Behind the Scenes: Designing & Testing Bike Helmets with MET

How a lot do you actually learn about your bicycle helmet? Hopefully, you already know that it matches nicely and appears good, and you might have an consciousness of a few of its fancier options, like its rotational influence safety know-how, its dual- or single-density EPS, its retention system adjustability, and so forth, however what do you actually learn about the way it has been examined, and thus the way it would possibly behave while you take a knock?

All bike helmets have to be licensed on the market in most components of the world, and every area has completely different guidelines for that certification. A helmet goes by way of pretty rigorous testing to exhibit its capacity to dissipate influence vitality away from the wearer’s cranium, a minimum of within the case of linear impacts. Each model is topic to these checks with out exception.

For MET, the usual security take a look at procedures merely aren’t rigorous sufficient. The Italian Helmet producers subsequently take issues into their very own arms, at their very own take a look at laboratory, to make sure their helmets not solely meet the necessities for certification, however go manner above and past them.

To get an insiders have a look at helmet design and testing, we’ve teamed up with MET Helmets to carry the lid (excuse the pun) on the mysteries surrounding all of it. We go into element on the necessary shock absorbing take a look at procedures carried out for CE, CPSC/US, AS/NZ, NTA, and ASTM certification, explaining what every one is for, and we additionally take a better have a look at the extra-curricular stuff MET is doing to make sure their helmets are providing prime notch safety to the crashing rider.

All images are credited to @ulyssedaessle and @met-helmets, until in any other case acknowledged

What security checks do bike helmets bear?

The quick reply is, it relies upon. The place you’re on the planet will decide the protection necessities that your helmet needed to meet earlier than it was licensed on the market in that area.

It’s attention-grabbing that the powers that be, those that govern what the particular helmet security necessities are within the completely different areas, make no distinction between highway, gravel and (open face) mountain biking helmets. Past passing the essential checks set out by the related certifications (EN, CPSC, AS/NZ, NTA, ASTM) the hones is upon the producer to over-engineer their helmets to go above and past within the title of conserving riders as protected as doable within the occasion of a crash.

And most do, after all, typically including varied rotational influence safety applied sciences, dual-density EPS, and including prolonged protection to the rear to confer extra safety to the occipital portion of the top – a characteristic seen extra generally on mountain biking helmets.

Italian-brand, MET Helmets, is a type of producers. The rationale they can go the additional mile with helmet security is as a result of they’ve their very own testing laboratory at their HQ in Talamona, close to Lake Como. Earlier than we get into that, let’s take a better have a look at what the necessary helmet security checks appear like, and what’s required for official certification in numerous components of the world.

Helmet Security Certifications & Take a look at Outcome Minimal Necessities

EN 1078 / Europe (and many of the world)

In any take a look at, absolutely the restrict for vitality transmitted to the top throughout an influence is 250 g. That’s measured utilizing a tri-axis accelerometer, with every helmet receiving two impacts – gnarly crashes can simply contain a couple of blow to the top. The checks make use of two sorts of anvil – the thing the helmet is colliding with when dropped from a mono-rail drop tower. In one of many checks, the helmet is dropped onto a flat anvil from a top of 1.5 meters. In one other, the helmet is dropped onto a Curb-shaped (pointy) anvil from a top of 1.07 meters.

These checks are carried out beneath a wide range of situations; chilly, sizzling and ambient temperatures, after a interval pf being sprayed with water, and after a interval of UV publicity, all to simulate the situations helmets would possibly see out on the highway or the path. Moisture and UV radiation can expedite the degradation of EPS, therefore the inclusion of these situations within the take a look at. The checks carried out for certification in different components of the world are very comparable, however they’ve barely completely different necessities by way of how a lot vitality is permitted to be transmitted to the rider’s head throughout an influence.

Along with Linear Affect Testing, MET additionally perform Rotational Affect Testing of their helmets at their in-house laboratory in Italy. This goes above and past what’s required by the assorted security certifications listed right here. Whereas MET take a look at this facet of their helmets’ safety properties in-house, additionally they submit lots of their helmets to the unbiased helmet testing facility at Virginia Tech.

