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> 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 wind

by 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"

by wtbob 11y ago

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"