Anybody not wear a helmet? Discuss....

Christophe3967

bikesdontfloat wrote:

I found this on the BMJ website for those of you who wear a helmet when cycling but not when walking yet consider those who choose not to wear a helmet when cycling as taking a reckless risk. Thoroughly tongue in cheek but making a serious point - normal, everyday cycling is not especially risky and as such requires no more safety equipment than walking.
Those who wear hi-vis, lights and a helmet while walking to the shops are, of course, still perfectly entitled to berate any cyclist who doesn't wear a helmet

Quite so. Its also worth remembering that, as with many debates e.g. global warming, there are vested interests that may try to skew the argument. In this case we have the multi-million cycling helmet industry in league with the cycling authorities. This makes it impossible to race or enter most sportives without wearing a helmet. At least we didn't need them for the HOTA last weekend. Before this rule, a significant number of professional road cyclists chose not to wear helmets, and many still don't whilst training.

always_tyred

Always Tyred wrote:

jashburnham wrote:

facemunk wrote:

I'm a deaf (hearing impaired) cyclist and I don't wear a helmet either. Should I be shot?

Most likely. Damn your selfishness man, think of your responsibilities. :roll:

Did you the Tweed run btw?

I suspect, dear Jash, that in 25 years, when you still regard yourself as a tart, you may inadertently be wearing the equivalent in clothing to the Tweed run people who you so ridicule today. Oh how the young cyclists of 2034 will laugh at the bald, middle aged man in his silly red and white outfit.

As I recall its a group of cyclists who prefer things as they were rather than as they are. Its its hard to tell if anyone actually takes it seriously from here. But given that people still take Morris dancing seriously, anything is possible. You did once propose that it might be of interest to me, which I didn't regard as a compliment.

Sorry about the bald thing; wild stab in the dark.

always_tyred

"The statistical wrangle over the effectiveness of helmets is actually a side issue; what we need people in authority to understand is that cycle helmets inevitably damage public health. Even for cyclists on Britain's roads, the health benefits exceed the risks by a factor of 20.7 The health benefits of cycling are so great---and the health injuries from driving so great8---that not cycling is really dangerous. By telling people that they need helmets for an activity that for a century has been regarded as "safe"---and in fact has a fine safety record---you inevitably engender the impression that cycling must have become more dangerous than driving and walking. That deters cycling. That reduces cyclists' presence on the roads. That increases the risk of death. And if wild claims about helmets saving lives are published in the media,9 helmet users are bound to feel overly secure, thus compromising their one vital safety feature---a sense of caution. 10 11 In addition, over time most people--- and especially parents---will come to believe that it is wearing a helmet that matters, not acquiring skilful technique.12 These effects have been noted in every country where helmets have come into general use, including the United Kingdom.13 Millions will die early because they did not cycle. "

---

Did anyone actually read this? I get really annoyed, because to get a publication as a chemist, you have to do some work, you know like about 2 years in the lab. This bloke has just pontificated into a computer and some nob has published it.

Remember me getting irritable about the "helmets make you less safe" argument? Here it is in all its glory. The citations 10-13 just so you know, point to a study on impact absorption by cycle helmet (which therefore appears to be a misplaced citation because it doesn't relate to the text) and 3 websites written by some other blokes who have thought about cycle helmets a bit.

So really, its an opinion, with some hyperlinks to some other people who share the same opinion. I bet he puts this article on his CV. I should put bikeradar on my CV. PhD chemist, over 1800 publications.

(For the avoidance of doubt - it is possible to share the sentiment that the sedentary majority would be less of a drain on resources if they moved around a bit more, without agreeing that cycle helmets are the great corporate evil keeping everyone on the sofa).

greg66_tri_v2.0

Always Tyred wrote:

This bloke has just pontificated into a computer and some nob has published it.

This surprises you? Welcome to the internet.

