Helmets 101


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Helmets 101

Post by WingAdmin » Sun Feb 25, 2018 10:34 pm



Full face. Open face. Flip-up. Brain bucket. Motocross. Fiberglass. Polycarbonate. Carbon Fiber. Kevlar. Snell. DOT. ECE. EPS. So many options when selecting a helmet, how do you start when trying to select something that is going to protect the most vital part of your body?

Let's start with what's common amongst all motorcycle helmets: the construction.

Typical helmet construction
Typical helmet construction

There are three main parts to a motorcycle helmet:

Outer shell, usually polycarbonate, fiberglass, carbon fiber, Kevlar or a combination of those
EPS (Expanded Polystyrene) foam layer
Comfort liner – the inner fabric and padding that sits against your head and face

Outer Shell

The helmet has two jobs: protecting your head from impact forces, and reducing the instantaneous energy being transmitted to your brain during impact.

The job of the outer shell is to prevent penetration during impact, and to distribute the impact over a much larger area. It does this by being relatively stiff. Impact in one area is spread over a larger area by the stiff shell. It might give up its life in doing so, but cracking the shell of your helmet is a far better option than cracking the shell of your head.

The outer shell is the real differentiator between modern helmets. Inexpensive helmets with a polycarbonate shell can be had for under $100, although you will be giving up a lot of features at that price point. An example of a decent quality inexpensive polycarbonate helmet manufacturer is HJC. These helmets are normally made in a plastic injection mold.

Fiberglass is the traditional outer shell material for helmets, made up of layers of glass fiber strands embedded in resin. Extremely strong and stiff, fiberglass is still used in a large number of quality helmets, including Shoei and Arai.

Carbon Fiber and Kevlar are newer, extremely strong and lightweight materials, used on the most expensive helmets - you likely will not find a carbon fiber or kevlar helmet for under a $1000. They are much more able to prevent penetration or splitting upon impact.

One of the benefits of fiberglass, carbon fiber and kevlar is that they are all made of strands of fiber laid up in epoxy, and they can delaminate and pull apart upon impact. This takes energy to do, which means some of the energy which would otherwise be used to jostle your brain around in your head is instead being used to rip apart the construction of your helmet. Dissipating energy is the name of the game when it comes to helmets.

EPS Layer

The EPS layer is the energy absorption layer. EPS is expanded polystyrene - more commonly known as styrofoam. In your helmet, it is engineered to crush - and not rebound. Why? It's all about reducing that energy spike. When you hit your head against something hard, your head goes from moving at say 10 mph to 0 mph in an instant. That puts a massive deceleration spike - a ton of energy - into your head, which jostles your brain and can rip blood vessels in your cranium. How helmets help with this is by slowing this spike down, and spreading out the deceleration over a longer period of time.

Instead of your head moving from 10 mph to 0 in an instant, it takes maybe 1/10 of a second. It doesn't sound like much, but in the world of energy dissipation, it's a huge amount. The way we spread this out is by using the EPS layer. The shell of the helmet hits the obstacle, and it comes to a stop instantly. Your head keeps moving inside the helmet, crushing the EPS layer as it does, slowing down from 10 mph to 0 as the EPS is smashed down.

The thickness and composition of the EPS layer makes a big difference. A thicker EPS layer means your head can take longer to slow down, which means the helmet will protect your head better during a crash.

EPS does not re-expand or rebound after it is crushed - which is why it is important to remember that once a helmet has been in a crash, it is scrap: it has lost its protective qualities, and will no longer protect your head in a crash. Most helmet manufacturers coat the inside of the EPS layer with a thin layer of paint. If the EPS has suffered an impact, the paint will be broken, and the white EPS layer underneath will show through - indicating that the EPS layer has been crushed, and that the helmet should be replaced.

