Aldi - Helmets @ $69

[Falc&Send]

Has the nature of falling of a bike changed in the last 30 years? Of course it has! Modern sportbikes are faster than the GP bikes of that era, tyres alone mean club racers are capable of things that professionals could only dream of 30 years ago.

Is going faster really that relevant? If you smack your head into a wall/ground/whatever at 100mph isn't it going to hurt pretty much the same as 120mph or even 150mph?

[Gassed250]

I'm just not big on then singing it's praises on a forum where other people will get the idea that Aldi helmets are on par with something like a Shoei, purchase one then use it for an entirely different purpose.

thing is it may be on par with some of the lower spec Shoei units even with their Snell sticker, not all manufactures choose to have their product Snell certified, does this mean they are not up to standards or wont perform as well? I think not with Lorenzo's Nolan x-lite x-802 being a fine example of a non Snell certified helmet

For all we know the Aldi/Masei Helmet may pass the Snell test

actually was just having a look around the net and found that JDS/GDR (parent company) have attained Snell M2000 certification, though i doubt it applies to the Aldi/Masei 802

[gmh265]

How do these two compare? would either pass the snell testing?

[Gassed250]

combine the two and i think you'd have a winner

[Norminator]

Rorz' point all along has been that not all helmets are created equal, and I know he is absolutely right. Gassed alludes to that himself... he makes a pretty good point that doing 12s in his streeter isn't a situation where he feels endangered (nor would I) and he bought a lid satisfactory for the occasional job.

The Snell response covers a lot of the flaws in the article you keep preaching from. I suspect the cheaper lids wouldn't show the same resilience after 20000-30000km that some more expensive items do. If you don't feel the same way hrd, that is your prerogative. Like a few of the guys here no doubt, I have done a lot of k's with different helmets on, and I know what my choice is every time. 30yo data aside, you also said that DOT lids do a better job than Snell because of the Snell double impact test, 300G, etc. But as I mentioned to you, DOT allows 400G... so why aren't you up in arms about that, since 300 was outrageous?

hurr.. FIA 8860 uses a 225kj test. We've uncovered a conspiracy to retard Formula 1 drivers!

To me, your argument is about as sensible as, "cheap tyres are as good as expensive tyres, china turbos are superior to garrett, i can't believe you bought a 5-series when the commodore is an equal in every way."

Let's all just go for a ride. My new safety standard is no more prangs... it fucks up my expensive graphics.

[Rorz de Puniet]

how many times do you need to be told the article does not say anything like that?

also, exactly how heavy are those crashes? what force was measured in them?? did anyone study the helmets to determine what force they were subjected to??? if you don't know, what you are really saying is "look at these dramatic looking crashes..." Its not evidence of anything.

From the beloved article:

Even though many motorcycles were capable of running the quarter-mile in 11 seconds (or less) and topping 140 mph back in '81, not one of the 900-odd accidents investigated in the Hurt study involved a speed over 100 mph. The "one in a thousand" speed seen in the Hurt Report was 86 mph, meaning only one of the accidents seen in the 900-crash study occurred at or above that speed. And the COST 327 study, done recently in the land of the autobahn, contained very few crashes over 120 kph, or 75 mph. The big lesson here is this: It's a mistake to assume that going really fast causes a significant number of accidents just because a motorcycle can go really fast.

Another eye-opener: In spite of what one might assume, the speed at which an accident starts does not necessarily correlate to the impact the head—or helmet—will have to absorb in a crash. That is, according to the Hurt Report and the similar Thailand study, going faster when you fall off does not typically result in your helmet taking a harder hit.

How can this be? Because the vast majority of head impacts occur when the rider falls off his bike and simply hits his head on the flat road surface. The biggest impact in a given crash will typically happen on that first contact, and the energy is proportional to the height from which the rider falls—not his forward speed at the time. A big highside may give a rider some extra altitude, but rarely higher than 8 feet. A high-speed crash may involve a lot of sliding along the ground, but this is not particularly challenging to a helmeted head because all modern full-face helmets do an excellent job of protecting you from abrasion.

In fact, the vast majority of crashed helmets examined in the Hurt Report showed that they had absorbed about the same impact you'd receive if you simply tipped over while standing, like a bowling pin, and hit your head on the pavement. Ninety-plus percent of the head impacts surveyed, in fact, were equal to or less than the force involved in a 7-foot drop. And 99 percent of the impacts were at or below the energy of a 10-foot drop.

