08 May Bob Weber and his helmet company 6D Helmets create what is likely to be a revolution in head protection
Bob Weber and his helmet company 6D Helmets create what is likely to be a revolution in head protection
6D Helmets Designs Revolutionary Head Protection – Cycle World Magazine
In my Wheel Spin column way back in the August 2010 issue, I lamented the lack of technological advancement in helmets—specifically, the protection side of the equation. The overall basic design hadn’t changed much from the first real helmets of the 1950s; yes, there has been progress with aerodynamics, ventilation, shields and their pivot mechanisms, moisture-wicking comfort liners, etc. But the same basic construction of a fiberglass outer shell with a monolithic EPS (expanded polystyrene foam, similar to the once-ubiquitous foam coffee cups) inner liner has remained unchanged for the most part. I couldn’t understand how all other riding gear could be making great technological strides in increasing rider protection, yet helmet protection design was so stagnant. I’ve had a couple of friends suffer traumatic brain injuries in crashes that didn’t cause any major visible damage to the helmet and wondered what more could’ve possibly been done to help them and others.
Longtime motorcycle industry business manager Bob Weber had seen his share of traumatic brain injuries suffered by fellow riders from his professional motocross racing experience and his time at a well-known off-road company. With the ever-increasing skill and daring of today’s riders, he’d seen the short-term and long-term effects of those injuries to riders when things go wrong and decided to do some research to find out the why and how. He soon discovered that the biggest factor in the majority of traumatic brain injuries is what is called “angular acceleration.”
The human brain is suspended and protected inside the skull by a thin membrane called the dura and cerebrospinal fluid that acts as a natural cushion against movement. Numerous medical research scientists discovered that it’s not linear impacts that do the most damage; in the more common angular or “oblique” impact to the skull—if you think about it, most of the hits to helmets are at an angle, hence the long scratches and gouges you usually see on the shell of a crashed street lid—the brain actually rotates as inertia from hitting an immovable object causes it to move inside the skull (note that those same researchers also found that angular acceleration occurs even in straight-on hits as well). This rotational movement shears the fragile brain tissue and tears apart the vital bridge veins that supply blood to the brain…neither of which are good.
Weber saw that nearly all helmets did nothing to mitigate this problem. “The monolithic piece of foam connected to the shell is one unit, and it basically takes your head with it when you hit the ground,” Weber says. “If we could give some relief to that connection, it would hopefully reduce the transfer of that rotational energy in an impact.” Numerous medical research journals have been published stating that angular acceleration is the leading cause of traumatic brain injuries.
The Idea: The EPS inner liner in your helmet may be made from the same type of material as foam coffee cups, but one reason it’s still used is because EPS is great at absorbing energy at a nice and predictable rate. Because it crushes to help bring your head to a controlled stop, EPS doesn’t have any rebound energy that could cause your brain to suffer another bounce movement, which would be very bad at this point. But it can’t deal with angular acceleration by itself.
Weber had some experience with helmet design at his previous employer, and his mind continued to chew on a method to solve the angular acceleration problem. “I was road cycling, just thinking about how to solve the problem, and I thought of separating the EPS into two layers,” Weber says. “Knowing that EPS is kind of fragile, how can we separate the two layers and have it be functional without putting all of the energy in one location? So I came up with the idea of an elastomer damper. But I knew I needed an engineer, somebody who was familiar with elastomers. That’s when I contacted Robert.”
Robert Reisinger is a mechanical engineer and former professional motocross racer as well. His expertise with elastomers comes from his years designing mountain bike suspension (he holds numerous patents) through his former company Mountain Cycle. “I spent a great deal of time, about three years, on the development process of figuring out elastomers,” Reisinger says. “I got into chemically formulating my own elastomeric materials and cutting my own molds and casting my own elastomers, learning about densities and the way they worked, their compressive and response ratios.”
Reisinger designed an hourglass-shaped elastomer damper to isolate the two EPS liners, with 27 of the dampers strategically placed between them. This shape, when combined with the elastic properties, enables the damper to progressively manage energy in all six directions of a three-dimensional space. This omnidirectional suspension (ODS) capability is said to provide “six degrees of freedom” in engineering terms (basically the same elements as the six movement axes measured by the IMU of a Yamaha R1). That term became the inspiration for the company name: 6D.
So in a simplistic sense, the ODS is basically like suspension for your head. There is a small air gap between the inner and outer liner, with the ODS compressing or shearing in any direction when subjected to an impact, which significantly reduces the energy transfer that causes your brain to move in a linear or rotational direction, resulting in less chance of injury to that vital organ in your skull.
So in a simplistic sense, the ODS is basically like suspension for your head.
And, no, ODS is not the first technology to address angular acceleration. There are a couple of other concepts, the most well known being MIPS (Multi-directional Impact Protection System), which uses a low-friction inner EPS liner that can slip inside the outer liner. While having a lot of merits, the MIPS involves a simple slip plane in one dimension, and it has no benefit for reducing any linear transfer of energy like ODS. And unlike ODS, it also has some pretty significant constraints based on the shape of the human head; it can slip in some directions better than others. The farther you get away from a 45-degree impact strike, the more difficulty it has providing its benefits.
Long, Hard Journey to Production: The first prototype ODS liners were made entirely by hand by Weber in his garage. “I would take two helmets of the same model, disassemble the interiors, and then I kind of custom-carved out an inside liner by shaving the outside surface down,” Weber says. “And then the second one, I carved out the inside surface, and then we installed a series of dampers in between. We put them back together, took those to the laboratory, and asked Terry Smith at Dynamic Research (a research/development/consulting laboratory/testing firm) to test them for us.”
