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Two important things about helmets: 1. Helmets are very very useful if you're riding fast. In fact they are mandatory in all cycling sports. However most peopl

by carlob 11y ago

Two important things about helmets: 1. Helmets are very very useful if you're riding fast. In fact they are mandatory in all cycling sports. However most people don't commute to work going much faster than they would if running, hence they are not very useful for them. 2. In countries where helmets are compulsory, the chilling effect of risking a fine for not wearing a helmet has meant a decrease in the number of cyclists. Now, since bike accidents are relatively rare, but the health effects of cycling to work rather than driving benefit every single cyclist, helmet laws tend to have a negative effect on public health. This said, whenever I'm going for a sporty ride (longer, or faster than usual) I usually wear a helmet. When riding 5 minutes to meet a friend for a beer I don't.

RyanMcGreal 11y ago
As a corollary to your point #2, there is a clear safety in numbers effect in which as the number of cyclists goes up, the rate - and often the absolute number - of crashes and injuries goes down.
- carlob 11y ago
  Yes I was going to edit to add that, but you beat me to the punch. http://www.ncbi.nlm.nih.gov/pubmed/18481926 http://www.ncbi.nlm.nih.gov/pubmed/18481926
wtbob 11y ago
> Helmets are very very useful if you're riding fast. I can't find a reference with a short Googling, but as I recall helmets only help in a fairly narrow window, something like 18-23 mph or so. If one's going sufficiently fast, they're unable to do much good (because the forces are too much for a flimsy assembly of foam and plastic to reduce enough to prevent injury or death). > In fact they are mandatory in all cycling sports. They're the equivalent of a elephant-repelling rock.
- radu_floricica 11y ago
  > I can't find a reference with a short Googling, but as I recall helmets only help in a fairly narrow window, something like 18-23 mph or so I'd really like a citation on that. I'm into motorcycles and while helmet design is different, every motoGP season has plenty of examples of riders tumbling at +100kph and walking away after.
  - _ph_ 11y ago
    The problem is, almost any non-biking helmet is way better than the usual biking-helmets. So no conclusion can be gained from those for biking.
- UnoriginalGuy 11y ago
  I too would like a citation. Plus calling a bike helmet's foam "flimsy" makes me question your argument. If you've ever removed the outer plastic (which is designed to crumble), you'd know that the foam is extremely tough. You could likely make the argument that over a certain speed your other body parts will sustain large enough injuries for the bike helmet to not matter, but that's not what you're arguing, you're arguing that the bike helmet itself stops working at an extremely low speed of 23 MpH or above. I actually Googled this a bit. Cannot find anything on it.
  - wtbob 11y ago
    Ah, here's one from a pro-helmet resource: http://www.bhsi.org/limits.htm http://www.bhsi.org/limits.htm It indicates that helmets in the U.S. are only tested for 14 mph impacts. It's not that the helmet stops working altogether, it's that the helmet's protection really isn't sufficient. It'd be better to wear a full-face motorcycle helmet, but of course that'd be miserable on a bike.
- barrkel 11y ago
  Helmets are generally designed to handle the vertical component of the fall, not your forward velocity. If your torso hits a solid object at 30mph, there's about ~50% chance you'll rupture your aorta[1]. Hit something like a narrow signpost pole at 30mph and you'll be in a whole world of trouble - I'd post a link to a thread on a motorcycle forum, but it's a bit grisly. Guy survived, but he had to be opened up to treat the internal injuries. Motorcycle helmets have mostly the same minimal impact requirements of preventing brain injury from the vertical component, but also need plenty of abrasion resistance. [1] I heard this on London Met police BikeSafe day, a day-long course where London police do a presentation to motorcycle riders and go on an ride with a police observer. But for specific reference, see http://www.nhtsa.gov/people/injury/research/pub/HS809012.html http://www.nhtsa.gov/people/injury/research/pub/HS809012.htm... - "UK Department of Transport Traffic Advisory Leaflet 7/93 (TAU, 1993), figures quoted are, for 20 mph impact speeds: 5 percent death, 65 percent injured, and 30 percent uninjured; for 30 mph impact speeds: 45 percent death, 50 percent injured, and 5 percent uninjured"
csn 11y ago