That's reassuring. Over 90% of the crashes examined in the report could have been replicated by taking a tumble when walking to the shops.


This bit is interesting:

We needed somebody to help us design the tests and do the actual testing. So we hired David Thom. Remember the Hurt Report? Thom was one of the USC researchers who went out to investigate all those motorcycle accidents and then helped pull it all together. Thom worked at USC with Professor Harry Hurt for many years, investigating all the various ways motorcyclists and other folk hurt themselves, and striving mightily to find better ways to protect them.

Thom subsequently formed his own company, Collision and Injury Dynamics. He has his own state-of-the-art helmet impact lab where he does impartial, objective certification testing for many helmet companies. The DOT standard, for instance, relies on companies certifying their own helmets, and Thom is one of the people they contract with to do the actual testing. In other words, he knows what he's doing.

So... one of the original authors of the Hurt report had imput into this impartial article. Interesting that he owns his own company that in doing helmet testing and certification would make him a direct competitor to Snell. The main difference being that Snell is a not for profit organisation where as Davey Thom's operation is a business. He'd have a massive amount to gain from discrediting Snell to the point where it was no longer recognised as the premium standard but I'm sure he'd never let that sway his opinion.

Snell stipulate more difficult tests to pass, but also allow the passing mark to be as high as 300G transferred to the headform in those tests, which according to medical, scientific and military opinion is not survivable. That sure is a higher level of testing

Even if the DOT maximum allowable transferred G's was lower than the Snell maximum allowed (which it seems may actually be incorrect anyway) what difference does it make if a third party doesn't test the helmets to make sure they actually conform to that standard? Fine for the companies that are doing the right thing but they are going to be the reputable companies anyway.

I wasn't aware of the 50mm roll bar test, but otherwise the impact tests and their conditions are identical:

the head forms are the same.
the extent of protection (ie areas covered by the helmet) are the same.
conditioning for testing is identical - special conditioning, cold, heat and wet conditioning... all identical.
positional stability (roll off) testing is identical
dynamic test of retention system is identical
motobike testing has special considerations for flip-up helmets in their Impact Management tests, but are otherwise identical.
the flat anvil, hemisperical anvil and edge anvil tests are identical
the permitted G forces in the anvil tests are identical
chin bar test is identical
shell penetration test is identical
face sheild penetration test is identical

given that the rest of the tests are identical in every aspect, I doubt a karting standard helmet is manufactured or engineered any differently to a motorcycle helmet to provide a different kind of impact protection.

I was aware of the extra flame test and different feilds of vision, which is why I said impact tests...

Here's something interesting from your article:

The DOT standard has acquired something of a low-rent reputation for a number of reasons. First, it comes from the Gubmint, and the Gubmint, as we know, can't do anything right.

The DOT standard, like laws against, say, murder, also relies on the honor system; that is, there's only a penalty involved if you break it and sell a non-complying helmet and get caught. Manufacturers are required to do their own testing and then certify that their helmets meet the standards. But it also gives helmet designers quite a bit of freedom to design a helmet the way they think it ought to be for optimum overall protection. The question is, how well are those designers doing their job with all that freedom?

So basically... I can chuck a DOT approval sticker on a helmet I designed and made in my shed, which hasn't had any third party testing done on it at all. Seems fair enough.

So as far as the Aldi (I know, I know they are made by Masei- but who the fuck are they and where are they making these helmets?) or any other non-known brand helmets go, you have no real way of knowing if there has been any actual testing done on them at all. At least with Snell, they test the helmets themselves prior to the manufacturer being able to claim Snell approval. They are also a non-profit organisation so less likely to be influenced by financial benefit when evaluating helmets.

The FIM, which sanctions MotoGP races all over the world, accepts any of the above standards but DOT. Why not DOT if DOT helmets are comparable to ECE helmets? Because the DOT is an American institution, and the FIM doesn't really do American. And because the DOT standard doesn't require any outside testing—just the manufacturers' word that their helmets pass.

I'm sure it's because they hate DOT for being American (despite Snell being American) rather than the last sentence.

lol - from the guy who thinks it says "high speed crashes with heavy impacts to the head yet no fatal bodily injuries don't really happen"



what exactly have you "covered"? show me anything you've said that offers better evidence to counter that article and its test results.

fucking lol - you say their research doesn't cover enough situations and types of crashes, then support your opinion with a couple of fucking youtube clips of high-sides. can you hear yourself?


show me one I haven't answered???

