The CycleChat Helmet Debate Thread

[Mugshot]

And strangely enough they are the very same people complaining about amateur fair-weather cyclists daring to impede their progress at this time of year.

Some people are twats.

 

[srw]

That is one quality Sig line on offer.

Did you have a particular Sig in mind?

 

[mjr]

So why have I started wearing one? answer the wife insists even after I have pointed out pros & cons

Why does your wife want you to crash more often?

More seriously, I don't understand how any adult can claim to love another but insist on micromanaging them. For example, I'd prefer that my wife didn't wear a helmet, but she usually does (not always), she knows my views on the subject (and I know hers) and I just have to leave it at that. There are some actions (or inactions) which might end things but this is far far from being one.

 

[ufkacbln]

I I ride the Dutchie in my current avatar, mostly sitting fairly upright with the bar ends where my hands would rest on a desk and often using cycle tracks.

I remember John Peel promoting undertaking by promoting this song with its unacceptable road safety message..... undertaking is unacceptable

 

[Venod]

More seriously, I don't understand how any adult can claim to love another but insist on micromanaging them.

Its very unlike me to go against what I think is my better judgement, I think she was shocked when I agreed to wear one all the time, do I subconciously think its a good idea ? I think the accident shook me up more than I am admitting, it was almost head on, if the car had it me head on I would have have probably hit the windscreen, helmet or no helmet would my head have survived the impact, who knows, but I think the accident has changed my attitude a little.

 

[Justinslow]

"No. Person A was indoors minding their own business and fell - pure accident. Person B was on a road surrounded by muppets in 2 ton steel boxes and was pushed - an accident, but a foreseeable risk."



It's relevant becasue the probability of falling is increased out on the road while in a position of 'readiness to plummet' which is what stretching forward is. The indoor example is of a person who is vertical and not in traffic. Bloomin eck, obtuse isn't the word.


Yes, two identical injuries, assuming that: the motor scooters weight 2 tons, have poor visibility in blind spots, are travelling at 40 mph and the person in the example is poised at a rakish angle where once they fall they have little chance of righting themselves (as is the case on a bicycle) FFS.
Yes, it is logical becasue one is unlikely and the other is encountered by me every day.

OK, I give in. Reading in a library is unsafe and smoking is not a cause of lung cancer, just look at my uncle nob head, he smoked all his life then got knocked off his bike by a speeding granny on a scooter. Nowt to do with the fags mate.

It's great here isn't it?

 

[Mugshot]

It's great here isn't it?

You could make it greater if you like, maybe start by answering @benb s question post 3021, the poor bugger asked it ages ago and he's been roundly ignored.

 

[martint235]

I have never been anti helmet, sometimes I wore one (had to on club runs and competing) but if out on my own I never wore one, all change since I had an accident, broken shoulder badly damaged leg, but no head injuries, the only person who asked "were's your helmet" was a police woman, I was on my back in agony at the time, I think I must have have given her a what a tosser look as she immediatly said but you have no head injuries so it wouldn't have made a difference.

So why have I started wearing one? answer the wife insists even after I have pointed out pros & cons, so I am now £80 lighter after forking out for a Specialized Prevail I have always used cheaper slightly heavier helmets, but if I have to wear one all summer I want light & a good airflow, it doesn't feel any more comfortable than the cheap ones, but might be after a long hot day.

This is one argument I understand. You know it's of little use, you're under no illusion about the supposed benefit of wearing a helmet but you choose to do so to keep your wife happy.

I've had the conversation with SWMBO and, for the time being, won but there are times when it's just best to give in. The next time I crash I might lose the argument. The thing is her nuclear option is no cycling at all and I won't provoke that.

Now there's probably a study somewhere that shows a happy wife = a happy man.

 

[Wobblers]

***I am not pro-compulsory helmet wearing**
** I agree that anecdotal evidence is flimsy evidence**
**I am not an expert and simply would like to learn more**

Sorry, got distracted with work. I looked at a rider falling 2 m onto a solid floor (the speed of the rider is immaterial unless you are also considering rotational frictional forces, which our could easily do too, but I'll ignore for now...) and took the deformation of the helmet foam to be 10 mm (of ~20 mm on my helmet). Now whether this actually hgappens or not is important and I would like to see an experimental measurement - any data on that?? So, my very simple calculations were fore deceleration of a 5 Kg head through 10 mm after free fall from 2 m in the air (e.g. knocked off bike and free fall to solid ground). The deceleration is about 180 g which is below the <250 g I understand that the makers have to claim to get EU approval (?).
If on the other hand you assume that an unprotected head hits the ground and deflects by 3 mm (broken skin and some skull deformation) then the deceleration is about 600 g (i.e. 3.3. times more).
Obviously the internal reaction of all that fluid and blobby brain is going to influence this too, but that is extremely complex to model and doesn't take away the fact that the impact energy is reduced when wearing a helmet.
I presume someone out there has decided that < 250 g gives a fighting chance of reducing injury. Anyone know?