In Finland, wearing a helmet while bicycling is required by law, but there aren't any penalties set for not complying. Maybe this appeals to people whose moral includes unconditional law-abiding.
tetraodonpuffer 11y ago
helmets are really useful if you are riding slow too, I was pulling out of a driveway, there was a little bit of black ice that I didn't see, my front wheel went out from me and before I knew it I was down: could not react, one second I was upright, the next second I was on my side and yes, my helmet was cracked by this fall (hit the side of my head on the cement), if I didn't have it it'd have been a much worse day than the very mild headache I got from it. I really don't understand all these "helmets don't help" folks, having ridden motorcycles and bikes all my life you would not catch me dead without a helmet: a helmet is not an invulnerability cloak but in the end if you fall down and hit your head and you don't have one, you are not going to be in a good place, whether you are going at walking speed or 30mph.
- spatulan 11y ago
  The reason some are sceptical, is the extra weight and leverage of the helmet is supposed to increase the chance of you breaking your neck in in accident. I have no idea if its true or not.
- carlob 11y ago
  Then why don't you wear a helmet when you're walking on ice as well? I'm not saying helmets don't work, I'm saying it's not very likely to hit your head at high velocity on the ground if you were going 10 km/h. And if that means you're not gonna ride a bike at all because you forgot your helmet you're probably having a higher risk of cardiovascular disease further down the line than you have of breaking your head now.
  - arethuza 11y ago
    Well, I do wear a helmet while skiing - largely because I witnessed an accident where a stationary skier was hit on the head by a flailing T-bar.
  - falcolas 11y ago
    Having known someone who died to a head injury from falling down from a standing position; speed matters little, other than giving you more time to react. Just the acceleration from gravity is enough to fuck your head up pretty badly. Head injuries are nothing to take lightly.
ebbv 11y ago
I don't buy the idea that requiring helmets truly reduces the number of riders long term. The kind of person who would not ride their bike because they don't want to wear a helmet is the kind of person who was only going to die for a couple of months anyway. Every dedicated rider I know wears a helmet, required or not.
- carlob 11y ago
  Take a trip to any large city with a bike sharing program (say Paris or NYC) and you'll thousands of people renting a bike for a short ride, maybe just because they've missed the bus. As far as I know bicycle fatalities in Paris have gone down since the program was introduced even if the number of bikes on the road has increased by an order of magnitude. Also you might not buy it, but the data is out there… 30% fewer cyclists in NZ and Australia http://www.fubicy.org/spip.php?article191 http://www.fubicy.org/spip.php?article191
- Piskvorrr 11y ago
  Aye, there's the rub. I would not call myself a bicyclist, and certainly not a dedicated one. I just ride bikes when it's convenient: there's a pretty good public transport network around my city, you can walk short distances, and car traffic is also reasonable; biking supplements these three options very nicely, esp. now that there's a bike-sharing thing in the city (unlock a bike via an app, ride it wherever, lock it via the app again, minimal fuss). Lugging a helmet around, just in case I should decide to use a bike, is rather inconvenient (I tried). If there were a mandatory helmet law, it would certainly increase the gap between "casual rider" and "dedicated bicyclist," driving out people like me. (OTOH, if I'm on a bike trip, I do have my helmet, as I usually go beyond paved streets, longer distances and probably higher speeds. Different tools for different purposes.) TL;DR: assuming "bicycling requires dedication" reduces ridership by definition.
- biehl 11y ago
  What kind of riders are you thinking of? In Copenhagen, where everyone rides bikes (young, old, hipster, business guy, dad, child - not only "dedicated riders"), there are plenty who would bike less by simply dropping some bike rides if they choice was between bike+helmet and eg. walking, bussing or cardriving.
frabbit 11y ago
I think it's worth mentioning that re #1 this is because of the increased probability of falling off while riding at the limits of human reaction in a dense pack. It is also worth noting that there is no demonstrated prophylactic effect from wearing a helmet in those situations for life-threatening head injuries.

