bike helmets. Should
> Theo> you have a horizontal velocity of 40 km/h you will still hit
> Theo> the ground at 20km/h.
>
> I don't think that's correct.
It is, and you even say why below
> When there are two or more velocities what we have a vectors. We have
> the horizontal component (40km/h) and the vertical component. The
> vector simplistically is the root of the sum of the horizontal squared
> and the vertical squared.
>
> For the cited figures that gives a velocity of 44km/h on point of
> impact.
>
> A combination of kinetic absorption and friction dissipates the
> velocity.
Indeed it does. Friction (and tumbling losses) absorbs (read - grinds
....) the horizontal component, and the padding/shell
fracture/compaction absorbs the vertical.
Get a pumpkin, put it on the end of a 2m pole. Tip it onto the ground*
from ~2m, and then push it along the ground, and see what happens to
it.
Then, put a helmet on another pumpkin and try the same experiment.
Compare the two pumpkins. Imagine the surface of the pumpkin is
your skin and the contents, your brain.
Motorbike helmets are designed to deal with two issues -
immediate concussion, for which they will protect a skull
from damage at impacts of anything up to 20km/h or so (any more
than that, and you're rooted, helmet or not), and grinding, which is
why
they have a hard, slippery shell, so they'll slide more than grind, if
possible. My bike helmet also has a low-friction shell around
it, I presume for the same reason. My motorcycle pants are
lined with kevlar for abrasion resistance (check this stuff out :
http://www.dragginjeans.com.au/productTesting/index.htm ) to
deal with the horizontal component of a meeting with the ground.
I tested them once, 60km/h. Minor bruise (vertical component was maybe
1.5m or less falling onto fat & muscle padded bone), the kevlar
did its job of taking care of the sliding. Do the vector sums
your way, and I should have smashed my hip.
One day you want to have a look at my old motorbike helmet, the one I
crashed in.
It's nicely ground away along the side. No helmet, and I reckon I'd be
having some pretty decent scarring! Does a
bicycle helmet do the same? Not as well, but it does provide some
seperation from the ground if done up properly, which I think would
help a bit.
Now, what were you saying again? Helmets don't work, that's it, I
remember now
Judo training would help eh? I did jujitsu formore than your cited month, and the pushbike crash I had was not in the
least
affected by it. There was absolutly *no* time to fall correctly. I was
clipped in to my bike and flung backwards by the impact with the other
rider I ran into, and landed on the back of my head.
The helmet worked. It broke, my head didn't. I didn't even bleed my own
blood.
Get it?
* - dry concrete or bitumen, the local park with long, wet grass is
cheating
B
Bleve
Guest
dave wrote:
> Gemma_k wrote:
> > "Bleve" <[email protected]> wrote in message
> > news:[email protected]...
> >
> >>Euan wrote:
> >>
> >>>>>>>>"Bob" == Bob <[email protected]> writes:
> >>>
> >>> Bob> The only link is that mandatory wearing of helmets, at one
> >>> Bob> point in time, discouraged cyclists, reducing cyclist
> >>> Bob> numbers. I think everyone is over that by now - does it really
> >>> Bob> discourage anyone anymore?
> >>>
> >>>Absolutely. It's a hot and smelly inconvenience which is off-putting to
> >>>the fashion conscious.
> >>
> >>Stackhats went out in, oh, 1980? Modern helmets are light, well
> >>ventilated and comfortable.
> >>
> >
> > You miss the point. It doesn't matter how good a helmet is to wear, or how
> > safe you feel in one, or how many vents there are or what kind of hairstyle
> > you have. It's all about the choice of whther you WANT to wear a helmet,
> > rather than mandating that you do....
> > Gemma
> >
> >
>
> Yup
>
> And if you wanted sensible effective legislation mandating stuff for
> safety (and I dont) Then legislate for gloves, your hands always hit
> the road.
Except in extreme cases (degloving etc) hand injuries in
bike accidents are minor scrapes or abrasions (painful, but not
long-term
incapacitating), and occasional broken bones.
Broken fingers heal reasonably well (my hands still work, I've
busted a few!). That said, I very rarely ride without gloves on on
bitumen or concrete.
As always, where you draw the line is arbitary
> Gemma_k wrote:
> > "Bleve" <[email protected]> wrote in message
> > news:[email protected]...
> >
> >>Euan wrote:
> >>
> >>>>>>>>"Bob" == Bob <[email protected]> writes:
> >>>
> >>> Bob> The only link is that mandatory wearing of helmets, at one
> >>> Bob> point in time, discouraged cyclists, reducing cyclist
> >>> Bob> numbers. I think everyone is over that by now - does it really
> >>> Bob> discourage anyone anymore?
> >>>
> >>>Absolutely. It's a hot and smelly inconvenience which is off-putting to
> >>>the fashion conscious.
> >>
> >>Stackhats went out in, oh, 1980? Modern helmets are light, well
> >>ventilated and comfortable.
> >>
> >
> > You miss the point. It doesn't matter how good a helmet is to wear, or how
> > safe you feel in one, or how many vents there are or what kind of hairstyle
> > you have. It's all about the choice of whther you WANT to wear a helmet,
> > rather than mandating that you do....
> > Gemma
> >
> >
>
> Yup
>
> And if you wanted sensible effective legislation mandating stuff for
> safety (and I dont) Then legislate for gloves, your hands always hit
> the road.
Except in extreme cases (degloving etc) hand injuries in
bike accidents are minor scrapes or abrasions (painful, but not
long-term
incapacitating), and occasional broken bones.
Broken fingers heal reasonably well (my hands still work, I've
busted a few!). That said, I very rarely ride without gloves on on
bitumen or concrete.
As always, where you draw the line is arbitary
J
Bob wrote:
> "Euan" <[email protected]> wrote in message
> news:[email protected]...
> > ... Dr Dorothy Robinson's concern, instead, is bicycle safety. She has
> > just published a study in the Health Promotion Journal of Australia that
> > is likely to send shock waves through Australian cycling communities
> > with its claim that mandatory bicycle helmet laws increase rather than
> > decrease the likelihood of injuries to cyclists.