There's a reason I add, after some facetious and obviously wildly implausible bullsh!t I've just made up and posted here "I think I read that on the internet somewhere". There's no filter on what gets onto the internet. There's no peer review. There's just millions of mostly stupid screaming voices clammering for attention. Put up a page of crap that's nicely presented and you'll find a sizeable section of readership will think it's fcuking gospel. Everyone's allowed a voice on the internet. Not nearly as many have worked out that someone with a voice isn't necessarily worth listening to.

Case in point: the peckerhead on R4 this morning. He said he hadn't given his kids the MMR jabs because he thought it was harmful to give them three jabs. "Have you given them the jabs singularly?"
"No. Because they'e had measles". [Yeah, that works]
"Did the stories about the MMR vaccine influence you"
"Yes. If there's the slightest seed of a doubt I'm not going to chance my children" [so having no innoculation gives 100% safety against getting a disease?]
"What about the greater good: it's better to eliminate diseases through innoculation"
"If everyone's innoculated and no one's fighting these diseases naturally that has just as detrimental an effect." [fcuk this. Put that man on a rocket to the Sun. Now].

I will bet you any sum you care to name that that person had fortified his views with "research" done on the internet.

Cunobelin

The interesting thing that this case highlights two things that are frequently denied...

1. Helmets are not designed or contribute at more than 12 mph
2. Rotational injuries occur (and can be contributed to by helmets.

always_tyred

Greg66 wrote:

Always Tyred wrote:

This bloke has just pontificated into a computer and some nob has published it.

This surprises you? Welcome to the internet.

Normally not in the least, but this was a British Medical Journal, peer reviewed pontification. Its disturbing because it provides a certification of the content, to be wheeled out by trusting people, such as the guy who posted it, who are then content in their knowledge that there are "facts and figures" to support their decision.

He compares cycling and walking by the mile, and compares cycling and driving by the hour.

He doesn't seem to make any comment on the severity of potential injury (which is like comparing the risk of hurting yourself from a fall from a first floor window and to a 5th floor window - if you make the stats binary, injury or not, its like changing the contrast on your monitor - black becomes white, or vice versa).

He does little to normalise pedestrian accidents, for example comparing number of trips up and down stairs vs. number of trips by bicycle; he simply compares the total number of injuries. I'm a keen cyclist and even I use the stairs far more often.

He plucks out only the stats of cyclists spontaneously falling over, and omits the stats of cyclist being hit by vehicles.

He compares the population of drivers to a population of older, experienced cyclists who don't actually exist, to suggest that if they did exist, cycling would be safe. To make matters worse, he does this because he is arguing that motorists are better trained and more experienced (presumably forgetting that the reason his cycling stats under discussion suggest what they do is becuase he's discounted all of the careless motorist induced statistics).

Its annoying that some other over paid puffed up medics haven't, in their great wisdom, spotted any of this. The article is no better than Alan Hansen's musings as to why Rafa has lost the plot, where he will pull up stats of number of substitutions and squad changes without commenting on how many were the result of injuries.

I don't much mind the decision not to wear a helmet but I get annoyed when people believe that somehow, all of the intuitive benefits to wearing a helmet that even a child could understand are in fact the other way around (and only non helmet wearers are capable of understanding this complex argument).

Its no different to motorists who argue that, not withstanding the squared relationship of speed to energy, speed doesn't kill.

Make your decisions, chaps, by all means. I respect the right not to wear a helmet. But don't, please, make your decision on deluded and spurious reasoning.

alfablue

Peer review in medical journals is no guarantee of validity or trustworthiness, whilst they claim to reject papers with "serious scientific flaws" the process still allows many articles that have methodological or other problems. No reader should accept any findings without some critical appraisal of their own (as you have done AT). Although articles may have flaws they can make a contribution to debate and the body of knowledge. The last journal I published in included a comment by one of the reviewers at the end (which shocked me a bit!) but it assists the reader in making a more informed appraisal for themselves. Unfortunately, those with vested interests, axes to grind, etc. can pluck favourable findings from these articles and build their own fallacious arguements, and as suggested above, the less aware readers on the internet will convert these in to "facts" for their own arguments, often compounding the flaws and misrepresentations from the original sources without critique. Caveat emptor and all that!

always_tyred

Cunobelin wrote:

The interesting thing that this case highlights two things that are frequently denied...