Some people in the study, those involved in truly awful, bone-crushing, aorta-popping crashes, did sustain potentially fatal head injuries even though they were wearing helmets. The problem was that they also had, on average, three other injuries that would have killed them if the head injury hadn't.

In other words, a crash violent enough to overwhelm any decent helmet will usually destroy the rest of the body as well. Newman put this into perspective. "In most cases, bottoming [compressing a helmet's EPS completely] is not going to occur except in really violent accidents. And in these kind of cases, one might legitimately wonder whether there is anything you could do."

What a load of shit. So based on 20 and 30 year old street only tests in old helmets where 90% of accidents are low speed, low impact; "one might legitimately wonder whether there is anything you could do"? Great attitude from an expert.



Another thing I found odd was the model name of the Arai helmet they were testing. I'd never heard of it before so I googled it. It's a fucking dirt bike helmet.

Arai Tracker GT Motorcycle Helmets
To you, every turn is a left turn, taken at speed, sideways, sliding, in a near horizontal position, looking for a clear line through a storm of roost. Your handlebars pointing right, your left foot rowing the ground, trying to keep the back end from passing the front end. And you're conducting this symphony with nothing more than a right hand finessing an itchy quarter throttle and a little voice that keeps asking "Is there anymore in there?"

Arai has a new helmet for you.

Our brand new Tracker GT is, as you might have guessed, a dirt-track racing helmet with features designed for the demands of dirt track racing. So if you decide you absolutely need a helmet this unusual for the street, you've been told.

Out of the entire Arai range, that helmet would have to be one of the least suitable for a street helmet test. Way to go publishing it's test results next to out and out sportbike helmets in a test which revolved around bitumen without a mention of it's intended use.

[Rorz de Puniet]

Some of the points that I have raised that you are yet to answer are also raised by Snell themselves in this letter (I have shortened it slightly, it was a little long winded):

Snell Responds:
An Open Letter
May 12, 2005
From: The Snell Memorial Foundation
To: The motorcycling public

I've been several months waiting for the helmet comparison write up that has finally come out as the "Blowing the Lid Off" article in the June issue of Motorcyclist. This same comparison has been done before. During my second year with the Foundation, 1991, some of the same people involved in the current article participated in an effort titled "Breaking Some Eggs." This earlier article also created a stir. They told any number of people that their good helmets were bad. Fortunately, hardly any of them panicked and a sober assessment of the facts indicated that the egg breakers were mistaken. Now, they've done it again. When I hear someone yell "Fire!" in a crowded theater, like most sensible people, I won't stampede for the exits but I'm apt to sniff the air before I start to wonder about who did the yelling. This time, after a little sniffing, I've got to tell you, I'm not smelling smoke. I'm happy to say that the worst is they may have broken the wrong egg again or lifted the wrong lid. In any case, the smell will dissipate quickly so we all can get back to the feature.

The most important item in the article is the helmet comparison itself. They based their comparison on flat impact performance and looked for the lowest peak acceleration. The authors maintain that flat surface impacts are the most common and "Fewer Gs = Less chance of brain injury." Flat impact performance is important, there's no doubt about it but looking at flat impact performance only is like judging a beauty pageant looking through a keyhole. The article holds that more than 75% of impacts will be against a flat surface but this implies that a substantial number of impacts may still be against some other, more threatening surface. The COST 327 report, the same European study mentioned in the article, goes further. It suggests that this number will be much larger than 25% and the resulting hazard much greater than mere flat impact imposes.

The immediate conclusion is: the asphalt slab testing is, at best, incomplete. Impacts against flat surfaces will not tell anyone all they need to know about protective performance. Flat impacts are not the whole story and, if the European data is good, and I've got no reason to doubt it, flat impacts may be the least important crash consideration.

But there's still another weakness, the "fewer Gs = less chance" statement is, at the very least, misleading. All the standards, Snell M2000 and M2005 included, presume a threshold model of injury. That is: so long as a threshold G limit is not exceeded, there will not be a serious injury. A corollary conclusion is that any G exposure not exceeding this G limit is no better or worse than any other G exposure not exceeding this limit. If a G exposure below this limit is safe, another exposure 40 G's lower cannot be any safer.