100g acceleration is sufficient to cause fatal head injuries. Therefore in your example helmet wearing still results in death. This still holds even if you assume an extreme 90% helmet compression. Actually, it may be worse than that.as a helmet increases the cross sectional area of the head by about 40% - implying that the probability of a fatal impact load is increased by helmet wearing. This, of course, is before we consider rotational loading... or that helmet straps allow for the efficient transfer of impact loads to some very vulnerable cervical and basal skull structures...

ETA: The initial velocity of the rider is most definitely significant: overall deceleration is a vector sum of both lateral and vertical deleceration. At 12 mph, overall deceleration can be as mch as 40% higher than what you've calculated.

 

[ufkacbln]

OK, I give in. Reading in a library is unsafe and smoking is not a cause of lung cancer, just look at my uncle nob head, he smoked all his life then got knocked off his bike by a speeding granny on a scooter. Nowt to do with the fags mate.

This is a brilliant example - thank you


You have decided that because the cause of injury was an errant OAP on a scooter that the other factors are irrelevant and not harmful.

Your logic has decreed that libraries are unsafe , and that cigarettes are safe, in direct contravention of the actual reality

This is exactly the same as perceiving that cyclists have head injuries because of traffic, and that outside the traffic environment head injuries do not occur

 

[MontyVeda]

You could make it greater if you like, maybe start by answering @benb s question post 3021, the poor bugger asked it ages ago and he's been roundly ignored.

Many have asked the same question... best answer i got was 'because it's a cycling forum and we're talking about cycling related injuries' .... which to me is the same as sticking ones fingers in their ears and going 'la la la' very loudly.

 

[Mugshot]

Many have asked the same question... best answer i got was 'because it's a cycling forum and we're talking about cycling related injuries' .... which to me is the same as sticking ones fingers in their ears and going 'la la la' very loudly.

Yeah, the best is a bit crap really isn't it.

 

[philepo]

100g acceleration is sufficient to cause fatal head injuries.

How do you know?
Therefore in your example helmet wearing still results in death. This still holds even if you assume an extreme 90% helmet compression. No, it would be close to 100 g Actually, it may be worse than that.as a helmet increases the cross sectional area of the head by about 40% actually average radius is most important factor and that helmet increases it by about 28% - implying that the probability of a fatal impact load is increased by helmet wearing. Agreed, but the probability increase will be tiny This, of course, is before we consider rotational loading... Yes, very important point or that helmet straps allow for the efficient transfer of impact loads to some very vulnerable cervical and basal skull structures...

ETA: The initial velocity of the rider is most definitely significant: overall deceleration is a vector sum of both lateral and vertical deleceration. At 12 mph, overall deceleration can be as mch as 40% higher than what you've calculated.[/QUOTE]
That is 12 mph head on, like a bash to a car. I calculated it from a fall from a height to pavement, ie like being knocked off the bike and free falling to ground

This is a brilliant example - thank you

You have decided that because the cause of injury was an errant OAP on a scooter that the other factors are irrelevant and not harmful. No, it was joke

Your logic has decreed that libraries are unsafe , and that cigarettes are safe, in direct contravention of the actual reality

This is exactly the same as perceiving that cyclists have head injuries because of traffic, and that outside the traffic environment head injuries do not occur

No, it was joke

Many have asked the same question... best answer i got was 'because it's a cycling forum and we're talking about cycling related injuries' .... which to me is the same as sticking ones fingers in their ears and going 'la la la' very loudly.

If you link it I'll answer it. Thanks.

I have not said that a helmet will save you. I have said that if you end up free falling to ground and bang your head on the ground, then having 10 mm of constant deceleration (from helmet) rather than (an estimated by me) 3 mm of bone/skin deflection, the colossal g is reduced to just high g and that is a good thing. I also think that in traffic the risk of falling is increased by other peoples actions. It may be the case that rotational injuries are exasperated by the helmet but I am not sure. I am not pro helmet just anti poor anti arguments.

 

[Mugshot]

If you link it I'll answer it. Thanks.

Good.

More people suffer head injuries as pedestrians than as cyclists. If you are proposing a public health intervention, then you will always look at absolute risk rather than relative, so even if cycling is relatively more risky than walking, pedestrian helmets (assuming you are correct that they are effective) would save a lot more injuries if they were worn by pedestrians than by cyclists. yet you are suggesting only cyclists ought to wear them. Why?

Why are you only attempting to protect cyclists?

It's not me being obtuse: you need to demonstrate why it's worth protecting one group from head injury but not another. The fact that you cannot, and resort to straw man arguments is illuminating.

 

[MontyVeda]

...
If you link it I'll answer it. Thanks.

...

the question in this post... Why are you only attempting to protect cyclists?