Building a Better Bike Helmet Out of Paper 317
An anonymous reader writes "Inspired by nature, a London man believes the solution to safer bike helmets is to build them out of paper. '"The animal that stood out was the woodpecker. It pecks at about ten times per second and every time it pecks it sustains the same amount of force as us crashing at 50 miles per hour," says Surabhi. "It's the only bird in the world where the skull and the beak are completely disjointed, and there's a soft corrugated cartilage in the middle that absorbs all the impact and stops it from getting a headache." In order to mimic the woodpecker's crumple zone, Anirudha turned to a cheap and easily accessible source — paper. He engineered it into a double-layer of honeycomb that could then be cut and constructed into a functioning helmet. "What you end up with is with tiny little airbags throughout the helmet," he says.'"
Tiny little airbags like the polystyrene foam? (Score:5, Insightful)
I wonder how this compares? Does this absorb more energy?
Re:The best bike helmets (Score:5, Insightful)
Sometimes it`s not your fault.
Re:Bike helmet? (Score:3, Insightful)
Also, 4) many severe head injuries from cycling crashes are caused by rotational forces, which helmets can exacerbate. 5) helmet requirements almost universally reduce the number of cyclists (or reduce the growth in cycling), leaving the cycling pool with more adventurous and risk-prone bikers; 6) corollary of #5, fewer cyclists means less road time experience between cyclists and car drivers.
See http://cyclehelmets.org/.
Re:Bike helmet? (Score:5, Insightful)
I hate to say it, but my impression is that linking to http://cyclehelmets.org/ [cyclehelmets.org] for issues of helmets is like linking to WUWT for issues on climate change. It has a particular position, and runs with it (whether that is intentional or not). They are by no means unique in this, and are also not the only position in the discussion to do it.
That said:
1. Dumb cyclists will be dumb, and if someone rides less cautiously because they think a helmet will protect them they are dumb
2. Dumb drivers will be dumb, and if a driver is really driving less cautiously around a cyclist on the basis that a helmet will protect the cyclist they are not only dumb but outright dangeous
3. Crossing the threshold with 100% of the force is still probably going to be more damaging than crossing it with 50% of the force (if 50% is absorbed by the helmet)
4. And many are caused by non-rotational impacts, which helmets reduce
5. Dumb cyclists are dumb, and if the pool of cyclists is largely made up of dumb cyclists then that doesn't mean helmets reduce safety, just that if a bunch of less dumb cyclists were added to the pool they would dilute the apparent stupidity of the group overall. Not saying cyclists are stupid, but rather that the number of stupid cyclists is the same irrespective of whether it is 100 stupid cyclists in 101 total cyclists, or 100 stupid cyclists in 1000 total cyclists.
6. If #5 is in fact true (and there is little agreement on it) then this is true, and indeed having more cyclists on the road very likely does make it safer for all cyclists.
There in another arguments for not requiring helmets, also based on the idea that requiring helmets reduces the number of cyclists: even if helmets do reduce the likelihood of death or brain injury in an accident, the advantage of improvement in overall community health as a result of more cyclists offsets the disadvantage of a subset of these being dead or brain injured.
Re:Bike helmet? (Score:4, Insightful)
The science is not a slam dunk for helmets. In many studies--including more recent studies, and meta-studies--helmets increase the injury rate. But even assuming that helmets provide a significant net benefit for cyclists, the reduction in cyclists caused by helmet laws definitely outweighs the benefits of helmets, because the injury rate is so low even without helmets that you're better off having a bunch of helmet-less cyclists losing weight and increasing their cardiovascular health.
Once again intuition and anecdote provide the wrong answer.
People eschewed seat belts for similar reasons--intuitively everybody thought that a seat belt would increase injury by preventing you from escaping from a wreckage, or by keeping you in a poor position.
People: stop using your intuition for this kind of stuff, and read up on real science. And also be critical of the science, because too often even scientists inadvertently seek to prove their intuition, rather than asking the hard questions. In the case of helmets, the emerging, qualitatively better science casts serious doubt on the overall benefits of helmets from an epidemiological perspective.
Helmets will help prevent cuts and mild concussions, but not serious head injuries with permanent damage, which they might even exacerbate. And helmet requirements disincentivize cycling to an extent that they often cause a negative net health outcome in the population.
Takeaway: helmet laws are definitely a bad idea. If you wear a helmet, good for you, but don't judge others who don't.
Re:Bike helmet? (Score:5, Insightful)
Also, 4) many severe head injuries from cycling crashes are caused by rotational forces, which helmets can exacerbate. 5) helmet requirements almost universally reduce the number of cyclists (or reduce the growth in cycling), leaving the cycling pool with more adventurous and risk-prone bikers; 6) corollary of #5, fewer cyclists means less road time experience between cyclists and car drivers.
See http://cyclehelmets.org/.
You're just trying to rationalize your personal dislike for helmets.