1. Helmets are not designed or contribute at more than 12 mph
2. Rotational injuries occur (and can be contributed to by helmets.

No one denies (2), they simply question the severity of the increased risk of this type of injury (its not as though it doesn't happen when you aren't wearing a helmet for example). There aren't any data that I've seen to support the supposition that this is a problem that outweights the benefits of helmets to protect against impat one way or another. Is it a problem for motorcyclists?

Helmets MIGHT increase the risk of strangulation from overhanging bushes. Until this actually appears to be a problem, I'll not worry about it either.

(1) is quite simply incorrect. Helmets are TESTED at no more than 12 mph. They don't spontaneously vapourise at 15mph. I'd be interested to ask a helmet manufacturer what they do at 30 mph, for example. Its probably not great, but better than nothing.

But lets think about why 12mph. The argument "cars and bikes travel fast than 12 mph, so helmets are useless" is tempting. If you hit a hard object head on at high speed, you are probably right.

But what if you hit a windscreen? What about the fact that your neck is not rigid? What if you hit something at an angle?

What happens if you fall off and hit your head on the ground? If you are travelling at 20mph, the relevant speed is 20 mph, right? No. It depends on the component of your velocity perpendicular to the object you hit. For example, if the velocity is at an angle of 30deg to the road, the effective speed of impact is about 10mph.

Its complex and the relevance of 12mph compared to the speed of cars or cyclists is simplistic beyond belief. You can only say that they will offer protection as tested (or designed, if you want) for some accidents, but not for others.

In my opinion, the number "12 mph" is leading you to conclude that they are useless for a rather higher proportion of impacts than is actually the case. I wonder if the reason helmets are tested at 12 mph is not because helmet manufacturers have colluded with legislators and made the tests equal to the strength of the helmets that they can make profitably, but that 12 mph is a speed which is somewhat relevant to a cycling accident.

always_tyred

alfablue wrote:

Peer review in medical journals is no guarantee of validity or trustworthiness, whilst they claim to reject papers with "serious scientific flaws" the process still allows many articles that have methodological or other problems. No reader should accept any findings without some critical appraisal of their own (as you have done AT). Although articles may have flaws they can make a contribution to debate and the body of knowledge. The last journal I published in included a comment by one of the reviewers at the end (which shocked me a bit!) but it assists the reader in making a more informed appraisal for themselves. Unfortunately, those with vested interests, axes to grind, etc. can pluck favourable findings from these articles and build their own fallacious arguements, and as suggested above, the less aware readers on the internet will convert these in to "facts" for their own arguments, often compounding the flaws and misrepresentations from the original sources without critique. Caveat emptor and all that!

This annoys me. If its not robust, it should not be published. If its so questionable as to require that the reviewers coomments be published, or if a layman like me can rip it apart, it should not be published. It is an abdication of responsibility by the BMJ to publish what are essentially informed musings.

Clever Pun

AT the 12mph thing was used in the court case mentioned above in that if the impact to the head was over 12mph the compensation would have been paid out regardless of the cyclist wearing a helmet... in the eyes of the law.

Regardless o the dampening of the smack to your head wearing a helmet wont really make much difference in compensation terms... That's how I see it.

even if you're at a standstill and fall sideways onto your head, it's likely that the speed of your head will be greater than 12mph?

always_tyred

Clever Pun wrote:

AT the 12mph thing was used in the court case mentioned above in that if the impact to the head was over 12mph the compensation would have been paid out regardless of the cyclist wearing a helmet... in the eyes of the law.

Regardless o the dampening of the smack to your head wearing a helmet wont really make much difference in compensation terms... That's how I see it.

even if you're at a standstill and fall sideways onto your head, it's likely that the speed of your head will be greater than 12mph?