> >
> > http://melbourne.citysearch.com.au/profile?id=53571
> >
> > Personally I'd still use a helmet in winter 'cause it's a handy place to
> > put lights Summer I'd leave the lid behind and wear a sun hat.
> > --
> > Cheers | ~~ __@
> > Euan | ~~ _-\<,
> > Melbourne, Australia | ~ (*)/ (*)
>
> That article is a load of ****.
Which article are you refering to? The article in he Health Promotion
Journal of Australia is well reserched. It draws on traffic research
going back to the first formulation of Smeed's law, published in 1949
and replicates a recent study by Jacobsen (1) in 2003.
It is not publically available on the web but you can find most of
points that Dr. Robinson makes in that paper at
http://agbu.une.edu.au/~drobinso/SNrv.pdf.
(1)Jacobsen, P. L. (2003). Safety in numbers: more walkers and
bicyclists, safer walking and bicycling . Injury Prevention, 9,
205-209.
> "Euan" <[email protected]> wrote in message
> news:[email protected]...
> > ... Dr Dorothy Robinson's concern, instead, is bicycle safety. She has
> > just published a study in the Health Promotion Journal of Australia that
> > is likely to send shock waves through Australian cycling communities
> > with its claim that mandatory bicycle helmet laws increase rather than
> > decrease the likelihood of injuries to cyclists.
> >
> > http://melbourne.citysearch.com.au/profile?id=53571
> >
> > Personally I'd still use a helmet in winter 'cause it's a handy place to
> > put lights
Summer I'd leave the lid behind and wear a sun hat.> > --
> > Cheers | ~~ __@
> > Euan | ~~ _-\<,
> > Melbourne, Australia | ~ (*)/ (*)
>
> That article is a load of ****.
Which article are you refering to? The article in he Health Promotion
Journal of Australia is well reserched. It draws on traffic research
going back to the first formulation of Smeed's law, published in 1949
and replicates a recent study by Jacobsen (1) in 2003.
It is not publically available on the web but you can find most of
points that Dr. Robinson makes in that paper at
http://agbu.une.edu.au/~drobinso/SNrv.pdf.
(1)Jacobsen, P. L. (2003). Safety in numbers: more walkers and
bicyclists, safer walking and bicycling . Injury Prevention, 9,
205-209.
J
Peter Keller wrote:
> On Mon, 22 Aug 2005 20:26:55 +1000, Claes wrote:
Much clipped
>
> I think my head probably would crack. However i am not volunteering for
> the experiment!
> Helmets are certified up to a direct blow of 20kph (very simply put) Such
> a blow will not reliably crack my skull. French research seems to show
> that at direct blows of more than 23kph, the polystyrofoam shatters rather
> than squashes, thereby offering no energy absorption whatsoever! No, to
> keep myself as safe as possible in traffic, I am not going to rely on a
> h*lm*t, even if the stupid law forces me to wear one.
>
> peter
Peter, would you have a reference to that French research? It sounds
interesting.
John Kane
Kingston ON Canada
> On Mon, 22 Aug 2005 20:26:55 +1000, Claes wrote:
Much clipped
>
> I think my head probably would crack. However i am not volunteering for
> the experiment!
> Helmets are certified up to a direct blow of 20kph (very simply put) Such
> a blow will not reliably crack my skull. French research seems to show
> that at direct blows of more than 23kph, the polystyrofoam shatters rather
> than squashes, thereby offering no energy absorption whatsoever! No, to
> keep myself as safe as possible in traffic, I am not going to rely on a
> h*lm*t, even if the stupid law forces me to wear one.
>
> peter
Peter, would you have a reference to that French research? It sounds
interesting.
John Kane
Kingston ON Canada
J
alex wrote:
> Euan wrote:
> > ... Dr Dorothy Robinson's concern, instead, is bicycle safety. She has
> > just published a study in the Health Promotion Journal of Australia that
> > is likely to send shock waves through Australian cycling communities
> > with its claim that mandatory bicycle helmet laws increase rather than
> > decrease the likelihood of injuries to cyclists.
> >
> > http://melbourne.citysearch.com.au/profile?id=53571
> >
> > Personally I'd still use a helmet in winter 'cause it's a handy place to
> > put lights Summer I'd leave the lid behind and wear a sun hat.
> > --
> > Cheers | ~~ __@
> > Euan | ~~ _-\<,
> > Melbourne, Australia | ~ (*)/ (*)
>
> Maybe the annual research report was due and someone was low on
> publications
Actually a good point. But that does not subtract from the fact that
she's been publishing in internationally recognized journals on this
topic for years.
John Kane
Kingston ON Canada
> Euan wrote:
> > ... Dr Dorothy Robinson's concern, instead, is bicycle safety. She has
> > just published a study in the Health Promotion Journal of Australia that
> > is likely to send shock waves through Australian cycling communities
> > with its claim that mandatory bicycle helmet laws increase rather than
> > decrease the likelihood of injuries to cyclists.
> >
> > http://melbourne.citysearch.com.au/profile?id=53571
> >
> > Personally I'd still use a helmet in winter 'cause it's a handy place to
> > put lights
Summer I'd leave the lid behind and wear a sun hat.> > --
> > Cheers | ~~ __@
> > Euan | ~~ _-\<,
> > Melbourne, Australia | ~ (*)/ (*)
>
> Maybe the annual research report was due and someone was low on
> publications
Actually a good point. But that does not subtract from the fact that
she's been publishing in internationally recognized journals on this
topic for years.
John Kane
Kingston ON Canada
E
Euan
Guest
>>>>> "Bleve" == Bleve <[email protected]> writes:
Bleve> Euan wrote:
>> >>>>> "Resound" == Resound <[email protected]>
>> writes:
>>
>> >> Bicycle helmets absorb kinetic energy (KE). The formula for
>> KE >> is:
>> >>
>> >> KE = 1/2 * M * V^2
>> >>
>>
Resound> That does make a bit of difference, dunnit? I do wonder how
Resound> constant the energy dispersion of a helmet relative to
Resound> speed is though. Probably not a squared function though.