Saying helmets don't protect your head is like saying water isn't wet. It's fucking risible. Trying to prove helmets don't protect by using statistics from different groups (cyclists who wear helmets are a different type of rider from cyclists who don't) smacks of desperation.
Tell you what. I get to smack you upside your granite skull with a car door. You can put on a helmet or not. Your choice.
But the brain damage has already been done.
Re:Bike helmet? (Score:5, Insightful)
Your post is based on the assumption that car-cyclist collisions are the only significant kind of accident.
I've gone down because of ice (x2), rain, and recklessness. If you'll look up the statistics, you'll see that borne out in the larger numbers as well.
And human-caused climate change is real. Watch insurance prices rather than listening to politicians that are owned by the oil and coal industries.
Re:Rain (Score:5, Insightful)
I actually thought about that. However, there are very few cost effective methods of waterproofing paper that work. Think of the waterproof corrugated paper packaging you have seen. It is fine for short exposure; but, it does not hold up to prolonged immersion and exposure.
A bike helmet will sit in puddles; it will spend hours in downpours. If you waterproof for the exposure conditions that bicycle helmets see, at some point it ceases to be paper.
Re:Bike helmet? (Score:5, Insightful)
Why do these arguments sound so familiar? Probably because they're so similar to the arguments people used to make against seat belts.
"They'll increase accidents because they make it harder for drivers to stretch and look around!"
"They'll trap me in a burning or sinking car!"
And, my all-time personal favorite (yes, I've actually heard people say this):
"They'll prevent me from being thrown clear of the collision!"
People will persistently find the very stupidest reasons for not doing something that bugs them. Yes, each of these eventualities might have killed a few drivers who would've been spared if not for their safety belts. But those numbers are absolutely dwarfed by the number of lives saved and serious injuries prevented.
I've only been in one significant bike accident, and I was lucky enough in that one that my helmet didn't come into play. But looking back at the accident and the pattern of my injuries, I can't explain how the helmet was spared. I sure as hell am not tempted at this point to ride out without it.
Re:don't ride in the rain (Score:5, Insightful)
Because you know... you can't apply a waterproof coating. We don't use paper to wrap up all kinds of wet things, like milk, or orange juice.
Re:Bike helmet? (Score:5, Insightful)
I am a regular biker — At least three days a week, I cycle to work. Not a great distance, but I end up making ~1hr on the bike every day I use it.
Several years ago, a car hit laterally my rear tire. Quite slowly, fortunately, although it managed to bend the rim ~30 degrees. Of course, cycling at ~20Km/h (~12mph), I fell down to my left.
I stood up right away, scared but not hit. My pants were slightly torn over the pocket where I store my keys. Nothing happened to me, just a scare, right?
When I took my helmet off, it was split in two. Yes, helmets are (and are designed to be) quite more fragile than skulls. Still, I'm very happy I didn't have to land with the side of my head on the road. Were I to be lucky, I'd have an ugly scar on my front left side.
Wear a helmet. Always.
Re:Old news, but good news (Score:5, Insightful)
Looks like it has a fatal flaw or two.
It's no great trick to make a helmet which will absorb impact. The trick is to do it without too much weight and, unless you only ride in cold weather, without overheating your head. In general, the more you pay for a helmet, the less helmet and more hole you get. That thing is covered with a solid shell. No venting. It's a portable oven. It's also 535g -- about 1.2 pounds. It's a brick (and probably will contribute to neck injuries as a result).
Giro's cheapest MTB helmet has some vents and is 410g. Move up to a helmet you might actually wear in the heat, you've got almost as much vent as helmet and you're down to 316g. Go to one which costs as much as this one -- 80 pounds sterling -- and you're under 300g and have more holes than helmet.
If it was just unventilated it might still have its niche, but it's just too heavy.
Re:Bike helmet? (Score:5, Insightful)
They argued against it in the beginning. I remember reading about those idiots, and even now, there are people who'd use those arguments. They need to be loudly and derisively laughed at.
Re:Bike helmet? (Score:5, Insightful)
Don't confuse the questions of "should I wear a helmet" with "should helmets be compulsory".
Same with drugs - laws can make things worse, despite good intentions.
Re:Bike helmet? (Score:5, Insightful)
No it isn't. If somebody crashes wearing a helmet and the side of the helmet is smashed in but the rider is OK then it's assumed that the helmet saved them. That happens enough for it to be worth it.
I remember hearing this same stupid argument about motorcycle helmets, seatbelts and lawnmowers with naked blades. An easily complied with safety feature does not have to stop 100% of injuries to be worth it.
Re:Bike helmet? (Score:2, Insightful)
In today's world, saying that something is a good idea is tantamount to saying it should be compulsory. And if you object and tell them it's none of your business, they'll point to healthcare costs and say it is.
Re:Tiny little airbags like the polystyrene foam? (Score:5, Insightful)
15 mph = 6.7 m/s. 220 Gs = 220*9.81 m/s^2 = 2158 m/s^2. To generate 220 Gs decelerating from 6.7 ms, you need to decelerate in 6.7 / 2158 = 0.003 sec.