That's not what the judge said. He said this would be the case if it could be proved that a helmet WOULD have reduced the injury. He pointed out that the driver's side had provided no evidence when running the argument, and dismissed it. "Would" is a fairly high threshold, I think, but we will only know as and when the argument is successfully made.

CP, you do not appreciate the distinction between speed and velocity.

I'm not sure what 9.8ms-2 equates to in mph from approx 2m.

EDIT - I calculated, I think, that 12 mph is the velocity of an object falling under the influence of gravity from about 1.5m. What do you know - I reckon this is roughly the distance between the floor and your head when cycling. Perhaps not such an arbitrary number after all....

alfablue

Always Tyred wrote:

alfablue wrote:

Peer review in medical journals is no guarantee of validity or trustworthiness, whilst they claim to reject papers with "serious scientific flaws" the process still allows many articles that have methodological or other problems. No reader should accept any findings without some critical appraisal of their own (as you have done AT). Although articles may have flaws they can make a contribution to debate and the body of knowledge. The last journal I published in included a comment by one of the reviewers at the end (which shocked me a bit!) but it assists the reader in making a more informed appraisal for themselves. Unfortunately, those with vested interests, axes to grind, etc. can pluck favourable findings from these articles and build their own fallacious arguements, and as suggested above, the less aware readers on the internet will convert these in to "facts" for their own arguments, often compounding the flaws and misrepresentations from the original sources without critique. Caveat emptor and all that!

This annoys me. If its not robust, it should not be published. If its so questionable as to require that the reviewers coomments be published, or if a layman like me can rip it apart, it should not be published. It is an abdication of responsibility by the BMJ to publish what are essentially informed musings.

Well, to put the record straight, in my own case, that particular journal did so as a rule for all articles (there was no major flaw with mine!). These are professional or academic journals, and are not really aimed at a lay readership, and it is expected that the readership are sufficiently knowledgeable to do their own appraisal. Many studies with some flaws will also have much of merit, for example a study may have an insufficient sample size, but the data collection methods may be valid and could provide the basis for larger studies. The readership need to see flawed and inconclusive studies as much as the others, it is as important to learn what doesn't work as what does. And in any event there can never be a perfect study, nor proof of anything, it is just about developing the body of knowledge and determining what the best evidence suggests at a given time, whilst always being aware of the possibility that there could be a major shift or even reversal of that best evidence.

conceptsails

Am I missing something here? Can anyone give me a better reason for not wearing a helmet other 'than I don’t like it' or 'I have never had a crash and ride on quiet roads' I have been riding always with a helmet on for 25 years and never had a serious crash until this year when a car ploughed me down. I was riding along a quiet road that I have ridden almost every day for 5 years.
I am no expert but I think the chances of being hit by a car from behind that you don’t see are higher than being hung from a tree that doesn’t sneak up on you when your back is turned. (Has this ever actually happened?)
Speaking from experience - compensation claims has nothing to do with it, it’s about minimising risk so you can ride more and have broken skulls less.
It’s simple if you wear a helmet you have less chance of smashing your head in than if you do. But of course if you don’t want to mess up your hair or need somewhere to store your sunglasses then don’t wear one!
:evil: :evil:

greg66_tri_v2.0

This is quite an interesting read.

Mr. Jenkins weighs the empirical evidence he sees. Dr Hillman (seems to) base his view on assumptions. Who'd you choose to believe?

And... Dr H propounds the argument that wearing a helmet -> greater risk taking, but his examples (the wasp under the car seat belt; the spike on the steering wheel) are basically danger -> less risk taking, not perception of less danger -> greater risk taking.

Dr H no doubt doesn't practise what he preaches. After all, if he really wanted to ride carefully, he'd put a blindfold on and cut his brake cables first.

always_tyred

alfablue wrote:

Always Tyred wrote:

alfablue wrote:

Peer review in medical journals is no guarantee of validity or trustworthiness, whilst they claim to reject papers with "serious scientific flaws" the process still allows many articles that have methodological or other problems. No reader should accept any findings without some critical appraisal of their own (as you have done AT). Although articles may have flaws they can make a contribution to debate and the body of knowledge. The last journal I published in included a comment by one of the reviewers at the end (which shocked me a bit!) but it assists the reader in making a more informed appraisal for themselves. Unfortunately, those with vested interests, axes to grind, etc. can pluck favourable findings from these articles and build their own fallacious arguements, and as suggested above, the less aware readers on the internet will convert these in to "facts" for their own arguments, often compounding the flaws and misrepresentations from the original sources without critique. Caveat emptor and all that!