The difficulty about this threshold is that no one is certain just where it is but there is some confidence about where it isn't. In the 1950's, BSI helmet testing relied on force measurements and used a test criteria that equated to about 450 G in current terms. The first Snell standard in 1959 set a criterion of 400 G but, because the headform was heavier, today's equivalent work out to 435 G. During the 1960's, the Foundation began to lower this G criterion. Snell certified helmets were no longer just for young, tough auto racers. The American public was taking up motorcycling and while many were as tough as anybody on four wheels, many others needed an additional margin of protection. The motorcycling environment itself raised some qualms. Snell standards and helmets were first developed for use in well ordered competition. No one thought the mean streets would require any less than that. If the helmet hadn't already been all the protection the industry could manage, I'm sure Snell would have asked for more. By 1998, the Foundation's criterion settled on 300 G. It was down some 33% from the levels set in England in the 1950's. Why was it down? Likely because the 50's estimates were based on the needs of soldiers and young, healthy males while today's helmets are intended for almost everyone.

What about the Wayne State Curve and all the other advances in the science of head injury during the last fifty years? Much of it was good work by gifted and dedicated scientists but, to this day, no one is quite certain what hammer blows to cadaver skulls and air blasts to the exposed brains of test animals have to say about the risks of helmeted impact. We're all still waiting for the breakthrough that will relate helmet parameters to head injury hazards. Right now, the most directly useful information developed for helmeted impacts has come from crash studies. Those findings suggest that current test criteria are working. If they weren't, COST 327 would not have considered flat impact "the least likely to cause an injury."

The fact is, all the major crash helmet standards call out G figures greater than those in the article. It's 300 G for Snell, BSI 6658, and FIA 8860, the Advanced Helmet Specification set out by FIA in 2004. It's 275 G for ECE 22-05. It's all of 400 G for DOT. Yes, yes, I know they said 250, they said a lot of things. Their rationale is that DOT's "time duration criteria" effectively set a new G limit of 250 rather than the 400 G limit in the standard. This may even be true for flat impact but DOT also calls out impacts against the hemispherical anvil. They even said so in the article. But they did not tell you that the "effective" G limit for the hemi is still 400 G. And, drawing on COST 327, it's there against the shaped hazard anvils like the hemi, the edge or the kerbstone that serious helmets will prove themselves.

The upshot is they seemed to have based their comparison on incomplete tests and drawn their conclusions from inconsequential differences. Anyone who was happy with his helmet before reading this article has been given no real reason to feel any differently now.

Now, ordinarily, at this point we'd fill in the grave, sing a few hymns and go home. But I've got a few more stakes here and the certain feeling we're dealing with the undead. So keep your garlic at the ready because I'm going in again.

The article also takes Snell to task for impact severity. The complaint is that by the time a rider takes that kind of hit, he's dead anyhow. The article proposed to trade that impact management away for softer liners. Yes, it's a trade. We cannot have both. For a given liner thickness, the softer the liner, the lower the energy management. We've been at just about at the limit of acceptable liner thickness for some time. However, there's no real assurance that softer liners would yield any benefit in reduced incidences of fatality or serious injury while, contrary to the article, the COST 327 report concludes that there would be a substantial benefit from increased energy management:

"Head impact energy is proportional to head impact speed, which, in turn, indicates to what extent helmets need to be improved to give a corresponding reduction in injury severity. This was calculated and it was estimated that an increase in helmet energy absorbing characteristics of some 30% would reduce 50% of the AIS 5/6 casualties to AIS 2-4."

There are others who agree. When TRL, one of the companies participating in the COST 327 project, made helmet recommendations to FIA, the controlling body for Formula 1, their advice culminated in FIA 8860, the Advanced Helmet Specification. This specification demands considerably more impact management than the most severe Snell standard. A study of Snell test results has shown that the double impact test against the hemispherical anvil equates, on average, to a single impact of about 185 Joules. FIA 8860 tests helmets against this same hemi anvil and applies a single impact of 225 Joules.

It doesn't take too much imagination to see why this additional impact management might be valuable. When a rider goes off a bike at speed, even if he's got the good fortune to hit smooth pavement with an 8 foot drop or less, his body will still be sliding along the roadway at his initial cruising speed. Since leathers, denim and human skin aren't nearly as effective at braking as a good set of tires, this rider is likely to slide for some considerable distance and every obstacle he encounters offers a considerable head impact hazard. His helmet may have to do considerably more than see him through the first thump. A famous movie star some years ago crashed and received his most serious head injury smacking into a curb after sliding some distance from his bike.

It could be even worse. Frequently, when a rider spills onto the pavement, he will not be able to maintain a controlled slide while his cruising velocity gets scrubbed off. If he gets even a little out of shape he'll start to tumble and sustain multiple strikes to all his extremities. His helmet may need to manage a succession of impacts. And there's also no doubt that if he goes off his bike and strikes something less friendly than flat pavement, for example: a vehicle turning left across his right of way, even that first impact by itself may be considerably more serious than any eight foot drop could ever be.