>> No idea, I'm not an engineer. I've just got basic physics under
>> my belt and I can remember some equations and Google what I can't
>>
Bleve> You also forget that forces work in directions. 35km/h
Bleve> horizontally is mostly irrelevant* when you fall down from 2m
Bleve> under the influence of gravity. A bike helmet won't do squat
Bleve> at 35km/h to dead stop, but that's not the point.
See post on vectors. The horizontal component can be far from irrelevant
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Bleve> Euan wrote:
>> >>>>> "Resound" == Resound <[email protected]>
>> writes:
>>
>> >> Bicycle helmets absorb kinetic energy (KE). The formula for
>> KE >> is:
>> >>
>> >> KE = 1/2 * M * V^2
>> >>
>>
Resound> That does make a bit of difference, dunnit? I do wonder how
Resound> constant the energy dispersion of a helmet relative to
Resound> speed is though. Probably not a squared function though.
>> No idea, I'm not an engineer. I've just got basic physics under
>> my belt and I can remember some equations and Google what I can't
>>
Bleve> You also forget that forces work in directions. 35km/h
Bleve> horizontally is mostly irrelevant* when you fall down from 2m
Bleve> under the influence of gravity. A bike helmet won't do squat
Bleve> at 35km/h to dead stop, but that's not the point.
See post on vectors. The horizontal component can be far from irrelevant
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
E
Euan
Guest
>>>>> "Claes" == Claes <[email protected]> writes:
Claes> Euan Wrote:
>> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>>
Theo> Resound wrote:
>> >> And, importantly, it's only recently that we've been moving at
>> >> greater than running speed. Hit the ground at 20kph and you're
>> >> okelydokely. Hit the ground at 40kph and you're much more
>> likely >> to break something important. Not always of course, but
>> doubling >> impact speed is always going to skew your results
>> more than a >> touch.
>>
Theo> Err, if you fall off your bike you will hit the ground at
Theo> approx 20km/h regardless of the speed at which you are
Theo> travelling. This is the design spec of bike helmets. Should
Theo> you have a horizontal velocity of 40 km/h you will still hit
Theo> the ground at 20km/h.
>> I don't think that's correct.
>>
>> When there are two or more velocities what we have a vectors. We
>> have the horizontal component (40km/h) and the vertical
>> component. The vector simplistically is the root of the sum of
>> the horizontal squared and the vertical squared.
>>
>> For the cited figures that gives a velocity of 44km/h on point of
>> impact.
>>
>> A combination of kinetic absorption and friction dissipates the
>> velocity.
Claes> Why do you get in to vectors when you do not know what they
Claes> mean? The vertical component of it, is what give you impact
Claes> against the ground, that is what the helmet should
Claes> absorb. The horizontal component gives rotation, you could
Claes> argue that the helmet makes that worse, since the radius of
Claes> the helmet is bigger than the head. You could also argue that
Claes> the friction of the helmet against the road is lower, and
Claes> that helps to minimise the rotation. It also gives road rash,
Claes> where the helmet does help. Again, if your horizontal
Claes> component is 50 km/h and you hit a boulder straight on, well,
Claes> helmet or not, you die.
I do know what vectors mean. I've demonstrated that perfectly well.
If I've erred with vectors you've not demonstrated where I've erred.
You're under the mistaken impression that only the vertical contributes
to the impact speed. You are wrong.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Claes> Euan Wrote:
>> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>>
Theo> Resound wrote:
>> >> And, importantly, it's only recently that we've been moving at
>> >> greater than running speed. Hit the ground at 20kph and you're
>> >> okelydokely. Hit the ground at 40kph and you're much more
>> likely >> to break something important. Not always of course, but
>> doubling >> impact speed is always going to skew your results
>> more than a >> touch.
>>
Theo> Err, if you fall off your bike you will hit the ground at
Theo> approx 20km/h regardless of the speed at which you are
Theo> travelling. This is the design spec of bike helmets. Should
Theo> you have a horizontal velocity of 40 km/h you will still hit
Theo> the ground at 20km/h.
>> I don't think that's correct.
>>
>> When there are two or more velocities what we have a vectors. We
>> have the horizontal component (40km/h) and the vertical
>> component. The vector simplistically is the root of the sum of
>> the horizontal squared and the vertical squared.
>>
>> For the cited figures that gives a velocity of 44km/h on point of
>> impact.
>>
>> A combination of kinetic absorption and friction dissipates the
>> velocity.
Claes> Why do you get in to vectors when you do not know what they
Claes> mean? The vertical component of it, is what give you impact
Claes> against the ground, that is what the helmet should
Claes> absorb. The horizontal component gives rotation, you could
Claes> argue that the helmet makes that worse, since the radius of
Claes> the helmet is bigger than the head. You could also argue that
Claes> the friction of the helmet against the road is lower, and
Claes> that helps to minimise the rotation. It also gives road rash,
Claes> where the helmet does help. Again, if your horizontal
Claes> component is 50 km/h and you hit a boulder straight on, well,
Claes> helmet or not, you die.
I do know what vectors mean. I've demonstrated that perfectly well.
If I've erred with vectors you've not demonstrated where I've erred.
You're under the mistaken impression that only the vertical contributes
to the impact speed. You are wrong.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
E
Euan
Guest
>>>>> "Bleve" == Bleve <[email protected]> writes:
ritcho> For example, a 20kg plate can be supported by balancing it
ritcho> on your head, but put a nail in the centre of the plate and
ritcho> you'll pierce a nice hole in your head if you try to balance
ritcho> it in the same way. This example says nothing about
ritcho> velocity, but something about the distribution of force...
>> That's correct, force. That's different from kinetic energy and
>> depending what you're trying to calculate there are many
>> different equations.
Bleve> One of the advantages of a helmet (or any device designed to
Bleve> lessen point impacts) is that pressure (which does a lot of
Bleve> damage, eg nails cv dinner plates) is reduced. That square
Bleve> law you're thinking about wrt KE, well, pressure =
Bleve> force/area, and area is a square function also. The rest is
Bleve> left as an exercise to the reader.
