|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
Wear a helmet, you know it makes sense
On Sun, 24 Feb 2019 12:59:26 +0000, RJH wrote:
Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. What if wearing a helmet makes things worse in certain circumstances? How do you determine that the circumstances that it makes worse are less prevalent or less serious than the ones where it helps? Suppose I had some sort of lucky talisman that would protect you from all injury if you ever fell off your bike with no other vehicle around, but it made it twice as likely that you'd be hit by each car that overtook you. Would you want one of your own? Your logic (i.e. that it helps in certain circumstances, so must be good) suggests you'd want the talisman, even though it nearly doubles the chances of your death each time you go out riding (cyclists rarely die without interaction with a motor vehicle). Cycle helmets are designed to help in the sort of impacts that arise from falling off. They aren't designed to achieve very much in a motor vehicle impact. That's why they have disclaimers on them saying they aren't suitable for motor sport. regards, Ian SMith -- |\ /| no .sig |o o| |/ \| |
Ads |
#12
|
|||
|
|||
Wear a helmet, you know it makes sense
On Sun, 24 Feb 2019 12:59:26 +0000
RJH wrote: Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. But what about the circumstances when a helmet can be harmful? Rotational brain trauma can be more damaging than direct impact, for example. And did you know that you might be more likely to be hit by a car if you're wearing a helmet? Bicycle helmets are designed to protect from impact in rather specific circumstances which roughly equate to toppling over at low speed and hitting your head on the kerb. Beyond that there's no guarantee that a helmet will provide any protection at all. Now in all my years of cycling (some while wearing a helmet) I've never encountered those specific circumstances. I've fallen off in a variety of ways, some of them fairly high-energy resulting in broken bones, but I've never thought a helmet saved my brain, or would have if I'd been wearing one. It's possible that a helmet might have helped the chap in the story, but that has to be one of the rare examples - sufficiently noteworthy that it got in the paper. |
#13
|
|||
|
|||
Wear a helmet, you know it makes sense
On 24/02/2019 11:55, GB wrote:
On 23/02/2019 19:27, Simon Jester wrote: On Saturday, February 23, 2019 at 12:49:54 AM UTC, MrCheerful wrote: https://www.theargus.co.uk/news/1745...afety-warning/ What evidence do you have to show a cycle helmet would have made any difference? Research shows cycle helmets can only absorb 70 joules before failing and it takes around 1000 joules to crack a human skull. How many joules does it take to cause a catastrophic bleed on the brain, though? I'm not sure what you mean by 'before failing'? Does that mean the helmet cannot absorb more than 70 joules altogether? Or it cracks but still absorbs some of the impact? The head has potential energy before a crash. If it freefalls to the ground, that will contribute to a vertical component of kinetic energy when it hits the ground. 5kg falling 1.8m has an original PE of 88J and hits the ground at 12.5mph. It should be noted that the head has the same potential energy when riding a bike as when walking so I don't understand why riding a bike is considered to need special treatment. In the DfT's "Reported Road Casualties Great Britain: 2016" it says: "The pattern for pedal cycles is an interesting one: the overall casualty rate of around 5,400 casualties per billion miles cycled is close to the motorcycling casualty rate, whereas the fatality rate of 29.5 per billion miles cycled is much closer to the pedestrian rate" The figure given for pedestrians is 34.5 fatalities per billion miles. Clearly a helmet has a tiny bandwidth - it can't do anything about the worst injuries (or, if it does, it would be clear evidence that pedestrians should use them) and it won't move the less severe off the chart. And clearly helmets vary. ....above a minimum in standards that specify the vertical drop test. |
#14
|
|||
|
|||
Wear a helmet, you know it makes sense
On 24/02/2019 14:52, Simon Jester wrote:
Bullet energy is usually specified in Foot-Pounds or Newton-Metres. A typical 9mm pistol round has a muzzle energy of 500 joules. The clue here is that a Newton-metre is a Joule. |
#15
|
|||
|
|||
Wear a helmet, you know it makes sense
On 24/02/2019 14:44, Simon Jester wrote:
On Sunday, February 24, 2019 at 12:59:30 PM UTC, RJH wrote: On 24/02/2019 11:55, GB wrote: On 23/02/2019 19:27, Simon Jester wrote: On Saturday, February 23, 2019 at 12:49:54 AM UTC, MrCheerful wrote: https://www.theargus.co.uk/news/1745...afety-warning/ What evidence do you have to show a cycle helmet would have made any difference? Research shows cycle helmets can only absorb 70 joules before failing and it takes around 1000 joules to crack a human skull. They sound like very focussed Joules - bullet perhaps? ;-) How many joules does it take to cause a catastrophic bleed on the brain, though? I'm not sure what you mean by 'before failing'? Does that mean the helmet cannot absorb more than 70 joules altogether? Or it cracks but still absorbs some of the impact? Depends on the incident and circumstances, of course. And clearly helmets vary. Indeed - and I at least find it difficult to tell what's what (I use an Aldi own brand). I gather this is a good guide: https://www.smf.org/home Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. I assume you always wear a helmet, not just when cycling. Nope, just cycling, motorbiking and skiing. -- Cheers, Rob |
