Helmet Article in May Motorcyclist Mag

[Jim Crenca]

There is a lenghtly article that includes testing of helmets in the May issue of Motorcyclist magazine. The short version is that DoT thermoplastic helmets may be safer than SNELL approved helmets as they don't transfer as much energy to the brain upon impact. The article includes a modified test plan that uses apshalt against the helmet as opposed to a chunk of steel, and, they use a single impact instead of the 2 impacts that SNELL uses. The above is a hugely condensed version of the article but, ther numbers indicated that a $100 DoT helmet transfered much less energy than a $400 Arai during independant testing.

Anybody have any insight on this one? :bang:

 

[CaptainObvious]

I too saw that article a few weeks ago. I read it a few times. From now on, DoT will do fine for me, thank you very much. I always suspected that the high priced helmets were just that.

Besides I don't mind throwing a $150 helmet away after a crash, but I'd hate to have to part with $400 for a helmet that, in the end, might do me more harm than good.

 

[tnrider]

that is why i buy my arai helmets at discount - since i only pay about $150 for them, i should get double the coverage...

what is interesteing is that i believe that steel is harder than asphault - of course, i would rather not hit either.

there is also nothing that prevents a mfg - especially a foreign one - from putting any sticker on their "knockoff" helmet. i have even seen dot/snell stickers at the local dealer for the cruser guys to put on their little helmet shells.

 

[bikepilot]

I have not read the article, but dissagree with the condensed version above. Granted, my testing is mostly ancidotal and non-scientific, but its convincing enough to me that I absolutely will not wear a dot thermoplastic helmet.

here's my reasoning.

Hypothesis: Thermoplastic helmets bounce, transfering tremondous energy to a riders head. My evidence,
A. a frind of mine bought one agains my advice went down in what looked like a mild crash about mid-rpm 3rd gear on a 91 YZ125 (with +2 on the rear sprocket). He suffered 3 broken bones in the right side of his face and had to have $30k worth of Ti plates and reconstructive surgery to look normal again. His face did not hit the ground, just the inside of his dot polycarb helmet. I have been riding for 10 years, have crashed very hard many times. The worst I'v suffered was a concussion in a very bad crash involving a tripple gone wrong.

B. I had a dot polycarb helment that came with a bike I bought, I also had a retired Fox Pilot Snell CF/Fiberglas helmet. I decided to test them both. I droped both from the same height onto my concret driveway. The Dot helmet bounced about 3ft, the Snell helmet bounced about 6 inches. Ok, so what about a harder impact? I threw them both at the driveway at roughly the same speed, the DOT helmet bounced aproximatly 12+feet (way over my head, no good way to measure very exactly), the Snell helmet about 1.5 feet. Tried it again, this time throwing them down as hard as I could, the DOT helmet performed like a rubber bouncy ball and shot very high, the snell helmet didn't make it up to my waist.

I'm sticking with my Arai.

Captian - any way you can share that great Arai deal?

 

[njkx]

as far as i know you can buy a bunch of helmets in the $150-200 range that are DOT and SNELL tested and are made out of the same material as Arai. Not saying that they are as good but i'm not sure that they aren't.

 

[CaptainObvious]

The point of the article is that DOT and SNELL differ on what they deem to be an acceptable maximum limit of force (expressed as units of gravity, a/k/a “g’s”).

DOT has set their limit at 200 g’s before the inner structure (usually made from EPS) of the helmet deforms. SNELL’s limit is 250 g’s (please keep in mind that I saw this article 2 weeks ago and I’m quoting from memory). The DOT limit represents the “90th percentile” impact.

While at first looking at these limits you’d make the conclusion that the higher the limit the better, but the opposite is true. For a given impact and acceleration, the DOT certified helmets do not allow a force in excess of 200 g’s. The SNELL limit is 250 g’s. In looking at a statistical body of crash information, Motorcyclist and their consultant (Mr. Harry Hurt from the famous Hurt Report on Motorcycle Accidents: Cause Factors and Identification of Countermeasure) feel that an impact in excess of 200 ‘g is unsurvivable. So, in short, helmets that are SNELL certified impart far too many g’s to a human skull.

The best performing helmet in the test (all street helmets, but the conclusions are equally valid to off-road helmets) was a $90 ZR1 helmet with a polycarbonate shell. The poorest performing helmets were the ones with a composite-resin shell (Arai comes to mind). If my memory is correct, the ZR1 sustained a max average load of 170 g’s while the Arai allowed 250 g’s from the same drop(s). That is a life and death difference.

The article is worth a read. There is a lot of good information on how the brain reacts to a high g impact.