This annoys me. If its not robust, it should not be published. If its so questionable as to require that the reviewers coomments be published, or if a layman like me can rip it apart, it should not be published. It is an abdication of responsibility by the BMJ to publish what are essentially informed musings.

Well, to put the record straight, in my own case, that particular journal did so as a rule for all articles (there was no major flaw with mine!). These are professional or academic journals, and are not really aimed at a lay readership, and it is expected that the readership are sufficiently knowledgeable to do their own appraisal. Many studies with some flaws will also have much of merit, for example a study may have an insufficient sample size, but the data collection methods may be valid and could provide the basis for larger studies. The readership need to see flawed and inconclusive studies as much as the others, it is as important to learn what doesn't work as what does. And in any event there can never be a perfect study, nor proof of anything, it is just about developing the body of knowledge and determining what the best evidence suggests at a given time, whilst always being aware of the possibility that there could be a major shift or even reversal of that best evidence.

Totally, but in the journals I had to submit to, if your research was incomplete or flawed and the reviewers had spotted it, you either didn't get it published at all, or you had to state what the flaws were and what you could or could not say on the basis of the results. You could NOT claim the earth on the basis of flimsy evidence and trust that the readership (which was not in the least a lay readership) would spot the deliberate mistakes.
Didn't mean to impugne your article, btw.

alfablue

The BMJ article is in "the quality of life" section, rather than the research section, so may have only had editorial review, and in any case is a more appropriate section for such musings.

jimmypippa

Always Tyred:

I make 12mph to be 5.3m/s (say 5m/s) and g to be 10m/s/s

This equates to freefall for just over half a second

Which makes a height of about 1.25m

Anyway, if one's head did freefall from 2m you would have no more problems, ever, as it would be disconnected from your body.

To do the sum properly, you would want to look at moments of inertia (wiki) which would reduce the impact velocity. The centre of gravity of a person and bike is below the head.

always_tyred

alfablue wrote:

The BMJ article is in "the quality of life" section, rather than the research section, so may have only had editorial review, and in any case is a more appropriate section for such musings.

I think it should have been printed in the Sunday Mail. Or Reader's Digest.

always_tyred

jimmypippa wrote:

Always Tyred:

I make 12mph to be 5.3m/s (say 5m/s) and g to be 10m/s/s

This equates to freefall for just over half a second

Which makes a height of about 1.25m

Anyway, if one's head did freefall from 2m you would have no more problems, ever, as it would be disconnected from your body.

To do the sum properly, you would want to look at moments of inertia (wiki) which would reduce the impact velocity. The centre of gravity of a person and bike is below the head.

I got v^2=u^2 +2as, where U = initial vel = 0, a=9.8, s=1.5, meaning v=sqrt(29.4)=5.4m/s
5.4m/s=19.4km/h=12mph, give or take.
Anyone still awake?

laughingboy

Always Tyred wrote:

I got v^2=u^2 +2as, where U = initial vel = 0, a=9.8, s=1.5, meaning v=sqrt(29.4)=5.4m/s
5.4m/s=19.4km/h=12mph, give or take.
Anyone still awake?

It's proof that your brain needs protecting, you clever man, you.

I understand why you take exception to the article's appearance in the BMJ (it being a scientific journal, and not, say, the side of a bus), but one of the arguments made in the article seems valid to me:

"7 The health benefits of cycling are so great---and the health injuries from driving so great8---that not cycling is really dangerous. By telling people that they need helmets for an activity that for a century has been regarded as "safe"---and in fact has a fine safety record---you inevitably engender the impression that cycling must have become more dangerous than driving and walking. That deters cycling. That reduces cyclists' presence on the roads. That increases the risk of death."