#16
|
|||
|
|||
Wear a helmet, you know it makes sense
On 24/02/2019 20:12, Ian Smith wrote:
On Sun, 24 Feb 2019 12:59:26 +0000, RJH wrote: Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. What if wearing a helmet makes things worse in certain circumstances? How do you determine that the circumstances that it makes worse are less prevalent or less serious than the ones where it helps? I can't think of a single likely circumstance where wearing a helmet would make a cycling injury worse. Suppose I had some sort of lucky talisman that would protect you from all injury if you ever fell off your bike with no other vehicle around, but it made it twice as likely that you'd be hit by each car that overtook you. Would you want one of your own? Your logic (i.e. that it helps in certain circumstances, so must be good) suggests you'd want the talisman, even though it nearly doubles the chances of your death each time you go out riding (cyclists rarely die without interaction with a motor vehicle). Not sure I see your point there. Are you saying wearing a helmet makes me twice as likely to be hit by a car? Cycle helmets are designed to help in the sort of impacts that arise from falling off. They aren't designed to achieve very much in a motor vehicle impact. That's why they have disclaimers on them saying they aren't suitable for motor sport. 'Falling off' and 'vehicle impact' often happen at once, I'd have thought? -- Cheers, Rob |
#17
|
|||
|
|||
Wear a helmet, you know it makes sense
On 24/02/2019 20:54, Rob Morley wrote:
On Sun, 24 Feb 2019 12:59:26 +0000 RJH wrote: Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. But what about the circumstances when a helmet can be harmful? Rotational brain trauma can be more damaging than direct impact, for example. And did you know that you might be more likely to be hit by a car if you're wearing a helmet? Ah, no, I didn't know that. Why might that be likely? Is this evidenced at all, or some theory extrapolated? Bicycle helmets are designed to protect from impact in rather specific circumstances which roughly equate to toppling over at low speed and hitting your head on the kerb. Beyond that there's no guarantee that a helmet will provide any protection at all. I'm not looking for a guarantee - just protection in certain circumstances. Now in all my years of cycling (some while wearing a helmet) I've never encountered those specific circumstances. I've fallen off in a variety of ways, some of them fairly high-energy resulting in broken bones, but I've never thought a helmet saved my brain, or would have if I'd been wearing one. It's possible that a helmet might have helped the chap in the story, but that has to be one of the rare examples - sufficiently noteworthy that it got in the paper. And my personal experience echoes yours. But given the low cost and hassle, I'd rather wear a helmet and not rely on a sample of one to inform my safety-related decisions. -- Cheers, Rob |
#19
|
|||
|
|||
Wear a helmet, you know it makes sense
On Monday, February 25, 2019 at 9:43:39 AM UTC, RJH wrote:
On 24/02/2019 14:49, wrote: On Sunday, February 24, 2019 at 2:44:27 PM UTC, Simon Jester wrote: Common sense tells me that a cycle helmet can help in certain circumstances - and it's worth wearing one on that basis. I assume you always wear a helmet, not just when cycling. That is why they have killed several children in playgrounds. https://www.cyclehelmets.org/1227.html Do you have the figures for children saved? Nobody has those figures. QUOTE: "A doctor in Sweden lamented, with regard to strangulations in that country and its child helmet law, "We know we have killed, but we can't show we have saved anyone". (Sweden, 1) |
#20
|
|||
|
|||
Wear a helmet, you know it makes sense
On Monday, February 25, 2019 at 9:32:30 AM UTC, RJH wrote:
On 24/02/2019 14:44, Simon Jester wrote: I assume you always wear a helmet, not just when cycling. Nope, just cycling, motorbiking and skiing. Michael Schumacher would probably like to comment on that if he could. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Wear a helmet, you know it makes sense. Especially after a few drinks. | Mrcheerful | UK | 5 | October 28th 13 01:56 PM |
Always wear a helmet, she knew it made sense | Mrcheerful[_2_] | UK | 0 | October 24th 11 12:56 PM |
It only makes sense! | Fred2 | UK | 73 | April 28th 11 03:33 AM |
Now it Makes Sense | Davey Crockett | Racing | 0 | June 17th 07 10:01 AM |
This Makes To Much Sense | Art Deco | Mountain Biking | 0 | January 27th 05 03:50 PM |