Agreed, however if a device has only X amount of kinetic absorption the
rest has to go somewhere.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
ritcho> For example, a 20kg plate can be supported by balancing it
ritcho> on your head, but put a nail in the centre of the plate and
ritcho> you'll pierce a nice hole in your head if you try to balance
ritcho> it in the same way. This example says nothing about
ritcho> velocity, but something about the distribution of force...
>> That's correct, force. That's different from kinetic energy and
>> depending what you're trying to calculate there are many
>> different equations.
Bleve> One of the advantages of a helmet (or any device designed to
Bleve> lessen point impacts) is that pressure (which does a lot of
Bleve> damage, eg nails cv dinner plates) is reduced. That square
Bleve> law you're thinking about wrt KE, well, pressure =
Bleve> force/area, and area is a square function also. The rest is
Bleve> left as an exercise to the reader.
Agreed, however if a device has only X amount of kinetic absorption the
rest has to go somewhere.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Study, papers, data, research, blah, blah, blah...
Ask/study all the people who have been in serious accidents (up to a point. some are just so horrific nothing woulda saved em ) and they will ALL tell you their helmet saved em from serious head injuries.
This fanciful stuff about helmets decreasing rider numbers is tripe. cycling numbers were dropping at the same rate before the helmet intro. Just another convenient tweak of facts to suit an agenda.
One thing not mentioned so far...
When your head strikes a surface it tends to 'stop' causing neck/etc injuries.
Helmet standards were reviewed in he 90's to ensure they were not that exposed styrafoam stuff or covered in cloth-stuff and given 'slippery' outer shells so if you hit the deck your head keeps movig along with the rest of you
BOTTOM LINE
If you wear a helmet, WHATEVER!
If you dont.... WHATEVER!!!
It amazes me the fervour with which people can lather themselves into to argue against helmet use, and yet ANYONE who has been in a serious spill doesnt. Could it be they are speaking from such a strange position as 'experience' ?
Ask/study all the people who have been in serious accidents (up to a point. some are just so horrific nothing woulda saved em
) and they will ALL tell you their helmet saved em from serious head injuries.This fanciful stuff about helmets decreasing rider numbers is tripe. cycling numbers were dropping at the same rate before the helmet intro. Just another convenient tweak of facts to suit an agenda.
One thing not mentioned so far...
When your head strikes a surface it tends to 'stop' causing neck/etc injuries.
Helmet standards were reviewed in he 90's to ensure they were not that exposed styrafoam stuff or covered in cloth-stuff and given 'slippery' outer shells so if you hit the deck your head keeps movig along with the rest of you
BOTTOM LINE
If you wear a helmet, WHATEVER!
If you dont.... WHATEVER!!!
It amazes me the fervour with which people can lather themselves into to argue against helmet use, and yet ANYONE who has been in a serious spill doesnt. Could it be they are speaking from such a strange position as 'experience' ?
E
Euan
Guest
>>>>> "Bleve" == Bleve <[email protected]> writes:
Bleve> heh, there's a paper with an axe to grind
Just about every paper published has an axe to grind. A paper doesn't
get written unless someone's trying to prove something.
Bleve> Interestingly, it cites stats that somewhere around 30-45% of
Bleve> teenagers and adults stopped riding in the two years after
Bleve> helmets were made compulsory - but also states that there was
Bleve> a 35-70% reduction in head injurys reported.
Bleve> Now, I didn't do super well at Uni when doing maths (I got to
Bleve> do a few subjects rather more than once ), but I'd find it
Bleve> difficult to draw any conclusions from that (and the author
Bleve> admits, not very good quality research) that didn't suggest
Bleve> that there was a significant improvement.
Bleve> I'm intrigued as to the use of pedestrians as a control
Bleve> group, and the reduction of head injuries there that seem to
Bleve> match. There's no attempt to suggest why peds were showing
Bleve> up less at hospitals with serious head injuries. Did
Bleve> something change in the water in 1985?
Indeed, so if pedestrians head injury rate is going down in sympathy
with that of cyclists, how does that prove that helmets have been
effective in reducing the incidence of head injury?
Bleve> Now, Euan, read the second last paragraph. I'll save you the
Bleve> effort of finding it : "helmets undoutably prevent wounds to
Bleve> the head". My take on that paper is that it's desperatly
Bleve> looking for ways to show that helmets don't work, and even
Bleve> then, it has to admit it in the end, where no-one will look,
Bleve> after muddying up a lot of already very muddy statistics, and
Bleve> somehow claiming that white, educated people have less
Bleve> prangs, not that they're more likely to wear a lid. I didn't
Bleve> see anything in the paper that matched if people presenting
Bleve> with HI's were actually *wearing* their lids, but I may have
Bleve> missed that bit, if it's in there somewhere?
Fair point, however it would be a long bow to suppose that all the
admissions were not wearing helmets when compliance with the law has
gone up to 85%. It's also possible that that data isn't available.
It's only recently in the UK that those statistics have started to be
collected, can't speak for here.
I'm not disputing that helmets offer some protection in some cases. I'm
stating two things:
1) Helmets effectiveness is vastly over-rated by the majority of
practicing cyclists.
2) Compulsion reduced the number cycling and may still be a barrier to
cycling.
So let's stop batting the ``helmet saved my life'' stories. I've
proved that I believe I've had significant head accidents and walked
away relatively scot free, you've proved that you believe wearing a
helmet saved you from significant head trauma, so let's move on and
debate 1) and 2).
Bleve> It also harps on about decining numbers of riders as a safety
Bleve> concern. I say that in the long term numbers of people
Bleve> riding bikes has probably not changed significantly because
Bleve> of helmet law, but *may* have changed becase now joe average
Bleve> can afford two cars. Or maybe not. But you don't know either
Bleve> way.
It's one of these things that's hard to pin down. I know my
mother-in-law won't consider cycling because a helmet will muss up here
hair. I'd have thought the wind would have done that quite adequately
but there you go.
It's one of those imponderables that we'll never know. I suspect if
compulsion were lifted we'd see more people cycling. You believe
otherwise.