Even with the crude prototypes, the test results that came back were impressive enough to warrant bringing their idea to a composites manufacturer that builds helmets for numerous brands. The manufacturer was skeptical about the ODS technology until it tested the prototypes in its own laboratory, and that’s when the first revelations began to come to light.
“When they tested the first prototypes, they came back and said, ‘Wow, it does pass the (helmet standards) tests,’” Reisinger recalls. “They didn’t have the rotational testing equipment to see those huge number differences in the rotational energy management. But they could see different numbers on the machines they had. We serendipitously started looking at the plots closer and realized that at the initiation of impact, our plots looked really different. And so we started testing at lower velocities because that was one of the key elements in the journal reports, that the brain is not being protected well in helmets because they’re designed for such a high velocity impact.”
The helmet industry revolves around various safety standards, the most well known being the DOT (US Department of Transportation) FMVSS 218, the ECE (Economic Commission for Europe) 22.05 standard, and Snell. Part of the tests all involve dropping the helmet to impact it at different spots and speeds with various objects, with varying limits on the amount of energy that can be transferred to the test dummy headform. The issue is that those limits are all on the high end of the scale because standards usually involve…well, limits. And you obviously want protection from that one-in-a-hundred devastating impact. But it’s the 99 percent of all other real-world impacts that aren’t so devastating where traumatic brain injury still occurs that can have major long-term health effects—and conventional helmet technology falls short because the construction is built stiff enough to withstand the maximum test limit.
More lab testing eventually showed that the 6D ATR-1 off-road helmet provided not only a massive reduction in angular acceleration compared to the competition (up to 80 percent) but also a reduction in linear G forces of up to 42 percent at lower test velocities of 6m/second and 3m/second. Those lower numbers put the 6D well below the limit listed in medical studies as the threshold for concussion, while other helmets were easily into the concussion zone. But it’s not just the peak Gs where the 6D excelled; the 6D also significantly increased the TTP (Time To Peak), a measure of the time in milliseconds for the energy of an impact to reach maximum G force. All of this adds up to more of a chance for the rider to avoid a traumatic brain injury, according to Weber and Reisinger.
Interestingly, Tyler Shaw, a San Diego State University graduate student, saw the potential in the ODS and wrote his bioengineering master’s thesis on the ODS concept compared to conventional helmet technology. A master’s thesis requires substantial proof to back up its statements, so 6D and Dynamic Research’s testing methods and data had to be qualified with a thorough analysis. Shaw’s 87-page thesis validated Weber and Reisinger’s work and may be published in the future.
Getting a helmet built in production is no easy task, and it was made much more difficult by figuring out a way to easily assemble the ODS liner. Weber and company spent a lot of money on purchasing competitive helmets for testing, countless overseas flights, tooling (“We threw away a lot of tooling on the motocross helmet,” Weber says. “It was just, ‘Well, that’s not going to work.’ And that was $50,000 gone…”), etc. And then once they finally had the production helmets, how would they be accepted in the notoriously fickle motocross fraternity?
Trial by fire: It didn’t take long for the 6D ATR-1 helmet to cause a buzz in the motocross world. Weber provided his first helmets to the GEICO Honda team for the 2013 Supercross season, and right away they were given a trial by fire on live national TV by team riders Eli Tomac and Zach Bell. Tomac went headfirst into a set of hard-packed whoops at the Oakland Supercross during the main race and reported that his head was clear right after the crash. But Bell’s crash in his heat race at the Dallas Supercross was far more serious; while taking off over a triple jump, he became separated from his bike and slammed into the ground from a height of around 20 feet. Although Bell was motionless at first, he said that was because the wind was knocked out of him and that he was conscious the whole time. He passed a medical concussion test to continue racing that night, winning his next race.
The ODS technology has started to spread into the bicycling world, with Reisinger developing a variation of the system called ODS-II. The manufacturer of those helmets reported back to Weber that, “Your data looks really, really good. You’re 50 to 100 Gs less than our other helmets that we’re manufacturing.” And the technology is already being adapted to other sports, including football. 6D and Dynamic Research collaborated on a project that was awarded a research grant for being one of five finalists out of 125 entrants in the NFL’s “Head Health Challenge III” in 2015, an open competition to find the next generation of head protection for those athletes. Anyone who’s been following sports medicine news lately has come to know the term “CTE”, an abbreviation for chronic traumatic encephalopathy, which is a progressive degenerative disease of the brain caused by repeated brain trauma such as concussions. Reisinger developed a version of the ODS that can withstand multiple impacts yet still provide superior protection, and Weber hopes that the continued research from the grant will pay dividends to the motorcycling sport he really loves.
“I think the coolest thing for us is not really the exposure and the benefits that will come from awareness that we were selected for this but the information that we’ll learn about the multi-impact materials,” Weber says. “How can we optimize or modify them based on what we learned through testing with Terry and Dynamic Research, and ultimately what can that turn into down the road? What can that provide us for the motorcycle community (in the future)?”
The 6D ODS technology is continually evolving, and Weber is not sitting still even though he’s got his feet on the ground despite all the kudos showering on the company for its achievements. Talk to Weber and Reisinger and you immediately know the only reason they’re doing this is to make motorcycling safer. “We’ve certainly had concussions and riders knocked out in our helmet by now,” Weber admits. “That just goes to show that we’ve all got more work to do; we’ve still got to make the products better.”