View Poll Results: Helmet wearing habits?
I've never worn a bike helmet
178
10.66%
I used to wear a helmet, but have stopped
94
5.63%
I've always worn a helmet
648
38.80%
I didn't wear a helmet, but now do
408
24.43%
I sometimes wear a helmet depending on the conditions
342
20.48%
Voters: 1670. You may not vote on this poll
The helmet thread
07-23-14, 09:47 AM
#8252
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Well, had a front tire wash out and went head first into a curb. Helmet saved me a concussion and saved my ear... didn't help much for my lip nose and teeth.
07-23-14, 10:02 AM
#8253
Senior Member
Yes and No, but overall this statement is unfair and misleading.
Like just about every product, from children's toys to aircraft, things are designed based both engineering (to ensure that it'll work and do what it's supposed to do) and cosmetic or other factors to appeal to the market. A product that works great but won't sell, or a beautiful product that doesn't do what it's supposed to are both useless.
Yes, over the last few years great effort has gone into fashion and marketability, but the helmets still must pass basic engineering standards and the various Snell or ANSI tests before they go into production.
Like just about every product, from children's toys to aircraft, things are designed based both engineering (to ensure that it'll work and do what it's supposed to do) and cosmetic or other factors to appeal to the market. A product that works great but won't sell, or a beautiful product that doesn't do what it's supposed to are both useless.
Yes, over the last few years great effort has gone into fashion and marketability, but the helmets still must pass basic engineering standards and the various Snell or ANSI tests before they go into production.
CPSC published rules and regs definition of a bicycle helmet, p. 11715:
the definition of bicycle helmet has been changed to read: ‘‘Bicycle helmet means any headgear that either is specifically marketed as, or implied through marketing or promotion to be, a device intended to provide protection from head injuries while riding a bicycle.’’
07-23-14, 10:15 AM
#8254
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Not unfair or misleading at all, I was actually being technical with my description. According to the government body which defines what constitutes a bicycle helmet, they are defined by how a manufacturer markets a helmet.
CPSC published rules and regs definition of a bicycle helmet, p. 11715:
CPSC published rules and regs definition of a bicycle helmet, p. 11715:
Yes, a bicycle helmet isn't one unless the seller says it is. That's just reversing the statement that someone can't sell a helmet that doesn't meet the standard. All government rules have some kind of similar statement to define the turf. In this case it ensures that Stetson can't be held to the helmet standard when they sell 10 gallon hats.
But I posted only because the way you made the statement in response to the quoted passage implied that fashion was trumping engineering in helmet design. If that wasn't the intent, consider my post as a minor technical correction and ignore it.
__________________
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Chain-L site
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
Last edited by FBinNY; 07-23-14 at 11:07 AM.
07-23-14, 11:04 AM
#8255
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I really could have used some shoulder pads when that happened to me a couple of years ago. Helmet wasn't much use in that one.
07-23-14, 11:07 AM
#8256
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Yes, a bicycle helmet isn't one unless the seller says it is. That's just reversing the statement that someone can't sell a helmet that doesn't meet the standard. All government rules have some kind of similar statement to define the turf. In this case it ensures that Stetson can't be held to the helmet standard when they sell 10 gallon hats.
But I posted because that way you made the statement, in response to the quoted passage implied that fashion was trumping engineering in helmet design. If that wasn't the intent, consider my post as a minor technical correction and ignore it.
But I posted because that way you made the statement, in response to the quoted passage implied that fashion was trumping engineering in helmet design. If that wasn't the intent, consider my post as a minor technical correction and ignore it.
That really is close to what the authors intended. They also examined the regulations and standards in some detail. Seriously it's a good read.
07-23-14, 12:40 PM
#8257
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07-23-14, 12:45 PM
#8258
cowboy, steel horse, etc
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Better than eating with a straw, as they say.
07-23-14, 06:47 PM
#8259
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Accidents are not a planned event, unless you are some kind of extreme rider. It sucks, but it happens. Hey, it was a great ride until then...
07-23-14, 06:57 PM
#8260
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Ha, I guess at 57 I'm still getting the face I deserve...