Bleve> At the end of the day, that paper is all guesswork.
Which bits are guesswork? The time-series data regarding head injury
pre and post compulsion compared with that of random breath testing
being introduced seems quite significant to me.
Bleve> add bugger-all weight (mine's 200-odd grams and isn't
Bleve> sticking out like a pendulum, my hair, when wet and long,
Bleve> probably weighed more ...) compared to motorbike helmets
Bleve> which are very heavy and may well increase the injury rate
Bleve> for rotational force crashes. I reckon the tradeoff is so
Bleve> minor that the inconvenience of a helmet (worrying about
Bleve> helmet-head? That wind will blow your hair all over the shop
Bleve> anyway ....
Hmm, guess who's replying to the post as he's reading it ;-) See
earlier.
Bleve> you'll still have to brush it if it's an issue) is far
Bleve> outweighed by the (even if it's very slim) reduction in the
Bleve> severity of some classes of head injury.
It's not the injury reduction I'm arguing, it's the reduction in the
number of cyclists. I believe helmet compulsion is a barrier and I've
yet to be convinced otherwise.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Bleve> heh, there's a paper with an axe to grind
Just about every paper published has an axe to grind. A paper doesn't
get written unless someone's trying to prove something.
Bleve> Interestingly, it cites stats that somewhere around 30-45% of
Bleve> teenagers and adults stopped riding in the two years after
Bleve> helmets were made compulsory - but also states that there was
Bleve> a 35-70% reduction in head injurys reported.
Bleve> Now, I didn't do super well at Uni when doing maths (I got to
Bleve> do a few subjects rather more than once
), but I'd find itBleve> difficult to draw any conclusions from that (and the author
Bleve> admits, not very good quality research) that didn't suggest
Bleve> that there was a significant improvement.
Bleve> I'm intrigued as to the use of pedestrians as a control
Bleve> group, and the reduction of head injuries there that seem to
Bleve> match. There's no attempt to suggest why peds were showing
Bleve> up less at hospitals with serious head injuries. Did
Bleve> something change in the water in 1985?
Indeed, so if pedestrians head injury rate is going down in sympathy
with that of cyclists, how does that prove that helmets have been
effective in reducing the incidence of head injury?
Bleve> Now, Euan, read the second last paragraph. I'll save you the
Bleve> effort of finding it : "helmets undoutably prevent wounds to
Bleve> the head". My take on that paper is that it's desperatly
Bleve> looking for ways to show that helmets don't work, and even
Bleve> then, it has to admit it in the end, where no-one will look,
Bleve> after muddying up a lot of already very muddy statistics, and
Bleve> somehow claiming that white, educated people have less
Bleve> prangs, not that they're more likely to wear a lid. I didn't
Bleve> see anything in the paper that matched if people presenting
Bleve> with HI's were actually *wearing* their lids, but I may have
Bleve> missed that bit, if it's in there somewhere?
Fair point, however it would be a long bow to suppose that all the
admissions were not wearing helmets when compliance with the law has
gone up to 85%. It's also possible that that data isn't available.
It's only recently in the UK that those statistics have started to be
collected, can't speak for here.
I'm not disputing that helmets offer some protection in some cases. I'm
stating two things:
1) Helmets effectiveness is vastly over-rated by the majority of
practicing cyclists.
2) Compulsion reduced the number cycling and may still be a barrier to
cycling.
So let's stop batting the ``helmet saved my life'' stories. I've
proved that I believe I've had significant head accidents and walked
away relatively scot free, you've proved that you believe wearing a
helmet saved you from significant head trauma, so let's move on and
debate 1) and 2).
Bleve> It also harps on about decining numbers of riders as a safety
Bleve> concern. I say that in the long term numbers of people
Bleve> riding bikes has probably not changed significantly because
Bleve> of helmet law, but *may* have changed becase now joe average
Bleve> can afford two cars. Or maybe not. But you don't know either
Bleve> way.
It's one of these things that's hard to pin down. I know my
mother-in-law won't consider cycling because a helmet will muss up here
hair. I'd have thought the wind would have done that quite adequately
but there you go.
It's one of those imponderables that we'll never know. I suspect if
compulsion were lifted we'd see more people cycling. You believe
otherwise.
Bleve> At the end of the day, that paper is all guesswork.
Which bits are guesswork? The time-series data regarding head injury
pre and post compulsion compared with that of random breath testing
being introduced seems quite significant to me.
Bleve> add bugger-all weight (mine's 200-odd grams and isn't
Bleve> sticking out like a pendulum, my hair, when wet and long,
Bleve> probably weighed more ...) compared to motorbike helmets
Bleve> which are very heavy and may well increase the injury rate
Bleve> for rotational force crashes. I reckon the tradeoff is so
Bleve> minor that the inconvenience of a helmet (worrying about
Bleve> helmet-head? That wind will blow your hair all over the shop
Bleve> anyway ....
Hmm, guess who's replying to the post as he's reading it ;-) See
earlier.
Bleve> you'll still have to brush it if it's an issue) is far
Bleve> outweighed by the (even if it's very slim) reduction in the
Bleve> severity of some classes of head injury.
It's not the injury reduction I'm arguing, it's the reduction in the
number of cyclists. I believe helmet compulsion is a barrier and I've
yet to be convinced otherwise.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
E
Euan
Guest
>>>>> "Bleve" == Bleve <[email protected]> writes:
Bleve> Euan wrote:
>> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>>
Theo> Resound wrote:
>> >> And, importantly, it's only recently that we've been moving at
>> >> greater than running speed. Hit the ground at 20kph and you're
>> >> okelydokely. Hit the ground at 40kph and you're much more
>> likely >> to break something important. Not always of course, but
>> doubling >> impact speed is always going to skew your results
>> more than a >> touch.
>>
Theo> Err, if you fall off your bike you will hit the ground at
Theo> approx 20km/h regardless of the speed at which you are
Theo> travelling. This is the design spec of bike helmets. Should
Theo> you have a horizontal velocity of 40 km/h you will still hit
Theo> the ground at 20km/h.
>> I don't think that's correct.