The article also takes Snell to task for two hits. Snell calls for the helmet to be tested in 150 Joule impact (about 7.75 meters/second) followed by a 110 Joule impact (about 6.6 meters/second) at the same point on the helmet. Snell standards have always been two hits against the flat and hemi anvils and so have DOT and BSI 6658. I've already described how a helmet might sustain more than one hit in a crash and I've seen a number of helmets with signs of several severe impacts and at least a few where those signs overlapped.

Snell certified helmets come in a range of prices, the least expensive cost not much more than Harry Hurt's bargain basement items. Of course, the production costs are higher, Snell test fees and stickers may add a dollar or so but the bulk of the costs is likely to be the internal quality control measures necessary to succeed in the Snell programs. But, if I'm to wear their helmets, I don't want manufacturers going light in this department in any case.

And not everyone wants to shop the bargain basement and I'm not sure that everyone should. There's more to good helmets than protective performance. Riders demanding premiums of comfort, fit quality and good looks may have to move up to the higher shelves. But here again, they can get real value for their money. No one will stay with a helmet that's ugly or uncomfortable, at least, not for very long and a helmet that isn't worn is no bargain no matter how inexpensive.

Snell can't really help with comfort, fit quality or style issues. They're all matters in which riders can tell us much better than we could ever tell them. But I will try to offer a little advice in the matter of fit. The less expensive helmet lines use no more than two helmet configurations to cover the full range of head sizes and some offer just one. A size medium rider is apt to wind up wearing a size x-large helmet stuffed with thick comfort padding to bring it down to his head dimensions. But on the higher shelves, a helmet line might include as many as four or five distinct configurations and at least one manufacturer configures different lines for different head shapes. The result is that almost everyone can find a good fit. The catch is that more configurations imply shorter production runs and, in turn, more expensive production methods. The saving grace is that the value is there, in the helmet. The price reflects the production costs. No one is laying out an extra $30, $40, $60 or $100 dollars for just a Snell sticker. The competition among Snell certified manufacturers is too fierce for that. Riders are getting the protective performance called out in Snell standards and they're getting the comfort, fit and style they demand at the best price our economic system can deliver.


Sincerely,
Snell

Start by answering the points I have raised above and the sections of the letter that are in bold and we'll go from there.

[Billzilla]

From the quote above ...

... I've already described how a helmet might sustain more than one hit in a crash and I've seen a number of helmets with signs of several severe impacts and at least a few where those signs overlapped. ...

You mean exactly like I've been saying over and over again?
Imagine that.

[Norminator]

Exactly, Bill. It's obvious to anyone... come off, roll over, smack your head, roll over, smack your head. Bam... 2 impacts in one place. OMG they said it would never happen! In a car, where range of movement is limited by restraints, I would think it very likely that a helmet could take multiple hits in the same place ie. a head whipping back and forth in a roll-over.

Rorz, the Snell reply is also in the netrider link hrd keeps referring to... maybe he didn't want to read that far down? It is also on the Snell website;

http://smf.org/docs/articles/pdf/btlo_response.pdf

The Snell response covers a lot of the flaws in the article you keep preaching from.

You can lead a horse to water...

[Billzilla]

Exactly, Bill. It's obvious to anyone... come off, roll over, smack your head, roll over, smack your head. Bam... 2 impacts in one place. OMG they said it would never happen! In a car, where range of movement is limited by restraints, I would think it very likely that a helmet could take multiple hits in the same place ie. a head whipping back and forth in a roll-over.

Those are the ones that worry me. Fair enough they're probably not going to be super-hard hits but again you don't know that for sure. The cage should have soft padding on it as well and that helps quite a lot.

I have wondered what the ride was like for the guy that hit me last year - He slid for over a hundred metres inverted and our cars don't have a roof of course so his helmet may well have been dragging on the road for most of that.

[Rorz de Puniet]

To talk about helmet design and performance with any measure of authority, we should first look at the kinds of accidents that actually occur. The Hurt Report, issued in '81, was the first, last and only serious study on real motorcycle accidents in the U.S. The study was done by some very smart, very reputable scientists and researchers at the University of Southern California. The Hurt researchers came to some surprising and illuminating conclusions—conclusions that have not been seriously challenged since.