New EPS Liner with paint intact
New EPS Liner with paint intact


Old EPS Liner with paint cracked and worn away
Old EPS Liner with paint cracked and worn away


Helmet EPS Liner showing impact damage
Helmet EPS Liner showing impact damage

There are new helmet designs with a third layer, between the shell and the EPS layer. This layer consists of small, rubbery discs that allow the EPS layer to rotate slightly within the shell. The aim is to prevent rotational injury from sudden rotation of the helmet (i.e. when you strike the ground while still traveling quickly, and your helmet is quickly jerked around). These helmets are currently priced in the stratosphere, but I suspect we will be seeing more and more of them in the near future.

"6D" helmet offers torsional impact protection
"6D" helmet offers torsional impact protection

Comfort Liner

The comfort liner does two things: it makes the helmet comfortable on your head, and it keeps the helmet snug so that it doesn't move and cannot be ripped off your head. Many better helmets have removable comfort liners that can be removed and washed, which is nice - helmets worn in hot sunny (i.e. sweaty) weather can start to smell! Some manufacturers such as Arai have different thickness parts of their comfort liners available, to make the helmet fit exactly to YOUR head.

Certification

If you live and ride in the US or Canada, you can look at the back of your helmet and find a sticker that says:

Helmet model
DOT
FMVSS No. 218
Certified

If your helmet has this, congratulations, you are the owner of a street-legal helmet that is approved by the DOT for on-road use. If it doesn't...then your helmet is not certified safe, and you can actually be given a ticket if you are riding somewhere where helmets are mandatory. There are many "decorative" brain-bucket type helmets popular with Harley riders that are not certified, and actually offer little to no protection.

You might see other certifications as well. More expensive helmets will also be Snell certified. Snell certifications are more rigorous than DOT: Snell certified helmets must be able to survive two impacts in the same place (and still provide protection during both impacts), and Snell also requires impact testing on the chin bar, which DOT does not. This is important: over 80% of motorcycle crashes have the primary impact on the face. There are many polycarbonate helmets that completely fail this test, the chin bar collapsing in and smashing the rider's face. Of course, if you are wearing an open-faced helmet, this is not a problem, as your face will be taking the initial impact 80% of the time instead of the helmet. Are you sure you don't want a full-face helmet?

The ECE 22.05 regulation, seen on more and more DOT helmets all the time, is the accepted standard in Europe as well as other countries such as Japan and Australia. The ECE regulation covers the rider's field of vision and hearing, head coverage, vents and other projections that stick up from the shell, material durability, heat, cold, moisture, chinstraps and flammability, in addition to protection, labeling and helmet weight (mass). The ECE has three different certification levels:

“J” if it doesn’t have a chinbar (open-face helmet)
“P” if it has a chinbar that is certified as protective
“NP” if it has a chinbar that is not certified as protective

Many standards are continually updated and improved, and you will see this in the helmet. For instance, on Snell-certified helmets, you will see a Snell certification sticker: M2005, M2010, M2015, depending to which standard the helmet was certified. If the helmet is new, it should be a M2015!

Picking a Helmet

To start, you need to set a budget, and then start investigating helmets that fit in your budget. I would highly recommend buying the best helmet you can afford, that fits the best you can find. Fit is extremely important - too large a helmet will rotate on your head and can be ripped off in a crash, too small a helmet will cause "hot spots" on your head and make your ride a miserable experience. Different helmet manufacturers make different shapes of helmet, so you might find that Bell helmets don't fit your head well at all, but Shoei helmets do. Arai is the only manufacturer that makes different shaped helmets: they have three different shapes from which you can choose. I have a long, oddly-shaped head, and Arai's "long oval" shape helmets are the only helmets I have ever found that fit me comfortably. I'd recommend going to a motorcycle store (or better yet - a show) and try on several helmets until you come across one that fits well and feels good. If the store will allow it, try wearing it around for half an hour, to make sure that it doesn't cause any hot spots.