Bleve> It is, and you even say why below
>> When there are two or more velocities what we have a vectors. We
>> have the horizontal component (40km/h) and the vertical
>> component. The vector simplistically is the root of the sum of
>> the horizontal squared and the vertical squared.
>>
>> For the cited figures that gives a velocity of 44km/h on point of
>> impact.
>>
>> A combination of kinetic absorption and friction dissipates the
>> velocity.
Bleve> Indeed it does. Friction (and tumbling losses) absorbs (read
Bleve> - grinds ...) the horizontal component, and the padding/shell
Bleve> fracture/compaction absorbs the vertical.
Bleve> Get a pumpkin, put it on the end of a 2m pole. Tip it onto
Bleve> the ground* from ~2m, and then push it along the ground, and
Bleve> see what happens to it. Then, put a helmet on another
Bleve> pumpkin and try the same experiment. Compare the two
Bleve> pumpkins. Imagine the surface of the pumpkin is your skin
Bleve> and the contents, your brain.
It is exceedingly simplistic to suggest that the horizontal component is
dissipated through friction alone. The impact speed is still what the
vectors say it is and a significant proportion of that is absorbed on
impact.
Bleve> Now, what were you saying again? Helmets don't work, that's
Bleve> it, I remember now
I haven't said they don't work, just that they don't work nearly as well
as a lot of people think.
Bleve> Judo training would help eh?
I've not mentioned judo, that was someone else and I don't agree with
it. I've heard that wearing glasses helps as one's more inclined to
instinctively protect the head. Can't say I've found that to be the case
;-)
Bleve> The helmet worked. It broke, my head didn't. I didn't even
Bleve> bleed my own blood. Get it?
I get that you think the helmet saved you from significant injury, you
may be correct. We'll never know.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Bleve> Euan wrote:
>> >>>>> "Theo" == Theo Bekkers <[email protected]> writes:
>>
Theo> Resound wrote:
>> >> And, importantly, it's only recently that we've been moving at
>> >> greater than running speed. Hit the ground at 20kph and you're
>> >> okelydokely. Hit the ground at 40kph and you're much more
>> likely >> to break something important. Not always of course, but
>> doubling >> impact speed is always going to skew your results
>> more than a >> touch.
>>
Theo> Err, if you fall off your bike you will hit the ground at
Theo> approx 20km/h regardless of the speed at which you are
Theo> travelling. This is the design spec of bike helmets. Should
Theo> you have a horizontal velocity of 40 km/h you will still hit
Theo> the ground at 20km/h.
>> I don't think that's correct.
Bleve> It is, and you even say why below
>> When there are two or more velocities what we have a vectors. We
>> have the horizontal component (40km/h) and the vertical
>> component. The vector simplistically is the root of the sum of
>> the horizontal squared and the vertical squared.
>>
>> For the cited figures that gives a velocity of 44km/h on point of
>> impact.
>>
>> A combination of kinetic absorption and friction dissipates the
>> velocity.
Bleve> Indeed it does. Friction (and tumbling losses) absorbs (read
Bleve> - grinds ...) the horizontal component, and the padding/shell
Bleve> fracture/compaction absorbs the vertical.
Bleve> Get a pumpkin, put it on the end of a 2m pole. Tip it onto
Bleve> the ground* from ~2m, and then push it along the ground, and
Bleve> see what happens to it. Then, put a helmet on another
Bleve> pumpkin and try the same experiment. Compare the two
Bleve> pumpkins. Imagine the surface of the pumpkin is your skin
Bleve> and the contents, your brain.
It is exceedingly simplistic to suggest that the horizontal component is
dissipated through friction alone. The impact speed is still what the
vectors say it is and a significant proportion of that is absorbed on
impact.
Bleve> Now, what were you saying again? Helmets don't work, that's
Bleve> it, I remember now
I haven't said they don't work, just that they don't work nearly as well
as a lot of people think.
Bleve> Judo training would help eh?
I've not mentioned judo, that was someone else and I don't agree with
it. I've heard that wearing glasses helps as one's more inclined to
instinctively protect the head. Can't say I've found that to be the case
;-)
Bleve> The helmet worked. It broke, my head didn't. I didn't even
Bleve> bleed my own blood. Get it?
I get that you think the helmet saved you from significant injury, you
may be correct. We'll never know.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
E
Euan
Guest
>>>>> "Bleve" == Bleve <[email protected]> writes:
Bleve> Except in extreme cases (degloving etc) hand injuries in bike
Bleve> accidents are minor scrapes or abrasions (painful, but not
Bleve> long-term incapacitating), and occasional broken bones.
Bleve> Broken fingers heal reasonably well (my hands still work,
Bleve> I've busted a few!). That said, I very rarely ride without
Bleve> gloves on on bitumen or concrete.
I thought the main purpose of gloves was shock absorption while riding?
That's why I wear mine, I notice if I don't have them on.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
Bleve> Except in extreme cases (degloving etc) hand injuries in bike
Bleve> accidents are minor scrapes or abrasions (painful, but not
Bleve> long-term incapacitating), and occasional broken bones.
Bleve> Broken fingers heal reasonably well (my hands still work,
Bleve> I've busted a few!). That said, I very rarely ride without
Bleve> gloves on on bitumen or concrete.
I thought the main purpose of gloves was shock absorption while riding?
That's why I wear mine, I notice if I don't have them on.
--
Cheers | ~~ __@
Euan | ~~ _-\<,
Melbourne, Australia | ~ (*)/ (*)
D
dave
Guest
Bleve wrote:
> dave wrote:
>
>>Gemma_k wrote:
>>
>>>"Bleve" <[email protected]> wrote in message
>>>news:[email protected]...
>>>
>>>
>>>>Euan wrote:
>>>>
>>>>
>>>>>>>>>>"Bob" == Bob <[email protected]> writes:
>>>>>
>>>>> Bob> The only link is that mandatory wearing of helmets, at one
>>>>> Bob> point in time, discouraged cyclists, reducing cyclist
>>>>> Bob> numbers. I think everyone is over that by now - does it really
>>>>> Bob> discourage anyone anymore?