Sounds like they are putting an awful lot of weight into that Hurt report. The information used in the Hurt report was actually gathered in 1976/77, it was compiled in 1981 meaning the data is actually 35 odd years old. The sportbike class hadn't even been invented yet and to be fair, the bikes of the day were quite slow and handled like a wheel barrow with a flat tyre. Harry Hurt actually died in 2009 at age 81.

Here's a picture of a helmet from that era:



Why they would even reference a study that old is beyond me let alone elude to the fact it is a superior study to any that have been done since.

The killer—the hardest Snell test for a motorcycle helmet to meet—is a two-strike test onto a hemispherical chunk of stainless steel about the size of an orange. The first hit is at an energy of 150 joules, which translates to dropping a 5-kilo weight about 10 feet—an extremely high-energy impact. The next hit, on the same spot, is set at 110 joules, or about an 8-foot drop. To pass, the helmet is not allowed to transmit more than 300 Gs to the headform in either hit.

Tough tests such as this have driven helmet development over the years. But do they have any practical application on the street, where a hit as hard as the hardest single Snell impact may only happen in 1 percent of actual accidents? And where an impact as severe as the two-drop hemi test happens just short of never?

Dr. Jim Newman, an actual rocket scientist and highly respected head-impact expert—he was once a Snell Foundation director—puts it this way: "If you want to create a realistic helmet standard, you don't go bashing helmets onto hemispherical steel balls. And you certainly don't do it twice.

"Over the last 30 years," continues Newman, "we've come to the realization that people falling off motorcycles hardly ever, ever hit their head in the same place twice. So we have helmets that are designed to withstand two hits at the same site. But in doing so, we have severely, severely compromised their ability to take one hit and absorb energy properly.

Even if you ignore the part of the Snell letter which explains exactly how multiple strikes to the same area can and do occur, there is a major problem with the section I have put in bold. He states that Snell approved helmets have a severely, severely compromised ability to take one hit and absorb it properly. Yet in the tests, even the Arai dirt bike helmet passes all it's single impact tests with less than 250G's. Then you have the slight problem that Snell actually requires less G's to be transferred during testing than most other standards.

The Snell approved Icon scores:

Icon Alliance (F)
# Average: 183 Gs
# LF: 179 gs
# RF: 200 gs
# LR: 179 gs
# RR: 175 gs

So what the fuck is he basing that statement on exactly?

[hrd]

guess I'll start with the first part you bolded for emphasis as if it's some sort of good point...
[quote]But there's still another weakness, the "fewer Gs = less chance" statement is, at the very least, misleading. All the standards, Snell M2000 and M2005 included, presume a threshold model of injury. That is: so long as a threshold G limit is not exceeded, there will not be a serious injury. A corollary conclusion is that any G exposure not exceeding this G limit is no better or worse than any other G exposure not exceeding this limit. If a G exposure below this limit is safe, another exposure 40 G's lower cannot be any safer.[//quote]

I don't really know why I'm bothering to explain this, it was all in the report. If you didn't get it then, you're no more likely to now. But here goes.

That presumed injury threshold Snell uses is 300G; ""The whole business of testing helmets is based on the assumption that there is a threshold of injury," says Ed Becker, executive director of the Snell Foundation. "And that impact shocks below that threshold are going to be non-injurious. "We're going with 300 Gs... The basis for the 300 G [limit in the Snell M2000 standard] is that the foundation is conservative. [The directors] have not seen an indication that a [head injury] threshold is below 300 Gs. If and when they do, they'll certainly take it into account."

Cost327 Report; "Fatal injuries are estimated to have occurred at 200g and above which is consistent with Newman (1986) who suggested that 200g-250g corresponds to AIS4, 250g-300g to AIS5 and greater that 300g to AIS6."
AIS4 is severe head injury. AIS5 is critical injury. According to Cost327, 75% of accidents with an AIS5 and above injury are fatalities.

So much for Snell's position that "any G exposure not exceeding this G limit is no better or worse than any other G exposure not exceeding this limit. If a G exposure below this limit is safe, another exposure 40 G's lower cannot be any safer"

That's a fucking scary position for a company that's purporting to be the pinacle of helmet safety standards!

Is there really any reason to bother with their other counter arguments, like trying to discredit the Wayne State Tolerance Curve and the JARI Human Head Impact Tolerance Curve without offering any facts is also a scary thing to hear from a group who are supposedly protecting heads from injury.

self-professed experts with no facts/data vs actual scientific studies and the medical profession who both have evidence-based positions. Hmm, who to trust...

[Rorz de Puniet]

guess I'll start with the first part you bolded for emphasis as if it's some sort of good point...