As for me, I wear a helmet, but I would defend anyone's choice not to, whether for reasons of comfort, convenience, style, or even simple ignorance of the studies made into their effectiveness.

Helmets are probably a disproportionate response to a risk. I do not think that they are necessary, and I would resist any law making them obligatory.

always_tyred

laughingboy wrote:

Always Tyred wrote:

I got v^2=u^2 +2as, where U = initial vel = 0, a=9.8, s=1.5, meaning v=sqrt(29.4)=5.4m/s
5.4m/s=19.4km/h=12mph, give or take.
Anyone still awake?

It's proof that your brain needs protecting, you clever man, you.

I understand why you take exception to the article's appearance in the BMJ (it being a scientific journal, and not, say, the side of a bus), but one of the arguments made in the article seems valid to me:

"7 The health benefits of cycling are so great---and the health injuries from driving so great8---that not cycling is really dangerous. By telling people that they need helmets for an activity that for a century has been regarded as "safe"---and in fact has a fine safety record---you inevitably engender the impression that cycling must have become more dangerous than driving and walking. That deters cycling. That reduces cyclists' presence on the roads. That increases the risk of death."

As for me, I wear a helmet, but I would defend anyone's choice not to, whether for reasons of comfort, convenience, style, or even simple ignorance of the studies made into their effectiveness.

Helmets are probably a disproportionate response to a risk. I do not think that they are necessary, and I would resist any law making them obligatory.

Yes, but there are significant conclusions following from conclusions that have not got any citations, you will note. I've not actually seen anything to convince me that helmets make people think cycling is more dangerous than they otherwise would. Seeing a bicycle in close company with motor vehicles on increasingly crowded roads surely engenders an intuitive response that it looks dangerous, regardless of what they are wearing. So where does the supposition that helmets make it look more dangerous actually come from? From what I've seen, it is the result of a few vox pops where people answer ever so slightly leading questions such as "Do cycle helmets make you think cycling is dangerous?" Opinion data, they call it.

And the first 100 years thing is trite. People used to drive open topped racing cars with a pair of goggles and a scarf, sat in a seat shaped part of the fuel tank. Kids used to play with mercury in school. Times change. Crikey, we even do situps differently.

I don't think helmets should be mandatory either, not that I'd particularly, mind, but I do wish the decisions people make were sufficiently informed. For example, it strikes me that a lot of people just can't imagine that expanded polystyene is any use and, for one reason or another, conclude thathelments are crap, so why bother wearing them.

I've previously asked the question, "would you wear a helmet if you thought it offered a good level of protection?" and at least one person said yes. Given that the 12mph test is the most often cited reason that they must be useless, I thought I'd try a little maths to demostrate that it isn't so clear cut. Where are all the engineers when you need them?

Clever Pun

Always Tyred wrote:

Clever Pun wrote:

AT the 12mph thing was used in the court case mentioned above in that if the impact to the head was over 12mph the compensation would have been paid out regardless of the cyclist wearing a helmet... in the eyes of the law.

Regardless o the dampening of the smack to your head wearing a helmet wont really make much difference in compensation terms... That's how I see it.

even if you're at a standstill and fall sideways onto your head, it's likely that the speed of your head will be greater than 12mph?

That's not what the judge said. He said this would be the case if it could be proved that a helmet WOULD have reduced the injury. He pointed out that the driver's side had provided no evidence when running the argument, and dismissed it. "Would" is a fairly high threshold, I think, but we will only know as and when the argument is successfully made.