CPSC/USA

Checks carried out for CPSC / USA certification are as follows:

• Helmet dropped onto a flat anvil from a top of 2 meters (video beneath)
• Helmet dropped onto a curbstone and hemispherical anvil from a top of 1.2 meters
• 4 Impacts per Helmet Examined
• Power restrict transmitted to the top throughout any single influence is 300 g, as measured by a linear accelerometer
• Circumstances examined embody chilly, sizzling, and ambient temperatures, in addition to one whereby the helmet is examined after immersion in water for 4 to 24 hours

AS/NZ

Checks carried out for AS / NZ certification are as follows:

• Helmet dropped onto a flat anvil from a top of 1.5 meters
• Anvil dropped onto the helmet that’s mounted on a power transducer – from a top of 1 meter
• 4 Impacts per Helmet Examined
• Power restrict transmitted to the top throughout any single influence is 250 g for flat impacts, 500 N for the power switch take a look at with a curbstone anvil
• Circumstances examined embody chilly, sizzling, and ambient temperatures, in addition to one whereby the take a look at is carried out publish immersion in water

ASTM Certification for Full Face Helmets (1952-15 for DH MTB and 2032-15 for BMX)

This US Certification is made particularly for assessing Full Face Helmets which can be typically required for Enduro or Downhill Mountain Bike Racing, or BMX Racing. The take a look at assesses the protection of each the primary physique of the helmet and the chain bar, and is a bit more complete as such.

The checks for ASTM Certification are cut up into two classes; one for the primary physique (shell) of the helmet, and one other for the chin bar.

Checks for the shell:

• Helmet dropped onto a flat anvil from a top of two meters
• Helmet dropped onto a curbstone anvil from a top of 1.7 meters in ASTM 1952-15 for DH MTB Helmets; drop top is 1.3 meters in ASTM 2032-15 for BMX Racing)
• Helmet dropped onto a hemispherical anvil from a top of 1.7 meters in ASTM 1952-15 for DH MTB Helmets; drop top is 1.3 meters in ASTM 2032-15 for BMX Racing)
• Power restrict transmitted to the top is 300 g, as measured by a linear accelerometer
• 4 impacts on the shell, per helmet examined

Checks for the chin bar:

• Helmet dropped from a top of 40cm onto a flat anvil
• Restrict of the deformation admitted on the chin bar is 60mm
• 1 influence per helmet on the chin bar

NTA 8776 (not necessary): Certification with the next influence pace

There’s one other CE Certification referred to as the NTA 8776 customary. It’s a comparatively new Dutch customary created for helmets of pace pedelec riders, the place the pace pedelec is able to offering help as much as speeds of 45 kph. In these checks, the influence pace is elevated in keeping with the quicker common speeds related to using these bikes.

• Helmet dropped from a top of 2.15 meters onto a flat anvil
• Helmet dropped from a top of 1.5 meters onto a curbstone anvil
• Power restrict transmitted to the top is 250 g, as measured with a tri-axis accelerometer
• 2 impacts per helmet examined

Helmets submitted for NTA Certification are examined beneath a wide range of situations; excessive temperature (+50° C 4-6 hours), low temperature (-20° C 4-6 hours), and synthetic ageing (UV at 125 W for 48 hours plus water spraying for 4-6 hours). 

So, how do producers ensure that their new helmet designs will move the mandatory checks?

Designing a Secure Bike Helmet

The method of designing a helmet varies between producers. Some begin with 2D drawings, after which create a 3D sculpture of the helmet to approve the design and validate its form. The difficulty with that strategy is that, generally, the construction of the ultimate helmet fails laboratory testing, and the producer should begin the helmet design once more from scratch. Ulysse of MET Helmets tells us they take a unique strategy that does, after all, contain 2D-drawings and 3D-sculptures, but additionally depends closely upon computational modelling previous to the creation of any pricey tooling or precise manufacture.

At their R&D facility in Talamona, the MET Helmet designers are in a position to go straight from the drawings and sculptures of the brand new helmet mannequin, and plug them straight into modelling software program that is ready to simulate impacts with a excessive diploma of accuracy. It may possibly simulate a nigh-on infinite variety of situations various anvil form, influence pace, influence power, temperature, humidity, all whereas tweaking the construction of the helmet to make it as sturdy as doable. 

The computational algorithm utilized by the R&D crew relies on thousands and thousands of information factors collected from 1000’s of actual helmet security checks carried out on the MET Testing Laboratory. Information collected from each take a look at is used to enhance the robustness of the pc modelling, making the method of designing every new mannequin of helmet increasingly streamlined.

By their very own in-house testing, MET found that, whereas a helmet can move the protection necessities set out by the Certifications talked about above, that very same helmet can also allow the anvil to come back into contact with the wearer’s cranium, or get very, very near it. So far as they’re involved, such a helmet shouldn’t be set free the door. That’s why they design their helmets to confer safety that’s manner above and past the necessities of the requirements listed.

Because of the robustness of their computational modeling, in current occasions a minimum of, MET has by no means had a brand new helmet mannequin developed and manufactured that has then gone on to fail any of the usual take a look at necessities. That highlights the effectivity of their strategy, and is much less wasteful than a extra trial and error strategy. 