But there's still another weakness, the "fewer Gs = less chance" statement is, at the very least, misleading. All the standards, Snell M2000 and M2005 included, presume a threshold model of injury. That is: so long as a threshold G limit is not exceeded, there will not be a serious injury. A corollary conclusion is that any G exposure not exceeding this G limit is no better or worse than any other G exposure not exceeding this limit. If a G exposure below this limit is safe, another exposure 40 G's lower cannot be any safer.[//quote]

I don't really know why I'm bothering to explain this, it was all in the report. If you didn't get it then, you're no more likely to now. But here goes.

That presumed injury threshold Snell uses is 300G; ""The whole business of testing helmets is based on the assumption that there is a threshold of injury," says Ed Becker, executive director of the Snell Foundation. "And that impact shocks below that threshold are going to be non-injurious. "We're going with 300 Gs... The basis for the 300 G [limit in the Snell M2000 standard] is that the foundation is conservative. [The directors] have not seen an indication that a [head injury] threshold is below 300 Gs. If and when they do, they'll certainly take it into account."

Cost327 Report; "Fatal injuries are estimated to have occurred at 200g and above which is consistent with Newman (1986) who suggested that 200g-250g corresponds to AIS4, 250g-300g to AIS5 and greater that 300g to AIS6."
AIS4 is severe head injury. AIS5 is critical injury. According to Cost327, 75% of accidents with an AIS5 and above injury are fatalities.

So much for Snell's position that "any G exposure not exceeding this G limit is no better or worse than any other G exposure not exceeding this limit. If a G exposure below this limit is safe, another exposure 40 G's lower cannot be any safer"

That's a fucking scary position for a company that's purporting to be the pinacle of helmet safety standards!

Is there really any reason to bother with their other counter arguments, like trying to discredit the Wayne State Tolerance Curve and the JARI Human Head Impact Tolerance Curve without offering any facts is also a scary thing to hear from a group who are supposedly protecting heads from injury.

self-professed experts with no facts/data vs actual scientific studies and the medical profession who both have evidence-based positions. Hmm, who to trust...

Your argument is based on the fact that in the article they claim that Snell has higher allowable G limits than DOT. The thing is, that is totally incorrect as Snell has considerably lower allowable G exposure than DOT standards which leaves that argument in tatters. You're arguing that you want less G's transferred to the head while supporting a standard which allows the exact opposite.

What about the Wayne State Curve and all the other advances in the science of head injury during the last fifty years? Much of it was good work by gifted and dedicated scientists but, to this day, no one is quite certain what hammer blows to cadaver skulls and air blasts to the exposed brains of test animals have to say about the risks of helmeted impact. We're all still waiting for the breakthrough that will relate helmet parameters to head injury hazards. Right now, the most directly useful information developed for helmeted impacts has come from crash studies. Those findings suggest that current test criteria are working. If they weren't, COST 327 would not have considered flat impact "the least likely to cause an injury."

So you're saying my Youtube videos of guys crashing in modern helmets are irrelevant yet you're happy to rely on conclusions drawn from some experiments which involved bashing animals over the head with a hammer (which have a different skull to humans and aren't wearing a helmet) and removing sections of dogs skulls then blasting their brain with compressed air. Sure okay.

They are also referencing the COST 327 report but that report seems to have an almost opposite view to some of the opinions they are trying to express. The article considers flat impact the most likely to cause serious injury yet the COST 327 report considers it the least likely to cause serious injury.

The fact is, all the major crash helmet standards call out G figures greater than those in the article. It's 300 G for Snell, BSI 6658, and FIA 8860, the Advanced Helmet Specification set out by FIA in 2004. It's 275 G for ECE 22-05. It's all of 400 G for DOT. Yes, yes, I know they said 250, they said a lot of things. Their rationale is that DOT's "time duration criteria" effectively set a new G limit of 250 rather than the 400 G limit in the standard. This may even be true for flat impact but DOT also calls out impacts against the hemispherical anvil. They even said so in the article. But they did not tell you that the "effective" G limit for the hemi is still 400 G. And, drawing on COST 327, it's there against the shaped hazard anvils like the hemi, the edge or the kerbstone that serious helmets will prove themselves.

Then you have:

The two tolerance curves agree on how many Gs you can apply to a human head for how long before a concussion or other more serious brain injury occurs. And the Wayne State Tolerance Curve was instrumental in creating the DOT helmet standard, with its relatively low G-force allowance.