CP, you do not appreciate the distinction between speed and velocity.

eh??
speed and velocity are used to describe the same thing surely, the movement of an object??? unless you're talking about drugs

http://dictionary.reference.com/browse/velocity

gb155

Well I purchased one today, Im part of the dark side now, Not that I have worn it yet though, Thats another story.

always_tyred

Clever Pun wrote:

eh??
speed and velocity are used to describe the same thing surely, the movement of an object??? unless you're talking about drugs

http://dictionary.reference.com/browse/velocity

Velocity is a vector property, speed simply the magnitude of velocity.

i.e. By taking the M8 from Edinburgh, I can head of to Glasgow at 70mph, or take the M9 turn to Stirling at 70mph. I will have the same speed in each case, but a different velocity. If my velocity is 70mph to Stirling, the force of impact of my vehicle with the back of the queue at J12 of the M8 will be zero, whereas if my velocity is 70mph to Glasgow, it will kill me.

laughingboy

Always Tyred wrote:

laughingboy wrote:

"7 The health benefits of cycling are so great---and the health injuries from driving so great8---that not cycling is really dangerous. By telling people that they need helmets for an activity that for a century has been regarded as "safe"---and in fact has a fine safety record---you inevitably engender the impression that cycling must have become more dangerous than driving and walking. That deters cycling. That reduces cyclists' presence on the roads. That increases the risk of death."

Yes, but there are significant conclusions following from conclusions that have not got any citations, you will note. I've not actually seen anything to convince me that helmets make people think cycling is more dangerous than they otherwise would. Seeing a bicycle in close company with motor vehicles on increasingly crowded roads surely engenders an intuitive response that it looks dangerous, regardless of what they are wearing. So where does the supposition that helmets make it look more dangerous actually come from? From what I've seen, it is the result of a few vox pops where people answer ever so slightly leading questions such as "Do cycle helmets make you think cycling is dangerous?" Opinion data, they call it.

And the first 100 years thing is trite. People used to drive open topped racing cars with a pair of goggles and a scarf, sat in a seat shaped part of the fuel tank. Kids used to play with mercury in school. Times change. Crikey, we even do situps differently.

I don't think helmets should be mandatory either, not that I'd particularly, mind, but I do wish the decisions people make were sufficiently informed. For example, it strikes me that a lot of people just can't imagine that expanded polystyene is any use and, for one reason or another, conclude thathelments are crap, so why bother wearing them.

I've previously asked the question, "would you wear a helmet if you thought it offered a good level of protection?" and at least one person said yes. Given that the 12mph test is the most often cited reason that they must be useless, I thought I'd try a little maths to demostrate that it isn't so clear cut. Where are all the engineers when you need them?

The British engineers are all in their 19 century graves, I fear.

Anyway, the idea that wearing a helmet contributes to the perception of dangers of cycling is probably not provable by scientific means, but it makes perfect sense to me. The human brain is not very rational, and makes unconscious judgments based on any evidence, no matter how limited. So, if we see someone dressed in protective gear, then we put two and two together and think: dangerous.

Similarly, to use an analogy, when I see TV pictures of the smog in the Far East, I think: nasty smog! Then when I see pictures of people there walking around in medical masks, it makes me think that the smog must pose an immediate danger to those people's health. I make this judgement on very little evidence, and yet I know - if I ever use the rational part of my brain - that it may not be the correct conclusion. Yet, I still have the feeling that it the air is not safe.

That, I think is a valid - if unscientific - argument against helmets. By their oddness, they must create an irrational response, and people can't help overstating the dangers of cycling accordingly.

I hope my analogy is not too strained.

always_tyred

Fair enough, so long as you concede that its not entirely rational. Oh, you just have.

jimmypippa

Always Tyred wrote:

I got v^2=u^2 +2as, where U = initial vel = 0, a=9.8, s=1.5, meaning v=sqrt(29.4)=5.4m/s
5.4m/s=19.4km/h=12mph, give or take.
Anyone still awake?

Oh, yes AT, your sum is correct, the differences are just rounding errors, on my part, because I (being an engineer of little brian) like numbers where I can do the sums in my head, and I can still multiply one quarter by five.

As I said earlier, if you toppled sideways to the ground from a head-height of 1.5m, your head would hit the ground slower than if it had been decapitated and fell the 1.5metres.