 

[XRpredator]

so from what I gather, in laymen's terms:

The helmet may survive, but your melon won't

 

[Jim Crenca]

Other factors include that the SNELL test requires 2 impacts where as DoT has one. The article has some really great statistics and tech info that suggest that:
* A small percentage of riders die going way fast
* Most accidents are close to home and occur at about the speed limit
* The chance of serious injury greatly increases with the number of things that get hurt; for example you can survive a much larger head injury if you don't also have leg, arm, stomach injury / trauma.
* A very few percent of accidents have more than 1 serious blow to the head (making the SNELL sound like too tight a spec)
* In order to meet SNELL, the outer shell has to be very tough and may not help the helmet system absorb shock; generally the plastic shells did much better than composites in regards to working with the softer inner foam in shock absorption
* You don't have to be Einstein to know that absorbing shock is super important in helmet design
* Abrasion and puncture resistance did not seem to be a problem with either testing standard
* One manufacturer commented that meeting the highest safety standard is a must for his marketing campaign
* The European standards are closer to DoT than to SNELL
* If these guys are right, the helmet industry is going to be in store for a big shake up

 

[moore_716]

I totalled my cbr900rr at around 120mph into a tree head on with a shoei helmet on. I took a huge chunk out of the tree and even left part of the scott russell graphics embedded in it. Most of the clear exterior coating shattered like glass, but the helmet survived. Me to, although I don't remember the next week. I know that a walmart helmet wouldn't have saved my life. As far as I know Snell helmets were supposed to be better at absorbing impacts from faster speeds and harder impacts. DOT helmets work better in the slow stuff. Just what I've always been told.

 

[JTT]

so from what I gather, in laymen's terms:

The helmet may survive, but your melon won't

Actually Pred, quite the opposite. I haven't been able to sit down and thoroughly read through the article yet, as I was shown it by a freind and only had time for a quick read through so bare with me. It would seem that this "independant" testing showed repeatedly that survivability of the users in some of these DOT and ECE helmets was actually better than those of the SNELL approved ones, particularly when we're speaking of "average" folks, not professional atheletes (like us Pred ;) )

 

[XRpredator]

. . . "independant" testing showed repeatedly that survivability of the users in some of these DOT and ECE helmets was actually better than those of the SNELL approved ones, . . .

This is what I gathered. While the SNELL approved helmets may take a larger impact, the melon inside may not be able to withstand it. At least that's what this cat reads into it.

 

[Jim Crenca]

Rich R.,
Do you have any tech. toughts on this one?

 

[bikepilot]

Also, keep in mind that Hurt had a large part in this article. He is far from an indpendant, objective source. Just look as his stuff that was published in MCN a few months ago and the response from the Snell folks that followed in the next issue. Its an interesting and importaint topic, but as long as I'm betting with my life, my head will be in a Snell approvoved composite shelled helmet, usualy an Arai, though I do have a Shoie and M2R.

Stay Safe:thumb

 

[CaptainObvious]

Sorry for the double post, but this debate has morphed into two threads...

You are wrong. And you are completely unaware of NHTSA FMVSS218 requirements. A copy of the test can be found HERE.

The drop test is conducted from a height of 54.5 to 72 inches and the headform is accelerated to a speed of approximately 19 ft./sec, or 13 mph. Mind you, whether you are riding at 15 mph or 150 mph, it should not impact the speed at which your head falls to the ground. Now, if think you are buying a helmet to withstand a direct impact to a stationary object, say a wall or tree, good luck finding that helmet because no one builds a helmet for that impact. In fact, your neck would surely break before your brain compresses into your skull.

The purpose of the test is to simulate real world conditions for the 80th percentile event. What good would it be to design a test for a 60 mph impact? You would not survive anyway.

Regarding Mr. Hurt, he is the leading expert on motorcycle crashes and helmet safety. I surly value his opinion over your anecdotal story! Your story about throwing a helmet is hardly scientific. It isn’t even repeatable. Please, by all means, wear the helmet that you are most comfortable in. But do not recommend it based on your junk science.

 

[gwcrim]

I know that a walmart helmet wouldn't have saved my life.

How do you know that, for sure?

 

[CaptainObvious]

For those who didn't see the original article but are interested in seeing it, Motorcyclist has now posted it online...

http://motorcyclistonline.com/gearbox/hatz/

 

[hoosierf]

FWIW, this is an old debate that I first remember reading in the late '80's. In the original discussion, the conclusion was that the requirements for dirt riding helmets and street riding were quite different and that all of the tests were focused on street bike type impacts. The conclusion was that offroaders were better off in DOT helmets. I wear an Arai and I just bought a Shoei to paint this winter; I'd forgotten all about this discussion. If I had it to do over, I'd re-think my purchase.

 

[tx246]

ive subscribe to the softer is better theory. the high end helmets are nice as far as fit and finish but basically have the same thing between the liner and exterior. its called styrofoam. this is what decellerates your skull. how many times has your helmet hit the ground (with or without your head in it)?

MY GREATEST FEAR IS THAT PEOPLE WITH HIGH END HELMETS HESITATE TO THROW AWAY THEIR HELMET WHEN IT NEEDS TO BE.

everybody go check your helmet. its easy. remove the liner and the styro is right there. lots of times it is painted black and anything damaged will show right up. ive had low side crashes that were nothing but my head hit the ground and the result seriously comprimised the liner. the liner did its job and i throw the $125 helmet away and get another without batting an eye.

 

[notenuftoys]

I used to ride road and mountain bikes, and it is commonly recommended that if you crash and impact your helmet hard, get a new one. Anytime the helmet is impacted, it's compromised in some way. Of course, bike helmets are only $50-$90, so it's easier to toss them.

Bottom line, wear a helmet! I think for most of our riding, on or off road, our melons won't survive an impact without some sort of serious injury. And we only get one brain (whether it works or not, I won't comment). It drives me crazy seeing these lazy Harley riders with no helmets; they are generally mid-lifers trying to be cool. Well, it ain't too cool when the melon impacts asphalt.

Just my $.02...

 

[robwbright]

I know its not the BEST brand, but I got a SNELL rated M2R helmet for $67 plus shipping.

Rob