>>>>>
>>>>>Absolutely. It's a hot and smelly inconvenience which is off-putting to
>>>>>the fashion conscious.
>>>>
>>>>Stackhats went out in, oh, 1980? Modern helmets are light, well
>>>>ventilated and comfortable.
>>>>
>>>
>>>You miss the point. It doesn't matter how good a helmet is to wear, or how
>>>safe you feel in one, or how many vents there are or what kind of hairstyle
>>>you have. It's all about the choice of whther you WANT to wear a helmet,
>>>rather than mandating that you do....
>>>Gemma
>>>
>>>
>>
>>Yup
>>
>>And if you wanted sensible effective legislation mandating stuff for
>>safety (and I dont) Then legislate for gloves, your hands always hit
>>the road.
>
>
> Except in extreme cases (degloving etc) hand injuries in
> bike accidents are minor scrapes or abrasions (painful, but not
> long-term
> incapacitating), and occasional broken bones.
> Broken fingers heal reasonably well (my hands still work, I've
> busted a few!). That said, I very rarely ride without gloves on on
> bitumen or concrete.
>
> As always, where you draw the line is arbitary
>
Yeah of course. But lots of nerves in hands.. always painful and really
easily avoided. And of course I am not in favour of any such legislation.
> dave wrote:
>
>>Gemma_k wrote:
>>
>>>"Bleve" <[email protected]> wrote in message
>>>news:[email protected]...
>>>
>>>
>>>>Euan wrote:
>>>>
>>>>
>>>>>>>>>>"Bob" == Bob <[email protected]> writes:
>>>>>
>>>>> Bob> The only link is that mandatory wearing of helmets, at one
>>>>> Bob> point in time, discouraged cyclists, reducing cyclist
>>>>> Bob> numbers. I think everyone is over that by now - does it really
>>>>> Bob> discourage anyone anymore?
>>>>>
>>>>>Absolutely. It's a hot and smelly inconvenience which is off-putting to
>>>>>the fashion conscious.
>>>>
>>>>Stackhats went out in, oh, 1980? Modern helmets are light, well
>>>>ventilated and comfortable.
>>>>
>>>
>>>You miss the point. It doesn't matter how good a helmet is to wear, or how
>>>safe you feel in one, or how many vents there are or what kind of hairstyle
>>>you have. It's all about the choice of whther you WANT to wear a helmet,
>>>rather than mandating that you do....
>>>Gemma
>>>
>>>
>>
>>Yup
>>
>>And if you wanted sensible effective legislation mandating stuff for
>>safety (and I dont) Then legislate for gloves, your hands always hit
>>the road.
>
>
> Except in extreme cases (degloving etc) hand injuries in
> bike accidents are minor scrapes or abrasions (painful, but not
> long-term
> incapacitating), and occasional broken bones.
> Broken fingers heal reasonably well (my hands still work, I've
> busted a few!). That said, I very rarely ride without gloves on on
> bitumen or concrete.
>
> As always, where you draw the line is arbitary
>
Yeah of course. But lots of nerves in hands.. always painful and really
easily avoided. And of course I am not in favour of any such legislation.
D
dave
Guest
flyingdutch wrote:
> Study, papers, data, research, blah, blah, blah...
>
> Ask/study all the people who have been in serious accidents (up to a
> point. some are just so horrific nothing woulda saved em ) and they
> will ALL tell you their helmet saved em from serious head injuries.
>
> This fanciful stuff about helmets decreasing rider numbers is tripe.
> cycling numbers were dropping at the same rate before the helmet intro.
> Just another convenient tweak of facts to suit an agenda.
>
> One thing not mentioned so far...
> When your head strikes a surface it tends to 'stop' causing neck/etc
> injuries.
> Helmet standards were reviewed in he 90's to ensure they were not that
> exposed styrafoam stuff or covered in cloth-stuff and given 'slippery'
> outer shells so if you hit the deck your head keeps movig along with
> the rest of you
Absolutely
And before that helmets undoubtably killed a few pople.
>
> BOTTOM LINE
>
> If you wear a helmet, WHATEVER!
>
> If you dont.... WHATEVER!!!
>
> It amazes me the fervour with which people can lather themselves into
> to argue against helmet use, and yet ANYONE who has been in a serious
> spill doesnt. Could it be they are speaking from such a strange
> position as 'experience' ?
>
>
Ummm I have been n lots of spills. One of the things is that most of
the people who say the helmet saved their life are unconving to say the
least. It may have saved their ear.. That I would believe.
And I am mildly pro helmet very anti legislation.
> Study, papers, data, research, blah, blah, blah...
>
> Ask/study all the people who have been in serious accidents (up to a
> point. some are just so horrific nothing woulda saved em
) and they> will ALL tell you their helmet saved em from serious head injuries.
>
> This fanciful stuff about helmets decreasing rider numbers is tripe.
> cycling numbers were dropping at the same rate before the helmet intro.
> Just another convenient tweak of facts to suit an agenda.
>
> One thing not mentioned so far...
> When your head strikes a surface it tends to 'stop' causing neck/etc
> injuries.
> Helmet standards were reviewed in he 90's to ensure they were not that
> exposed styrafoam stuff or covered in cloth-stuff and given 'slippery'
> outer shells so if you hit the deck your head keeps movig along with
> the rest of you
Absolutely
And before that helmets undoubtably killed a few pople.
>
> BOTTOM LINE
>
> If you wear a helmet, WHATEVER!
>
> If you dont.... WHATEVER!!!
>
> It amazes me the fervour with which people can lather themselves into
> to argue against helmet use, and yet ANYONE who has been in a serious
> spill doesnt. Could it be they are speaking from such a strange
> position as 'experience' ?
>
>
Ummm I have been n lots of spills. One of the things is that most of
the people who say the helmet saved their life are unconving to say the
least. It may have saved their ear.. That I would believe.
And I am mildly pro helmet very anti legislation.
B
Bleve
Guest
Euan wrote:
> I thought the main purpose of gloves was shock absorption while riding?
> That's why I wear mine, I notice if I don't have them on.
