You’ll forgive us if we’re feeling a bit jumpy. We’re on a visit to Easton-Bell’s offices in Scotts Valley, California, having been extended a mysterious invitation to a facility known simply as “The Dome.” No sooner do we pass through the company’s business offices and enter a pair of security doors (no cameras allowed) than we notice what appear to be a number of elaborate torture devices positioned prominently about the premises. As the hairs on our necks slowly start standing up, a young man walks in, introduces himself as Alex Szela, and begins discussing subjects like “very lethal hits” and “drop-testing body-farm cadavers.” We swallow hard, nod conciliatorily, and cast furtive glances about, half-expecting to see severed limbs poking out from underneath desks.
Perhaps sensing our apprehension, Szela claims that he’s a test-lab engineer and it’s his job to abuse Bell-Easton’s products (which include Bell, Giro, and Riddell helmets, plus components for Easton, Easton Cycling, and Blackburn). Supporting his assertion are several piles of helmets and handlebars in various states of destruction, but our suspicions aren’t completely appeased.
Szela leads us over to a linear impactor, which he describes as the “meat and potatoes” of his testing, and as a brand-new Bell Moto-9 Carbon is unboxed and mounted upside-down in the rig, dangling above a steel, spherical anvil, it becomes clear where things are—ahem—headed. A 4.7-kilogram (10.4-pound) headform, mimicking the approximate size and weight of a size Medium human head and neck, is fitted inside the matte-black helmet. “We really follow through the whole process, similar to what DOT, Snell or ECE would do when they certify a helmet,” Szela says, a little defensively.
Though the testing methods of the standards Szela mentions are similar to one another in concept, they vary in the details. ECE allows a peak acceleration force of 275 gs at the headform, while Snell permits 300 gs and DOT allows 400 gs, but there are differences in the types of drops required, the impact locations, etc. There is disagreement as to which standard is best, and recent years have seen a focus on low-energy testing. Rather than pick a side though, Szela sees this as a pretext to “constantly refine protocol” by regularly doing tests not spelled out by any of the standards, “probing” helmets in different areas in efforts to cause failure. “The standard only does so many impacts per helmet, but we like to explore as many [impact] locations as possible,” he explains. “You want to make sure that whatever’s on your head protects you all over.”
Szela says Easton-Bell performs several thousand tests per year, and we’ll soon have good reason to believe him. He raises the helmet a few feet, punches some buttons on his keyboard, and pulls the pin. Although this is the gentlest test we’ll see today, we find ourselves cringing, imagining our head inside the helmet as it hurtles down the machine’s rail, smacking the anvil at 3 meters/second (about 7 mph). The helmet bounces off the anvil, and Szela—nonplussed—deftly catches it before it lands again, then makes a few mouse-clicks and reports the reading: 55 gs.
Although seven mph sounds like a snail’s pace to motorcycle riders, it’s important to remember that this is the speed at which the helmet is actually striking; even when traveling velocity is much higher, a crasher typically scrubs off energy and speed with his or her body before the head makes contact with the ground. As well, in the real world, most blows are glancing, not the head-on variety suggested by dropping a helmet onto an anvil. Still, the drop method is controllable and repeatable, and variables can be introduced by replacing the spherical anvil with versions that are flat, ridged or pointed—perfect for an engineer with a penchant for mayhem.
For now, though, Szela explains that the way he’ll introduce variability is by altering the drop height in order to change the speed. After repositioning the same Moto-9 in the rig, he raises it a bit higher than he had previously, while his lips betray just the faintest hint of an eager smile. When the pin is pulled this time, a 5 m/sec. (11 mph) velocity is achieved prior to impact, resulting in a measurement of 150 gs. To his credit, Szela nearly manages to disguise the disappointment in his eyes.
Like any reputable helmet manufacturer, Bell says its products shouldn’t be used after one hit. The high-grade EPS from which the liner is made has an impressive ability to absorb impact in a wide range of temperatures, but its one shortcoming is that it’s a one-hit material. Better the helmet than your head, as the saying goes, though we’re beginning to wonder if that would be a unanimous sentiment among those in this room.
Anyway, the one-impact policy apparently doesn’t extend to Szela, and as he lifts the abused Moto-9 higher yet, he avers that this is relevant to the real world since it’s possible for a tumbling rider to strike his or her head more than once during a single crash. We decide to give him the benefit of the doubt, but we’re pretty sure he’d be wringing his hands with glee if they weren’t occupied on the test rig’s keyboard. Alas, despite a drop speed of 6 m/sec. (14 mph), the impact is just 170 gs, demonstrating that increasing velocity doesn’t produce a linear rise in impact force. Sorry, Mr. Szela.
Helmets are designed to sustain damage in crashes, but that only applies to the components that actually contribute to energy absorption, namely, the shell and liner; if a vent cover or piece of trim pops off, it could cause injury. Clinging to that fact as justification, Szela says he records his drops with high-speed cameras and carefully studies the video later to see how the entire helmet reacts to the abuse. Hey, we’ve all got our turn-ons.
Still not appeased, the engineer prepares the rig yet again, this time for a drop of 7.75 m/sec (19 mph), the Snell standard. To achieve this, the helmet must be raised to a height of 11 feet, and the fact that his lab is only nine feet high hasn’t dissuaded Szela, who has overcome this particular obstacle to “science” by removing a ceiling panel. Eventually, the Moto-9 is dropped from its lofty perch, and while the resultant thwack turns our stomach, Szela exhibits only keen anticipation as he peers expectantly at his monitor—only to be thwarted again. Noting a measured impact of just 240 gs, he mutters some preposterous nonsense about Snell requiring a second drop on the same impact point, and performs yet another test, this one at 6.6 m/sec. It peaks at a paltry 200 gs on the accelerometer, so admitting defeat, Szela finally removes the abused helmet and reluctantly hands it over for our inspection.
To be sure, the Moto-9 has seen better days, as its shell is scuffed and scratched, while impressions and even cracks are visible in the liner, but the engineer hardly seems fulfilled by the level of mutilation. He explains hopefully that Easton-Bell is constantly seeking new ways of maltreating, er, testing, helmets, and they’re obsessive in their compilation of data, even availing themselves to whiplash research from Riddell, for example, the largest producer of football helmets.
Because of the drop test’s shortcomings, there’s been growing interest in rotational testing, which is more nuanced and takes into account the dynamic nature of vehicle crashes. There’s still no industry standard for the rotational test, but Easton-Bell is doing its own research with a pendulum-style rotational tester. (If that title sounds innocuous, consider that “the pendulum” in this case is literally a horizontally positioned human dummy that hangs from a chain and is swung so that his head bashes into an anvil.) Surrounded by a chain-link fence, this rig rests idle just a few feet from the linear tester, and Szela eyes it expectantly. Unfortunately for him, our tour guides anxiously maintain that it’s time for us to leave the Dome in order to see Bell’s design center and learn about the amazing custom-fit program (and, presumably, to meet employees who aren’t grinding their teeth in frustration, and who don’t have throbbing veins on their temples).
We don’t argue, and after we sputter out an uneasy farewell to Mr. Szela, we’re briskly herded back toward the peaceful world of office cubicles and coffee machines. Just as the security doors hiss shut behind us, we could swear we hear a strangled bellow from deep within the Dome. “Hey, can anyone hook a brother up with a spare body-farm cadaver?”