by carlob 11y ago

RyanMcGreal 11y ago

As a corollary to your point #2, there is a clear safety in numbers effect in which as the number of cyclists goes up, the rate - and often the absolute number - of crashes and injuries goes down.

carlob 11y ago
Yes I was going to edit to add that, but you beat me to the punch. http://www.ncbi.nlm.nih.gov/pubmed/18481926 http://www.ncbi.nlm.nih.gov/pubmed/18481926

wtbob 11y ago

> Helmets are very very useful if you're riding fast. I can't find a reference with a short Googling, but as I recall helmets only help in a fairly narrow window, something like 18-23 mph or so. If one's going sufficiently fast, they're unable to do much good (because the forces are too much for a flimsy assembly of foam and plastic to reduce enough to prevent injury or death). > In fact they are mandatory in all cycling sports. They're the equivalent of a elephant-repelling rock.

radu_floricica 11y ago
> I can't find a reference with a short Googling, but as I recall helmets only help in a fairly narrow window, something like 18-23 mph or so I'd really like a citation on that. I'm into motorcycles and while helmet design is different, every motoGP season has plenty of examples of riders tumbling at +100kph and walking away after.
- _ph_ 11y ago
  The problem is, almost any non-biking helmet is way better than the usual biking-helmets. So no conclusion can be gained from those for biking.
UnoriginalGuy 11y ago
I too would like a citation. Plus calling a bike helmet's foam "flimsy" makes me question your argument. If you've ever removed the outer plastic (which is designed to crumble), you'd know that the foam is extremely tough. You could likely make the argument that over a certain speed your other body parts will sustain large enough injuries for the bike helmet to not matter, but that's not what you're arguing, you're arguing that the bike helmet itself stops working at an extremely low speed of 23 MpH or above. I actually Googled this a bit. Cannot find anything on it.
- wtbob 11y ago
  Ah, here's one from a pro-helmet resource: http://www.bhsi.org/limits.htm http://www.bhsi.org/limits.htm It indicates that helmets in the U.S. are only tested for 14 mph impacts. It's not that the helmet stops working altogether, it's that the helmet's protection really isn't sufficient. It'd be better to wear a full-face motorcycle helmet, but of course that'd be miserable on a bike.
barrkel 11y ago
Helmets are generally designed to handle the vertical component of the fall, not your forward velocity. If your torso hits a solid object at 30mph, there's about ~50% chance you'll rupture your aorta[1]. Hit something like a narrow signpost pole at 30mph and you'll be in a whole world of trouble - I'd post a link to a thread on a motorcycle forum, but it's a bit grisly. Guy survived, but he had to be opened up to treat the internal injuries. Motorcycle helmets have mostly the same minimal impact requirements of preventing brain injury from the vertical component, but also need plenty of abrasion resistance. [1] I heard this on London Met police BikeSafe day, a day-long course where London police do a presentation to motorcycle riders and go on an ride with a police observer. But for specific reference, see http://www.nhtsa.gov/people/injury/research/pub/HS809012.html http://www.nhtsa.gov/people/injury/research/pub/HS809012.htm... - "UK Department of Transport Traffic Advisory Leaflet 7/93 (TAU, 1993), figures quoted are, for 20 mph impact speeds: 5 percent death, 65 percent injured, and 30 percent uninjured; for 30 mph impact speeds: 45 percent death, 50 percent injured, and 5 percent uninjured"

csn 11y ago

In Finland, wearing a helmet while bicycling is required by law, but there aren't any penalties set for not complying. Maybe this appeals to people whose moral includes unconditional law-abiding.