If we ignore that for a moment, and consider a crash, then quite often people are breaking, and have slowed down a lot at the moment of impact. Then you add the possibility of arms taking some of the impact, and the effective speed where helmets mean the differnce between serious head injury, and minor head injury increases.

I agree with you about speed and velocity. As I use difffernt language, I'll try to reiterate it.

I might be an engineer by inclination and profession, but I am a physicist by training, so I like idealised systems that are unreal:

If you come off your bike at 30mph onto a smooth surface that slopes down as you land, then it is possible that your head's velocity perpendicular to the surface is very small. The velocity parallel to the surface will be about 30mph. You would get a nasty road-rash, but your head should bo OK... Until there is a kerbstone, where your head has a relative velocity of 30mph towards that kerbstone. If the kerbstone is at 30° to the direction of travel, then the velocity perpendicular to the kerbstone's surface will be halved, and the impact becomes equivalent to a 15mph impact. (30mph times sine 30°)

This is why *I* wear a helmet.

An article arguing against compulsory helmet-wearing on the grounds that this increases the perceived danger of cycling thus reduceing the amount of cycling, makes no difference as to whether one *should* wear a helmet. If backed up by figures, it might make a difference to the whole public-health debate, but not to individuals decisions.

The_Darkness

WGWarburton wrote:

Always Tyred writes:

> Haven't you just applied all of the same assumptions, in your own sweet way?

Of course, but the key difference is that mine are correct and The_Darkness' are wrong! :-)

More specifically- you can look at the accident statistics and determine that cycling isn't particularly dangerous (hundreds of thousands of miles between KSIs, IIRC), at the experience of countries where helmets have been mandated (no significant drop in head injuries) and assess from there.
I don't have a problem with people wearing helmets, if they want to do so, what grates on me is the assumption that they are needed, that they are effective and that others are somehow shirking their reponsibilities by choosing not to.
Maybe if The Darkness would care to justify his starting point, I'd be less irritated. I might still think s/he's wrong, but at least we'd get away from the dubious assumption that it doesn't even need to be stated.

Cheers,
W.

My remark was simply meant as a counter-statement to the folks who seemed to think that because you have a right (or not) to do something, then its 'ok' to do so.

I have more important things to consider than my rights as an individual, thats all.

The use of the word 'significant' when considering head injuries would appear to be justification enough. But then I havent fully researched the statistics, so my opinion is simply based on unfashionable (these days) common sense.

If I fall of my bike would I prefer to a) be wearing a helmet of b) not wearing a helmet.

Its pretty hard to argue b).

Cheers

Cunobelin

The 12 mph is the design and performance limit for helmets....

The question is if you had a car whose brakes were only designed and tested to 12 mph would you drive at 30 - 40 mph because "any braking is better than none"

The point is that if we are serious about helmets we should be getting rid of EN1078 and testing more in lines with SNELL ... Off the shelf sampling - higher impacts, better reproduction of real conditions.

We should be looking at getting rid of all the helmets that are designed and manufactured to standards that do not deal with real life situations.

steve-m

The_Darkness wrote:

If I fall of my bike would I prefer to a) be wearing a helmet of b) not wearing a helmet.

Its pretty hard to argue b).

Cheers

Such is the nature of reducing a complex argument down to a binary question.

So would you rather

a) come off your bike
b) not come off your bike
c) not cycle

Regardless of whether you are wearing a helmet.

In this country it has reached the point where non-cyclists think those wearing helmets as irresponsible, we have a screaming media that loves to slag off cyclists making it an ideal climate for a MHL. The is evidence that a MHL does decrease cycling and there is evidence that less cyclists makes it more dangerous for those that remain meaning a or c become more likely.

There is little evidence of helmets offering any protection, evidence that MHLs are a dangerous thing and a government intention that once helmet wearing becomes above a certain percent we will have a MHL[1] then it is clearly all too simplistic to talk about responsibility or binary choices

[1] Obviously this is the most outrageous part of the issue and I accept noone here has argued for an MHL; I equally support people's freedom to wear them - but please at least attempt to verify your reason for wearing one, most people wear them because of pressure from non-cyclists.