At a constant deceleration, that's a distance of v^2 = 2ad, or d = v^2 / 2a = (6.7)^2 / (2*220*9.81) = 0.0104 meters = 1 cm.
To generate 70 Gs, you need to decelerate in 6.7 m/s / (70*9.81 m/s^2) = 0.0098 sec.
At a constant deceleration, that's d = v^2 / 2a = (6.7)^2 / (2*70*9.81) = 0.0327 meters = 3.3 cm.
The speed at which polystyrene springs back is so slow you almost need time lapse photography to watch it (crush a styrofoam coffee cup and see how long it takes to uncrush itself). The decreased G forces are entirely due to the distance the structure collapses. Polystyrene is a stiffer, closed-cell material with limited deformation due to the cells resisting popping (indeed, breakage is usually due to adjacent cells shearing apart, rather than the cells popping). While cardboard is essentially open cell and more likely to collapse its entire thickness.
That's a double-edged sword though. The cardboard helmet is more likely to be ruined or structurally compromised from lesser impacts, like having the bike fall on top of it while you're transporting it in the back of your truck. Stuff the polystyrene helmet can survive because such impacts do not have sufficient force to pop the cells or shear adjacent cells. The air in the cells just gets compressed more, and springs the cell back to shape once the load is removed. Since the cardboard is open cell, it has to rely entirely upon the paper's ability to spring back to shape to survive such loads intact.
And (judging from the pictures) if you hit at the wrong angle, you can cause the cardboard to collapse by twisting and falling over rather than crushing, thus greatly reducing its protection. Standardized tests are great in that they're reproducible, but they suck because by always testing in the exact same manner you allow designers to optimize for the test instead of for real-life conditions. i.e. You can improve performance in tested orientations by reducing crash protection in non-tested orientations. The more solid structure of polystyrene allows forces to be better transmitted between cells thus helping even out its crash protection at all orientations. The cardboard helmet looks like it's traded off that uniformity for anisotropic crash protection which peaks in the orientations which are being tested (longitudinal and transverse). A better design would mesh the cardboard into triangles, not squares. Squares are notorious for collapsing without using any of the structural material's innate strength. It's why the most common fiberglass weaves are 0/30/60 degrees, or 0/90 layered at 30 or 45 degree increments so you're not putting all your strength along just 0 and 90 degrees like this cardboard helmet does).
Re:Bike helmet? (Score:4, Insightful)
I do take issue with one detail, though: the assumption that helmet laws will disincentivize cycling.
It's no assumption -- it's a statistically demonstrated fact. In places where helmet laws are passed, cycling does decrease, whether or not there's a good reason that should necessarily happen.
But if you want to know why its different from seatbelt laws, note that seatbelt laws came about in two stages -- first, manufacturers were required to provide seatbelts in every vehicle sold. Then, after almost every vehicle on the road had seatbelts, drivers and passengers were required to use them. The first step, while slightly increasing the price of a new vehicle, didn't cause anyone any practical inconvenience -- anyone who didn't believe in them might grumble a bit about being forced to pay for them (it's not like one would actually refuse to buy a $xxxx car over a $x addition), but he didn't have to use them. And because of the first step, the second step had no up-front cost or inconvenience -- you did have to buckle up every time, but the seatbelt was right there, no need to run down to the garage and get one installed. (AIUI, there are/were exemptions from seatbelt wearing laws in any cars old enough to have legally been sold without seatbelts, and at any rate they were a tiny fraction of the fleet by then.) So neither step caused motorists to quit motoring, especially since most of them had no practical alternative for traveling the same distance.
In contrast, many cyclists who presently ride helmetless have no helmet, and if a mandatory helmet law were passed, they'd have to make time to get to the bike shop and buy one or quit riding -- and if, like many cyclists, you've already got a car that satisfies all your functional transportation requirements, quitting is by far the easier option.
Fight now and fight hard! (Score:2, Insightful)
I'm a motorcyclist, not a bicyclist (currently). For years non-motorcyclists enforced a law on us requiring the use of a helmet. This is not simply a safety issue and shouldn't even get to an argument of 'for' or 'against', it's a freedom of choice issue. As an adult you have the right to choose, or you should have. As a caveat, I'm not totally against helmet use or the safety they bring and I wear a helmet on my motorcycle probably at least 60-80% of them time depending. I have friends whose lives were saved wearing a helmet and I have friends that died from the use of one through rotational torque to his neck and spine. The issue at hand is not about the relative safety or danger of helmet use; it should be about CHOICE.
Choice is a freedom, and once lost I can attest to how difficult it is to regain. Allow people to make their own INFORMED choices, do not legislate it. Regardless on which side of this issue you come down on we should all be able to agree that forcing 'good behavior' on a full grown adult is wrong.
Re:Rain (Score:0, Insightful)
Let's say your current polystyrene helmet was flawed and is full of hairline cracks, but has enough structural integrity to hold together.
Let's say it was made of straw, and built in the shape of a man.