Nah, it's to give you funky tanlines
> I thought the main purpose of gloves was shock absorption while riding?
> That's why I wear mine, I notice if I don't have them on.
Nah, it's to give you funky tanlines
B
Bleve
Guest
Euan wrote:
> >>>>> "Bleve" == Bleve <[email protected]> writes:
>
> ritcho> For example, a 20kg plate can be supported by balancing it
> ritcho> on your head, but put a nail in the centre of the plate and
> ritcho> you'll pierce a nice hole in your head if you try to balance
> ritcho> it in the same way. This example says nothing about
> ritcho> velocity, but something about the distribution of force...
> >> That's correct, force. That's different from kinetic energy and
> >> depending what you're trying to calculate there are many
> >> different equations.
>
> Bleve> One of the advantages of a helmet (or any device designed to
> Bleve> lessen point impacts) is that pressure (which does a lot of
> Bleve> damage, eg nails cv dinner plates) is reduced. That square
> Bleve> law you're thinking about wrt KE, well, pressure =
> Bleve> force/area, and area is a square function also. The rest is
> Bleve> left as an exercise to the reader.
>
> Agreed, however if a device has only X amount of kinetic absorption the
> rest has to go somewhere.
Of course. That's a given. There's a tradeoff between helmet safety
and
weight, size and effectiveness. Tempered also by the body's ability or
otherwise to survive greater forces even if one part is well protected.
Helmet's aren't perfect, and I don't think anyone is saying they are.
> >>>>> "Bleve" == Bleve <[email protected]> writes:
>
> ritcho> For example, a 20kg plate can be supported by balancing it
> ritcho> on your head, but put a nail in the centre of the plate and
> ritcho> you'll pierce a nice hole in your head if you try to balance
> ritcho> it in the same way. This example says nothing about
> ritcho> velocity, but something about the distribution of force...
> >> That's correct, force. That's different from kinetic energy and
> >> depending what you're trying to calculate there are many
> >> different equations.
>
> Bleve> One of the advantages of a helmet (or any device designed to
> Bleve> lessen point impacts) is that pressure (which does a lot of
> Bleve> damage, eg nails cv dinner plates) is reduced. That square
> Bleve> law you're thinking about wrt KE, well, pressure =
> Bleve> force/area, and area is a square function also. The rest is
> Bleve> left as an exercise to the reader.
>
> Agreed, however if a device has only X amount of kinetic absorption the
> rest has to go somewhere.
Of course. That's a given. There's a tradeoff between helmet safety
and
weight, size and effectiveness. Tempered also by the body's ability or
otherwise to survive greater forces even if one part is well protected.
Helmet's aren't perfect, and I don't think anyone is saying they are.
D
David Trudgett
Guest
"Bleve" <[email protected]> writes:
> David Trudgett wrote:
>
>> Option 1: Compulsory xyz
>> Option 2: Refuse healthcare
>>
>> Unfortunately, both your options are unChristian.
>
> I am not a christian.
You must have missed my replies to two others on this general subject;
in particular, this one:
http://groups.google.com.au/group/a...65ad1/147b457d6f66d396&hl=en#147b457d6f66d396
If violence against others is OK in your religion because the ends
justify the means, or if in your religion it is OK to withhold medical
care from those who need it, whether or not through their own
stupidity, then feel free to ignore my comments.
On the other hand, if this is not the case, then you have no grounds
for complaint.
>
> This is aus.bicyles, religious argument really doesn't
> belong, eh?
>
I've already replied to that, too:
"I don't think it appropriate to exclude religion from
life. Religion *is* life, you know."
If religion is something you do on Sunday mornings, then it is not a
religion, it's a hobby.
If a Christian goes to church on Sunday and professes to oppose all
evil and violence, but then goes to work on Monday and condemns a man
to death or imprisonment, then that Christian is a hypocrite. Christ had
a lot to say about such people; and so did Leo Tolstoy, by the by (see
sig).
On the other hand, if your religious beliefs include a belief in the
goodness of violence (which includes denying medical care to those who
need it), then just come right out and say it.
David
--
David Trudgett
http://www.zeta.org.au/~wpower/
Only let men cease to be hypocrites, and they would at once see that
this cruel social organization, which holds them in bondage, and is
represented to them as something stable, necessary, and ordained of
God, is already tottering and is only propped up by the falsehood of
hypocrisy, with which we, and others like us, support it.
-- Leo Tolstoy, "The Kingdom of God is Within You"
> David Trudgett wrote:
>
>> Option 1: Compulsory xyz
>> Option 2: Refuse healthcare
>>
>> Unfortunately, both your options are unChristian.
>
> I am not a christian.
You must have missed my replies to two others on this general subject;
in particular, this one:
http://groups.google.com.au/group/a...65ad1/147b457d6f66d396&hl=en#147b457d6f66d396
If violence against others is OK in your religion because the ends
justify the means, or if in your religion it is OK to withhold medical
care from those who need it, whether or not through their own
stupidity, then feel free to ignore my comments.
On the other hand, if this is not the case, then you have no grounds
for complaint.
>
> This is aus.bicyles, religious argument really doesn't
> belong, eh?
>
I've already replied to that, too:
"I don't think it appropriate to exclude religion from
life. Religion *is* life, you know."
If religion is something you do on Sunday mornings, then it is not a
religion, it's a hobby.
If a Christian goes to church on Sunday and professes to oppose all
evil and violence, but then goes to work on Monday and condemns a man
to death or imprisonment, then that Christian is a hypocrite. Christ had
a lot to say about such people; and so did Leo Tolstoy, by the by (see
sig).
On the other hand, if your religious beliefs include a belief in the
goodness of violence (which includes denying medical care to those who
need it), then just come right out and say it.
David
--
David Trudgett
http://www.zeta.org.au/~wpower/
Only let men cease to be hypocrites, and they would at once see that
this cruel social organization, which holds them in bondage, and is
represented to them as something stable, necessary, and ordained of
God, is already tottering and is only propped up by the falsehood of
hypocrisy, with which we, and others like us, support it.
-- Leo Tolstoy, "The Kingdom of God is Within You"