07-23-14, 09:06 PM
#8261
Senior Member
Yes, a bicycle helmet isn't one unless the seller says it is. That's just reversing the statement that someone can't sell a helmet that doesn't meet the standard. All government rules have some kind of similar statement to define the turf. In this case it ensures that Stetson can't be held to the helmet standard when they sell 10 gallon hats.
But I posted only because the way you made the statement in response to the quoted passage implied that fashion was trumping engineering in helmet design. If that wasn't the intent, consider my post as a minor technical correction and ignore it.
But I posted only because the way you made the statement in response to the quoted passage implied that fashion was trumping engineering in helmet design. If that wasn't the intent, consider my post as a minor technical correction and ignore it.
*respectful golf clap*
07-24-14, 10:03 AM
#8262
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wphamilton:
I suspect you meant to type 120 to 150 g ?
Joe
I suspect you meant to type 120 to 150 g ?
Joe
07-25-14, 07:05 AM
#8263
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curbtender
Your accident is the very kind of accident I claim can happen to anyone. The anti helmet posters here seem to claim their "great bike handling skills" will prevent something like that happening to them.
Some day they will find that their bare head makes a very poor brake pad.
Your accident is the very kind of accident I claim can happen to anyone. The anti helmet posters here seem to claim their "great bike handling skills" will prevent something like that happening to them.
Some day they will find that their bare head makes a very poor brake pad.
07-25-14, 02:28 PM
#8266
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No, strange as it may seem it takes 1200 to 1500 g. 120-150g would be typical for a skull fracture.
For a straight on blow, when the head isn't allowed to move to a side or rotate, it takes much more acceleration for the concussion. But with even an inch movement (instead of fixed) it becomes fatal.
Here is the quote:
In the BICYCLE HELMETS: A SCIENTIFIC EVALUATIONhttps://www.cyclehelmets.org/papers/p787.pdf "One experiment indicated that the critical acceleration to produce concussion was 1500 g. Unlike the experiments by previous investigators, where the head had always been fixed, in some of these it was allowed to move. This resulted in the interesting finding that a blow to a fixed head caused no concussion, though greater distortion of the skull should have occurred, but the same blow repeated with the head allowed to move 2.5 cm resulted in death. "
Rotation (or more precisely angular acceleration), even over a very short arc, is where we get in trouble. As far as severe concussions go.
So what does that mean with respect to the bicycle helmet safety standards? There is a lot of data but not that many rigorous conclusions. Even in the linked evaluation it's noted, "As regards correlation of linear acceleration and degree of cerebral concussion produced, Gurdjian et al. subjected dogs to hammer blows to the head [38]. The results ranged from severe concussion at linear acceleration of less than 100g to none at more than 700g. The authors concluded that no correlation was shown. "
So on one hand we've got 1500g for critical acceleration, and another showing no correlation with acceleration, and standards that assume that linear acceleration is the main factor. What it DOES mean is that for all that is factually known about traumatic brain injury and protection from, there is more unknown or, sometimes, disregarded. For our purposes, our foamy bike helmets are designed to protect against impulse from a direct impact, and little else. Specifically not angular acceleration.
As a matter of fact, there is reference to a test with monkeys in helmets (seems appro to the thread). Six wore helmets, and six wore helmets and cervical collars (limiting rotation). All of the helmet only suffered concussions. None of the collared suffered concussions.
We can go a step further into the almost-unknown. There were more tests about rotations caused by sliding, with the types of helmets we use, at about the speeds we ride. Soft-shell, Styrofoam helmets. Unlike hard-shell helmets, they tended to grab the surface, rotating the head at four to six times the tolerable maximum. Ventilation holes make it worse. Even more disturbing, the added mass of the helmets increase the rotation of a glancing blow.
So people think I'm insane for wanting to reduce the surface area of a helmet, and reduce the mass and cut the lines so that angular deflection is not as likely. Maybe I have a logical reason after all ...
For a straight on blow, when the head isn't allowed to move to a side or rotate, it takes much more acceleration for the concussion. But with even an inch movement (instead of fixed) it becomes fatal.