Of course, you first need to know what type of helmet you want:

- Full face: My preference, gives you the most protection.
- Modular (flip-up): Works like a full-face, but can be lifted to open up and perform like an open face
- Open face (¾ helmet): Protects the back, tops and sides of your head, but leaves your face unprotected
- Half helmet (Harley brain bucket): Protects the top of your head, and not much else
- Off-road (motocross helmet): Usually not legal for road use
- Dual-sport (crossover, ADV, hybrid, enduro): Looks like a motocross helmet with an extended chin bar, but intended for road use

My preference is the full-face, and I prefer Arai helmets for the same reason that I don't care for modular helmets: most full-face helmets (and all modular helmets) have pods for the chin bar (modular) or visor hinge (full-face) that intrude into the helmet, giving you less room for the EPS in the critical temple area. You want as much EPS as possible there! Arai differs by mounting its hinge on the outside of the shell, to give the interior the most EPS material possible.

You will find that as you pay more, you get more comfort features - vents, curtains, etc. - but also more safety features. Most high-end helmets have emergency removable padding:

Emergency release tabs
Emergency release tabs

These tabs are used by emergency personnel after a crash. Pulling on them ejects the lower padding from the helmet - the padding that normally grips your face. This opens up the bottom of the helmet, so that it can be pulled from your head easier, without risking damage to your spinal cord should you have suffered a neck injury.

Replacing a Helmet

Helmet manufacturers universally recommend replacing a helmet after five years of service. Most regular riders will be in need of a new helmet by this point. EPS liners degrade with exposure to common everyday things - ozone, gasoline fumes, heat, moisture - and after five years, their effectiveness as a protective layer is no longer what it was when the helmet was new. Manufacturers and regulatory testing agencies continually come up with improvements - so your five-year-old helmet will not have the benefit of those improvements.

Helmets, unlike tires, do not start aging at the moment of manufacture: a three-year old helmet that has sat on the store shelf is considered brand new when you buy it, and should be good for another five years.

Visors

Visors are typically made of high-strength polycarbonate, and can take direct impacts without shattering. Higher-end helmets allow for "pinlock" inserts, which are plastic sealed layers that fit to the inside of the visor. This insert will prevent the helmet visor from fogging up from your warm breath on a cold day, and are highly worth the cost. Some helmets have the facility to allow the visor to be "cracked" open slightly, for ventilation purposes. And speaking of ventilation, higher priced helmets do give you features like closable vents, lower noise, and chin curtains (a cover for the chin area that seals out cold air on cooler days).

Hopefully this has covered some of the basics of helmet construction and features. I'd encourage you to comment with your experiences or any questions you might have!



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Re: Helmets 101

Post by Alan_Hepburn » Mon Feb 26, 2018 7:19 pm

Great information! Too many people seem to think that those brain buckets preferred by a certain demographic are good enough to protect their brain!
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Re: Helmets 101

Post by DaveO430 » Mon Feb 26, 2018 8:17 pm

Good article. I have an ECE-R certified helmet, your article doesn't cover the "R" so I found this;

ECE R22-05 – Developed by the rather lengthily named United Nations Economic Commission for Europe, this is the most common helmet certification internationally, required by over 50 countries worldwide. It is approved for all competition events by AMA, WERA, FIM, CCS, Formula USA and the big one – MotoGP. It, much like the DOT standard, favours a more impact-absorbent helmet allowing a maximum of 275g’s (the ECE R22-05 anvil is either flat or “kerb shaped” depending on the test). The ECE R22-05 is arguably the most up-to-date helmet certification standard, it’s wide use in a variety of high-level motorcycle racing classes is reassuring to many. The ECE R22-05 has more in common with the DOT standard than either the Snell M2005 or M2010 standard, an ECE R22-05 certified helmet are likely to pass the DOT test and vice-versa.

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Re: Helmets 101

Post by SlowTyper » Thu Mar 01, 2018 3:02 am

Isn't Brain Bucket an oxymoron?

