Bicycle helmets are mostly designed for slow, vertical falls. The testing methodology is to drop the weighted (11 lbs/5 kilos) helmet from a height of 1.2 meters onto a round anvil and/or a curb-shaped anvil and from a height of 2 meters onto a flat anvil. The headform measures the amount of impact attenuation when the helmet comes to rest, expressed in joules. A helmet which “passes the test” can permit a maximum of 98 joules at the headform. Failure threshold is 300 g, which happens to be the level at which you can expect to lose consciousness, and probably suffer some injury which hopefully will not be permanent.
Real world impacts are going to look a lot different from the testing methodology in that they are much more likely to include: multiple impacts, irregularly shaped “anvils,” and rotational forces (think crack the whip or water skiing outside of the wake when the boat turns). Real world impacts are also much more likely to occur with some significant horizontal speed (which has both advantages and disadvantages).
I bought my first helmet in about 1988. It was a thick styrofoam, poorly vented Specialized helmet which had a nylon fabric cover stretched over it and bore certification stickers to the 1984 Snell and ANSI standards. The unfinished styrofoam design was abandoned within five years for the hard shell finish due to the observation of increased neck and brain injury related to rotational forces exerted upon a helmet which was too “grippy” when it contacted pavement.
Riding a bicycle can improve cardiovascular fitness and improve Body Mass Index, but it doesn’t change certain hard-wired physiological traits or cognitive functions that assist in making you a “safer” bicyclist. We all have differences in strength (including the composition of slow-twitch vs. fast-twitch muscles), balance, visual acuity, (including depth perception and ability to detect motion), hearing, proprioception, and judgment, to name just a few. I have seen at least a half a dozen bicyclists in the past week, after dark, wearing a helmet, with no lights on the front or the back of their bicycle. I have told two of them they’re going to need a bigger helmet.
As stated, I am opposed to head injuries and particularly traumatic brain injuries. My brain has remained a solid second on my list of favorite organs since adolescence. If I’m ever in a bicycle accident with a car, I want to be dressed like the guy in “The Hurt Locker.” Most studies of the efficacy of bicycle helmets have found them to be effective at reducing the risk of head injury. In my estimation, that takes the risk down from remote to infinitesimal.
Mandatory helmet laws increase the rate of helmet use, but reduce the number of cyclists on the road (Australia, New Zealand, Canada - British Columbia and Nova Scotia).
More cyclists on the road make all cyclists safer. In 1994, 796 bicyclists were killed in crashes with motor vehicles; in 2009, 630 bicyclists were killed in crashes with motor vehicles (-21%). Trips by bicycle have increased from 0.7% in 1990 to 1.0% in 2009 (+43%).
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I'm not sure I can agree with this. I realize that there could be some truth to the notion that we go on "autopilot" when we take the same route over and over, however, taking the same route seems good for me. My commute has a lot of stops (I'm a dog walker) and I'm on a somewhat tight schedule. No one wants me to get to their house after 4 pm, so being on the same route allows me avoid anything unexpected--crossing a main arterial street, riding on a road that's full of potholes, dealing with riding through a school zone at 2:30--just for a few examples.
I've found that after years of riding the same roads every day of the week, I am more likely to *know* the road. I know where the potholes are, where the sight lines might be tricky, when there's a difficult intersection, when I have to encounter lots of kids after school, etc. It's sometimes a surprise when a road I usually take is being repaved but other than that, I can't say that there are many times when I'm zoned out on my bike. At least not while I'm actually moving.
Complacency seems a lot more likely when I'm in the car. I have had cancellations on my dog walking route and I'll still drive as if I'm going to the client who canceled. For some reason, when I'm on my bike, this never happens. I always know where I'm going and I like knowing the route's going to basically stay the same. I've been tweaking it for years (because clients come and go) and when I do that it gets better all the time, too.
Good post. As someone who's specialized in brain injury rehabilitation, I tend to mention diapers before disruption to traffic.
Back and neck braces are seen more often in the motorized 2-wheel safety community and are commonly used in racing today. I wonder why they are not yet pushed by the bicycle safety community or is Big Neckbrace not as heavily into donating large sacks of money to "Bicycle Safety" as Big Helmet is?
Please expand on this thought.
Michael Perz said:Since this discussion has grown to encompass cycling habits and not just the efficacy of helmets, it's probably worth mentioning this again. One of the best things you can do to ensure your own safety while riding is to frequently change your routes to common destinations. Print that sentence and tape it to the inside of your helmet.
Traffic disruption could be used as an argument for the government imposing helmet laws.
Yes, yes it could - used a ridiculous, ridiculous argument.
"I'm sorry, you legally need to wear this helmet."
"Why? You're concerned about my safety? Thank you! I appreciate that."
"No, we don't give a rat's ass about your safety. We just don't want an ambulance disrupting traffic to take you to the hospital."
Jamais716 said:
Traffic disruption could be used as an argument for the government imposing helmet laws.
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