Whereas many manufacturers select to make use of dual-density EPS foams inside their helmets (Fox and Troy Lee Designs, for instance), MET select to make use of a single-density EPS on all of their helmets whereas optimizing the construction for its influence vitality dissipation traits.

Not all helmets are made equal

The standard of a helmet, by way of its capacity to guard your head throughout an influence, will probably be decided by the protection applied sciences it packs in; its rotational influence safety know-how, its development, the construction and thickness of the EPS and so forth, however it can be affected by the humidity of the setting wherein the in-molding course of occurred. A helmet made in summer season can end up fairly completely different to a helmet made in winter, for instance, and that exhibits within the influence take a look at information.

Because of this MET take high quality management very critically. Batch testing of helmets is just not necessary, a minimum of for helmets offered in Europe. However, as a result of potential for seasonal variation in manufacturing high quality and different components that may affect the ultimate product, MET take it upon themselves to go above and past the necessities of the CE Norm, testing quite a few helmets from each single batch produced.

They’ve three staff in Asia who’re working to QC the manufacturing course of. They ship samples instantly from the manufacturing line to the MET testing lab in Italy to make sure every batch meets the protection necessities.

Designing a helmet to suit everybody

After all, the relevance of rotational influence know-how, EPS densities, and helmet development is completely written-off if the helmet in query is a poor match. Right here, a significant problem is posed. The human head varies not solely in measurement, but additionally in form; even should you and I’ve the identical head circumference, the probabilities of our heads being the identical form are negligible.

Now, sure manufacturers will promote you a helmet that’s custom-made particularly on your personal head dimensions, often at an eye-watering worth. Nonetheless, for many manufacturers aiming for extra reachable worth factors, a extra common strategy is required, particularly in the event that they want to embody costly rotational influence safety applied sciences akin to MIPS and the like.

Having been within the enterprise of designing and producing helmets for over 35 years, MET has a complete financial institution of information and a large breadth of data and expertise of helmet match. Thus, the R&D crew has an excellent thought of easy methods to design a helmet to suit nicely on, and be protected for, a wide range of completely different head shapes. MET tells us their design crew is continually updating that financial institution of information measuring the top form and circumference of MET’s sponsored riders, employees members, and members of the general public to get information from an excellent cross-section of society.

Years in the past, MET used to accommodate for various head shapes by adjusting the inner form based on which market the helmet was to be offered in. They used to, for instance, produce a helmet form that was particular to the Asian market, as they figured that the form of a few of their fashions was too slender for many riders in that a part of the world. These days, they can take a extra common strategy due to advances in retention system design.

Their 360° head belt, a part of the Secure-T retention system, is an innovation of theirs that will get round head-shape variety. I’ve used the system on quite a few MET Helmets, together with the Parachute MCR; in my expertise, the retention system does an excellent job of cinching down equally across the head, with no uncomfortable stress factors to talk of. It additionally permits for simple vertical adjustment of the cradle so most riders can get that in-the-helmet feeling, moderately than feeling as if their helmet is just perched atop their cranium.

MET take an in depth have a look at their goal market when designing the match for any new mannequin. For instance, within the design of the MET Trenta 3K Carbon MIPS highway helmet, weight was very excessive on the checklist of priorities. In spite of everything, it’s the helmet worn by Tadej Pogačar and different members of the UAE Crew Emirates. Conscious of that, MET set about designing an ultra-compact helmet that may enable each member of the crew to put on a small helmet, giving them a small weight benefit over having to put on the medium. It’s the common match supplied by the Secure-T Upsilon Retention System that allowed for that.

After all, such common approaches to helmet match merely gained’t lower the mustard for some folks, and a custom-approach is usually one of the best and most secure manner ahead. With this viewers, I really feel I don’t have to stress the significance of getting an excellent helmet match. You guys don’t have to be taught easy methods to suck eggs.

Who’s MET Helmets?

Based in 1987, MET Helmets was the primary helmet model in Europe. Created by Massimilliano Gaiatto and Luciana Sala, MET remains to be a family-owned firm based mostly in Talamona, near Lake Como and surrounded by the paths of the Italian Alps.

The helmets developed so much since their first creations within the 80s.

For 25 years, MET Helmets have been solely produced in Italy. Although MET are not producing in-house since 2012, they nonetheless have an enormous affect over the processes as they custom-design their very own tooling for the job thanks for the understand how acquired.

MET are one among few European helmets manufacturers to have an full inner laboratory in Europe. In addition they are one of many few helmet specialists, providing solely helmets and protecting clothes for cyclists.

Uncover extra right here:

met-helmets.com

This text was sponsored by MET Helmets