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Re: Helmets 101

Post by there707 » Thu Mar 01, 2018 10:36 am

Great article, I knew the majority of it but is was a great refresher.
My understanding is that only Snell has a test for chin bars so either DOT or ECE approved modular or flip-up helmets may actually have an inferior hinge mechanism that could fail if the helmet receives a frontal (chin bar) hit. Is anyone able to confirm this?

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Re: Helmets 101

Post by WingAdmin » Thu Mar 01, 2018 11:12 am

there707 wrote:
Thu Mar 01, 2018 10:36 am
Great article, I knew the majority of it but is was a great refresher.
My understanding is that only Snell has a test for chin bars so either DOT or ECE approved modular or flip-up helmets may actually have an inferior hinge mechanism that could fail if the helmet receives a frontal (chin bar) hit. Is anyone able to confirm this?
From the Snell M2015 standard:
There are two varieties of full face helmets. The chin guard may be an integral, immovable part of the helmet but, in so-called “modular” or “flip-up” helmets the chin guard may be hinged so that, when released, it will pivot or flip up and out of the way for the rider’s convenience. Modular helmets must meet all the same requirements as those equipped with integral chin bars with the additional requirement that the chin guard release mechanism must be sufficiently secure to prevent inadvertent opening in a crash impact.
A similar standard was in Snell M2010. I believe there was one modular helmet in 2013 that met M2010, I'm not sure that there are any that meet M2015. The fact that the vast majority of modular helmets (I struggled to find even one) are NOT Snell approved, says something right there.

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Re: Helmets 101

Post by Rednaxs60 » Thu Mar 01, 2018 1:27 pm

I prefer a modular helmet, like the flip-up aspect. These helmets are not Snell certified because of the flip-up aspect - have not found information other than this, and hard to find a modular helmet that would meet the Snell standard(s). ECE certification for these helmets is achieved primarily because of the locking mechanism that is aluminum or metal, not plastic. DOT certified modular helmets locking mechanism does not have to be metal/aluminum.

I think when it comes to the brain and what the damage can do your lifestyle, a modular is the second best option if a full face non-modular helmet is not your preference. On the advanced rider course I take, the instructors have a full face helmet that is divided into sections with the probability of impact for each section. The main area of impact is around the face area because we generally look where we are going to land with the least impact areas being at the back/top of the helmet.

I use the BMW helmet system 6. Want to upgrade to the system 7 or similar helmet because of the weight difference with the carbon fibre shell. If you do a considerable amount of riding, touring and such, the lighter the helmet, the easier it is on you.

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Re: Helmets 101

Post by WingAdmin » Thu Mar 01, 2018 2:00 pm

Icon actually makes a helmet with those graphics on it:








As for wanting a full-face with a solid chinbar instead of an open-face helmet, all I can say is this:




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Re: Helmets 101

Post by Sidcar » Fri Mar 02, 2018 4:42 pm

I bought an Arai Chaser-X last December. Arai have changed the shape of the shell so I now take a medium instead of large, though I had to take the thinnest cheek pad out either side. It's a better fit than my old Aria but has two problems.
The shell is higher at the back so there is cold spot on the back of my neck no matter how I position the neck tubes I use.
I find the visor catch a real pain. It's a two position catch. You operate a little lever to release the first catch then hook your finger behind the visor to pulling it off the second catch and upward. Easy in the YouTube video but try it with a winter glove on and it's a real struggle.
Would have thought Arai could do better.

Sid

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Re: Helmets 101

Post by WingAdmin » Sun Mar 04, 2018 9:49 pm

Sidcar wrote:
Fri Mar 02, 2018 4:42 pm
I bought an Arai Chaser-X last December. Arai have changed the shape of the shell so I now take a medium instead of large, though I had to take the thinnest cheek pad out either side. It's a better fit than my old Aria but has two problems.
The shell is higher at the back so there is cold spot on the back of my neck no matter how I position the neck tubes I use.
I find the visor catch a real pain. It's a two position catch. You operate a little lever to release the first catch then hook your finger behind the visor to pulling it off the second catch and upward. Easy in the YouTube video but try it with a winter glove on and it's a real struggle.
Would have thought Arai could do better.