tetraodonpuffer 11y ago

helmets are really useful if you are riding slow too, I was pulling out of a driveway, there was a little bit of black ice that I didn't see, my front wheel went out from me and before I knew it I was down: could not react, one second I was upright, the next second I was on my side and yes, my helmet was cracked by this fall (hit the side of my head on the cement), if I didn't have it it'd have been a much worse day than the very mild headache I got from it. I really don't understand all these "helmets don't help" folks, having ridden motorcycles and bikes all my life you would not catch me dead without a helmet: a helmet is not an invulnerability cloak but in the end if you fall down and hit your head and you don't have one, you are not going to be in a good place, whether you are going at walking speed or 30mph.

spatulan 11y ago
The reason some are sceptical, is the extra weight and leverage of the helmet is supposed to increase the chance of you breaking your neck in in accident. I have no idea if its true or not.
carlob 11y ago
Then why don't you wear a helmet when you're walking on ice as well? I'm not saying helmets don't work, I'm saying it's not very likely to hit your head at high velocity on the ground if you were going 10 km/h. And if that means you're not gonna ride a bike at all because you forgot your helmet you're probably having a higher risk of cardiovascular disease further down the line than you have of breaking your head now.
- arethuza 11y ago
  Well, I do wear a helmet while skiing - largely because I witnessed an accident where a stationary skier was hit on the head by a flailing T-bar.
- falcolas 11y ago
  Having known someone who died to a head injury from falling down from a standing position; speed matters little, other than giving you more time to react. Just the acceleration from gravity is enough to fuck your head up pretty badly. Head injuries are nothing to take lightly.

ebbv 11y ago

I don't buy the idea that requiring helmets truly reduces the number of riders long term. The kind of person who would not ride their bike because they don't want to wear a helmet is the kind of person who was only going to die for a couple of months anyway. Every dedicated rider I know wears a helmet, required or not.

carlob 11y ago
Take a trip to any large city with a bike sharing program (say Paris or NYC) and you'll thousands of people renting a bike for a short ride, maybe just because they've missed the bus. As far as I know bicycle fatalities in Paris have gone down since the program was introduced even if the number of bikes on the road has increased by an order of magnitude. Also you might not buy it, but the data is out there… 30% fewer cyclists in NZ and Australia http://www.fubicy.org/spip.php?article191 http://www.fubicy.org/spip.php?article191
Piskvorrr 11y ago
Aye, there's the rub. I would not call myself a bicyclist, and certainly not a dedicated one. I just ride bikes when it's convenient: there's a pretty good public transport network around my city, you can walk short distances, and car traffic is also reasonable; biking supplements these three options very nicely, esp. now that there's a bike-sharing thing in the city (unlock a bike via an app, ride it wherever, lock it via the app again, minimal fuss). Lugging a helmet around, just in case I should decide to use a bike, is rather inconvenient (I tried). If there were a mandatory helmet law, it would certainly increase the gap between "casual rider" and "dedicated bicyclist," driving out people like me. (OTOH, if I'm on a bike trip, I do have my helmet, as I usually go beyond paved streets, longer distances and probably higher speeds. Different tools for different purposes.) TL;DR: assuming "bicycling requires dedication" reduces ridership by definition.
biehl 11y ago
What kind of riders are you thinking of? In Copenhagen, where everyone rides bikes (young, old, hipster, business guy, dad, child - not only "dedicated riders"), there are plenty who would bike less by simply dropping some bike rides if they choice was between bike+helmet and eg. walking, bussing or cardriving.

frabbit 11y ago

I think it's worth mentioning that re #1 this is because of the increased probability of falling off while riding at the limits of human reaction in a dense pack. It is also worth noting that there is no demonstrated prophylactic effect from wearing a helmet in those situations for life-threatening head injuries.