According to both these curves, exposing a human head to a force over 200 Gs for more than 2 milliseconds is what medical experts refer to as "bad." Heads are different, of course. Young, strong people can take more Gs than old, weak people. Some prizefighters can take huge hits again and again and not seem to suffer any ill effects other than a tendency to sell hamburger cookers on late-night TV. And the impacts a particular head has undergone in the past may make that head more susceptible to injury.

Is an impact over the theoretical 200 G/2 millisecond threshold going to kill you? Probably not. Is it going to hurt you? Depends on you, and how much over that threshold your particular hit happens to be. But head injuries short of death are no joke. Five million Americans suffer from disabilities from what's called Traumatic Brain Injury—getting hit too hard on the head. That's disabilities, meaning they ain't the same as they used to be.

The DOT standard has relatively low G-force allowance? Compared to what? Certainly not Snell as we have already established the DOT G-force allowance is higher. Last sentence is interesting. So although Newman is suggesting 200-250G's corresponds to a serious head injury it has been proven that level of G force may do nothing at all.

The COST 327 study investigated 253 motorcycle accidents in Finland, Germany and the United Kingdom, from '95-'98. Of these, the investigators selected 20 well-documented crashes and replicated the impact from those crashes by doing drop tests on identical helmets in the lab until they got the same helmet damage. This allowed them to find out how hard the helmet in the accident had been hit, and to correlate the impact with the injuries actually suffered by the rider or passenger. The COST 327 results showed that some very serious and potentially fatal head injuries can occur at impact levels that stiffer current helmet standards—such as Snell M2000 and M2005—allow helmets to exceed.

Again, they are drawing conclusions from the COST 327 study using the basis that Snell allows higher G's than DOT which is a lie. It seems odd that people that actually participated in the COST 327 project draw entirely different conclusions from it than the article:

When TRL, one of the companies participating in the COST 327 project, made helmet recommendations to FIA, the controlling body for Formula 1, their advice culminated in FIA 8860, the Advanced Helmet Specification. This specification demands considerably more impact management than the most severe Snell standard. A study of Snell test results has shown that the double impact test against the hemispherical anvil equates, on average, to a single impact of about 185 Joules. FIA 8860 tests helmets against this same hemi anvil and applies a single impact of 225 Joules.

So participants of the same project they are referencing to support their argument for softer helmets have made recommendations for even harder helmets.





I think we've comprehensively covered the G force thing, please now address the other valid points that have been raised.

[hrd]

if you think that comprehensively covers the G force thing, you're mistaken.

my argument in the last post is based on Snell saying anything below 300G is perfectly fine, vs the medical profession's AIS and other scientific studies. It goes to the core of Snell's methodology and principals; they say anything under 300G to the head is perfectly fine, when in fact it can kill you or give you critical injuries. The fact they openly riducule scientific research into brain injuries without any reasons or better evidence, is an appaling position for a body purportedly interested in creating standards for protecting the head.

Pretty sure the Wayne State Tolerance Curve study is a bit more involved than your idiotic description of it, but yes I think that research is better evidence of brain injury thresholds than your fucking pointless you-tube clips. Research and empirical testing > youtube and conclusions drawn by some muppet watching on his computer based on his own assumptions.

And your last quote comprehensively covering the 'G force thing' doesn't even mention G's... Its arguing for better energy management in higher joule tests. That means less G's transferred to the head in high energy impacts.

[Rorz de Puniet]

if you think that comprehensively covers the G force thing, you're mistaken.

my argument in the last post is based on Snell saying anything below 300G is perfectly fine, vs the medical profession's AIS and other scientific studies.

You're totally ignoring the fact that the article clearly says that more than 200G's is too much yet they support DOT as a superior standard which allows 400G's. Retarded.

Pretty sure the Wayne State Tolerance Curve study is a bit more involved than your idiotic description of it, but yes I think that research is better evidence of brain injury thresholds than your fucking pointless you-tube clips. Research and empirical testing > youtube and conclusions drawn by some muppet watching on his computer based on his own assumptions.

And your last quote comprehensively covering the 'G force thing' doesn't even mention G's... Its arguing for better energy management in higher joule tests. That means less G's transferred to the head in high energy impacts.

It's not "some muppet watching his computer" drawing his own conclusions. They are the conclusions of the most highly respected independant helmet testing organisation in the world.

It wasn't the last quote which comprehensively covers the "G force thing", it's the last 3 posts. Stop ignoring the fact they have got the allowable G force figures for the different testing organisations totally wrong!