In the past 50 years, as helmet designs have become more sophisticated, adult cycling deaths in the United States have not declined—they’ve quadrupled. As I dug into the history of these humble foam-and-plastic shells, I learned that helmets have a far more complicated relationship to bike safety than many seem ready to admit.
In 1883 the League of American Wheelmen paraded in Manhattan to celebrate the group’s third anniversary. At the time, the penny-farthing’s supersized front wheel offered more cycling efficiency than its predecessor, the velocipede—and also threatened taller falls for riders. Face-dives were a common hazard. A significant-enough number of American Wheelmen took “headers” during their Fifth Avenue procession for the New York Times to notice: “Twenty bicycles were broken in this process but no one suffered anything worse than a good shaking,” the paper remarked.
As mass production made bicycles cheaper and more commonplace, the need for head protection grew increasingly obvious. Cyclists’ earliest choice was a single-use, plant-based pith helmet (basically, a safari hat) that broke upon impact. Next up, a leather halo padded with wool or cotton—referred to as a “hairnet”—did little more than protect a cyclist’s ears and face “from dragging the ground when sliding across pavement,” as the product review website Gearist put it.
It wasn’t until 1975 that the first modern bike helmet, the “Bell Biker,” emerged, with an expanded polystyrene liner and stiff plastic shell. The modern helmet, unlike its predecessors, was designed to cushion collision impacts, absorbing shock so the human head didn’t. This made it potentially lifesaving in slow-speed crashes—for example, if a biker hit a pothole and flew off the handles. “The primary way they protect your head is by their own self-destruction,” said David Halstead, a biomechanical engineer at the University of Tennessee and founder of the Southern Impact Research Center, a private testing company. “I would never ride without one.”
The “bicycle boom” was underway, with an estimated 60 million bikes in use by 1972—a trend kindled by an increase in environmental consciousness, a national energy crisis, and the growing popularity of physical fitness, scholars wrote in a 2020 paper on the history of helmet mandates. Though helmets had not yet emerged as bike safety’s primary symbol, their design evolved. They became lighter, thanks to polyethylene terephthalate (or PET, as in a soda bottle or clamshell plastic) and other novel, thin-but-strong plastics. New nylon straps and plastic buckles helped keep everything in place.