Sid
I too thought the new Arai visor catch was a real pain as well when I first got my new helmet last spring - but after a year of riding with it, I now operate it without thinking just like I did the old one.

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Re: Helmets 101

Post by Sidcar » Mon Mar 05, 2018 3:29 am

In that case I'll give it a bit longer. I find it so annoying, and sometimes dangerous when I'm trying to open the visor in a rush, I was thinking of trimming off the little peg. A bit drastic but at least I'd get the visor open quickly.

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Re: Helmets 101

Post by SilverDave » Fri Mar 23, 2018 11:16 am

Great article .
I would add just one thing ...

WA said :
<< I'd recommend going to a motorcycle store (or better yet - a show) and try on several helmets until you come across one that fits well and feels good. If the store will allow it, try wearing it around for half an hour, to make sure that it doesn't cause any hot spots. >>

I have done this several times, but all I get out of that exercise is how " heavy " the helmet seems.

All the big motorcycle stores around here have at least one person in the accessory dept. who is a " Helmet expert "
He ( or she ) would try various sizes on and rattle the helmet and my head around until they see one that actually fits properly .. not too loose, not too tight .

All the helmets I've kept for 4-5 years were properly fitted by a store " helmet expert", not by my just wearing it around for a half hour.

SilverDave

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Re: Helmets 101

Post by WingAdmin » Sat Mar 24, 2018 12:54 pm

SilverDave wrote:
Fri Mar 23, 2018 11:16 am
Great article .
I would add just one thing ...

WA said :
<< I'd recommend going to a motorcycle store (or better yet - a show) and try on several helmets until you come across one that fits well and feels good. If the store will allow it, try wearing it around for half an hour, to make sure that it doesn't cause any hot spots. >>

I have done this several times, but all I get out of that exercise is how " heavy " the helmet seems.

All the big motorcycle stores around here have at least one person in the accessory dept. who is a " Helmet expert "
He ( or she ) would try various sizes on and rattle the helmet and my head around until they see one that actually fits properly .. not too loose, not too tight .

All the helmets I've kept for 4-5 years were properly fitted by a store " helmet expert", not by my just wearing it around for a half hour.

SilverDave
The first time I tried an Arai, was at a motorcycle show. The Arai expert (who had been doing this for 20+ years) asked my size. I told him Large. He said, "no you're not, you're a medium." I told him that I've been wearing large helmets my whole life (which I had to do, because my head is so long front to back). He said, "let's measure your head, I'd say you're about 56 cm." He got out his tape measure, and wouldn't you know it, it was exactly 56 cm. He told me I needed a Long Oval helmet, and said, "here, try this one." I tried it on, and it was SO tight, compared to what I had been used to. He told me, "that's how it's supposed to fit."

I've been wearing that size of Arai helmet ever since. Most comfortable helmet I've ever worn. I'll never go back!

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Re: Helmets 101

Post by C-dub » Sat Mar 24, 2018 7:28 pm

Since getting our Wing we had to get new helmets. I used to have an HJC, which model I cannot remember. I wanted to go modular this time and ended up with one of the HJC modular helmets. Several months in, now I'm starting to feel excess pressure on my forehead. I mentioned this as I was looking around at the different helmets. That was when the "helmet guy" told me about different shapes and stuff. I really like the modular style and tried the Shoei Neotec. It did seem snug, but was still more comfortable than the HJC I've been wearing since July.

After a little internet research I think the Neotec and newer Neotec II helmets are slightly elongated, while the HJC helmet I have is more round. This explained to me why my wife is comfortable with hers and I'm finding that I am not. Her head is more round than mine.

I'm still having a bit of sticker shock at the thought of spending $700 for a helmet, but I'm getting past it slowly.


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