Here is the quote:
In the BICYCLE HELMETS: A SCIENTIFIC EVALUATIONhttps://www.cyclehelmets.org/papers/p787.pdf "One experiment indicated that the critical acceleration to produce concussion was 1500 g. Unlike the experiments by previous investigators, where the head had always been fixed, in some of these it was allowed to move. This resulted in the interesting finding that a blow to a fixed head caused no concussion, though greater distortion of the skull should have occurred, but the same blow repeated with the head allowed to move 2.5 cm resulted in death. "
Rotation (or more precisely angular acceleration), even over a very short arc, is where we get in trouble. As far as severe concussions go.
So what does that mean with respect to the bicycle helmet safety standards? There is a lot of data but not that many rigorous conclusions. Even in the linked evaluation it's noted, "As regards correlation of linear acceleration and degree of cerebral concussion produced, Gurdjian et al. subjected dogs to hammer blows to the head [38]. The results ranged from severe concussion at linear acceleration of less than 100g to none at more than 700g. The authors concluded that no correlation was shown. "
So on one hand we've got 1500g for critical acceleration, and another showing no correlation with acceleration, and standards that assume that linear acceleration is the main factor. What it DOES mean is that for all that is factually known about traumatic brain injury and protection from, there is more unknown or, sometimes, disregarded. For our purposes, our foamy bike helmets are designed to protect against impulse from a direct impact, and little else. Specifically not angular acceleration.
As a matter of fact, there is reference to a test with monkeys in helmets (seems appro to the thread). Six wore helmets, and six wore helmets and cervical collars (limiting rotation). All of the helmet only suffered concussions. None of the collared suffered concussions.
We can go a step further into the almost-unknown. There were more tests about rotations caused by sliding, with the types of helmets we use, at about the speeds we ride. Soft-shell, Styrofoam helmets. Unlike hard-shell helmets, they tended to grab the surface, rotating the head at four to six times the tolerable maximum. Ventilation holes make it worse. Even more disturbing, the added mass of the helmets increase the rotation of a glancing blow.
So people think I'm insane for wanting to reduce the surface area of a helmet, and reduce the mass and cut the lines so that angular deflection is not as likely. Maybe I have a logical reason after all ...
07-25-14, 02:32 PM
#8267
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Later research supports the findings of Corner et al. on the effects of helmets on rotation.In 1991, Hodgson reported tests of hard shell, micro-shell and no-shell helmets in skid-type impacts on concrete inclined at angles from 300 to 600, from a speed around 12 km/h [50]. The hard and micro-shell helmets tended to slide, but the concrete surface penetrated and hung onto the nylon cover and liner of the no-shell helmets, forcing the neck into flexion.
07-25-14, 04:31 PM
#8268
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Hope you all make the right choice for your riding. I'm paying for something I've made a lifestyle. Hey," ain't dead, ain't in jail" as quoted from a friend that can't claim that any more...
07-26-14, 09:24 AM
#8272
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curbtender
Your accident is the very kind of accident I claim can happen to anyone. The anti helmet posters here seem to claim their "great bike handling skills" will prevent something like that happening to them.
Some day they will find that their bare head makes a very poor brake pad.
Your accident is the very kind of accident I claim can happen to anyone. The anti helmet posters here seem to claim their "great bike handling skills" will prevent something like that happening to them.
Some day they will find that their bare head makes a very poor brake pad.
but untill you reach that level, youre gonna have to dismount
07-26-14, 10:29 AM
#8273
Senior Member
The bike helmet serves poorly for that as well.
pge 156 https://www.cyclehelmets.org/papers/p787.pdf
pge 156 https://www.cyclehelmets.org/papers/p787.pdf
07-26-14, 04:37 PM
#8274
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Junior Heffernan and many other pro racers who all died being hit by cars, trucks, and motorcycles just don't have as good of skills as you have. Thank you for blessing us with your superior and god like abilities on a bike.
07-26-14, 05:19 PM
#8275
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I guess Felix Baur, Burry Stander, Carla Swart, Frank Guinn, Peter Gunther, Adrian Buttafocchi,
Junior Heffernan and many other pro racers who all died being hit by cars, trucks, and motorcycles just don't have as good of skills as you have. Thank you for blessing us with your superior and god like abilities on a bike.
For which a helmet in all likelihood would have not helped. It is a helmet thread after all.
