The History of Bicycle Helmets
By Randy Swart, Director
Bicycle Helmet Safety Institute
Summary: This is a page of oral history on helmets, just one man's recollection of how bicycle helmets developed.
In the beginning, there were injuries. From cycling's earliest days there were head injuries. As more roads were paved it is likely that the head injuries increased, since macadam and asphalt are completely unforgiving as crash surfaces. In the 1880's high-wheel users in clubs saw that head injuries were a problem and began using pith helmets. Pith is a crushable material, and was likely the best material available at the time. Although it would probably break up on impact, there were few cars on the roads, so riders needed protection only against a single impact.
Around the turn of the century racing cyclists began using "helmets" made of strips of leather-covered padding, initially with a ring of leather around the head and a wool ring above that. Then the style evolved and the ring of leather around the head was supplemented by strips of leather arranged longitudinally on the head. When I started racing in the 70's we called them "hairnets" and the nicest ones were made in Italy of beautiful soft leather.
By then the interior of the strip was a foam, but it wasn't very protective. They also rotted from sweat. I asked the more experienced racers if the hairnet we were required to use in races was protective, and they said "they don't help at all in the initial impact, but they keep your ears from being ground off while you're sliding over the pavement." Years later lab testing showed that their assessment from field experience was exactly correct.
By the early 1970's club and racing cyclists with shared experience could see that the injuries that were the worst and the major cause of death were head injuries. We could also see that a helmet could do a lot of good. Some riders just ignored that, as they do today. Others began using hockey helmets. Still others turned to the plethora of headgear on the market, including "bump caps" and others that were more illusion than protection.
The Snell Foundation had promulgated the first bicycle helmet standard in the U.S. in 1970, but at the time only a light motorcycle helmet could pass it, and that meant two pounds of unvented helmet.
Very few, if any, helmets were certified to it, and none made their way to bike shops. Since there was no commonly used standard, there was no way for the consumer to find out which helmets were most protective.
In 1974 the Washington Area Bicyclist Association despaired of finding information on the relative protection of helmet brands and formed a Helmet Committee to collect data from ride testing. WABA procured helmets from many sources and began a series of ride tests. At that time we found that the helmets on the market mostly had some kind of shell with a squishy foam liner. None had crushable EPS (picnic cooler) foam until the Bell Biker (below) and the Mountain Safety Research bike helmet came to market in the mid-1970's.
Bike club experience quickly showed that both were far better in performance than the others on the market
The MSR bike helmet was an adaptation of their mountain climbing helmet. It had EPS foam in a ring around the headband, with the top protected to a lesser extent with a suspension system whose nylon straps attached to the shell with deformable hooks. Curves in the hooks were designed to straighten out on impact as an energy management technique. In a few months MSR apparently realized that the suspension system was less effective than the foam section, and that riders impact all over the helmet. They provided EPS glue-on pads to go in the upper area, with a wedge-shaped EPS section between each of the nylon straps of the suspension system. The shell of the MSR was a stiff polycarbonate, probably GE's Lexan.
The Bell Biker also had a hard Lexan shell, and it had a full EPS liner. When it was introduced other manufacturers eventually followed Bell's lead and this type of helmet dominated for a decade. There were still some helmets produced with hard shells and squishy foam liners by Pro-Tec and others, and a notable design called the Skid Lid with strips of hard shell backed by squishy foam.
In the early 1980's Dr. George Snively of the Snell Foundation agreed to work with WABA's helmet committee to provide us with helmet testing. We procured the helmets, did a ride test, and shipped them to Snell, where Dr. Snively tested them for strap strength and impact protection in Snell's lab. Snell maintained a strict division between their certification testing and the testing they did for us. By that time there were 20 or so helmets to be tested, and the testing showed that the Bell Biker, and updated MSR and a helmet known as the Bailen Bike Bucket (below) were the best of the lot.
The Bailen was the first "one size fits all" bike helmet, with an adjustable ring inside that fit sizes 6 7/8 to 8. It had no vents, and both internal and external hard shells.
Dr. Snively gave generously of his time and unparalled expertise to educate the WABA testers in helmetry and helmet standards. WABA's Tom Balderston wrote up the findings and Bicycling Magazine published them--in the face of lawsuit threats from manufacturers--in 1983. That article was a landmark, and alerted consumers to the vast differences in performance between helmets on the market. It helped pave the way for standards to develop.
In 1984 the ANSI headgear committee adopted ANSI Z80.4, the first workable bike helmet standard for the US. The Snell Foundation revised their own standard the next year to adjust the requirements to more realistic levels for bicycle riding impacts. In just a year or so the junk that could not meet the ANSI standard was swept from the market, in some cases by lawsuits. Mid-1980's bike helmets were characterized by EPS foam liners, with ABS or polycarbonate hard shells. Virtually all of them had a simple strap design shaped like a Y on each side. For buckles, most had d-rings or plastic buckles made by Fastex.
In the early 1980's the next big step in bicycle helmet design occurred when Bell introduced their "L'il Bell Shell" infant-toddler design.
To make the helmet lighter, Bell dropped the outer shell, producing a thick all-EPS helmet that was highly protective. The design was actually an adaptation of a helmet Bell had produced for pediatricians to protect child heads after surgery. Bell limited the idea to toddler helmets in the belief that adult helmets would always require a hard shell. In 1986 a designer named Jim Gentes designed an adult bike helmet with some vents and no shell, and formed Giro Sport Design to market the concept. The lighter weight was an instant hit, and Giro began selling large quantities of the helmets to racers and others who could afford the high price.
Giro used an outer cover of thin lycra cloth. The cover was hand sewn in the US and was one of the major costs of producing the helmet.
The all-EPS helmets that followed soon distinguished themselves as protective helmets that had an unfortunate tendency to catastrophic failure in the first blow. To hold the all-EPS designs together better, Pro Tec introduced two or three years later an all-EPS helmet with internal reinforcing. Their Mirage model had a nylon mesh inserted in the foam, clearly visible in the vents.
The mesh is visible in the vents in the second photo above. It worked well, and has been followed by thousands of other designs using internal reinforcing to hold the foam together. The early ones, including the Pro Tec, still had cloth covers and no outer shell.
The next big design step appeared about 1990 with the reintroduction of a shell to cover the EPS, this time in PET (milk jug plastic) and other thin, tough plastics. The shell helped to hold the foam together in an impact and lowered the sliding resistance of the helmet to make it skid more easily on pavement, both important safety features. In just a few years this thin shell design took over the market, replacing both the remaining hard shells and the cloth-covered EPS-only designs. The shell was produced separately from the interior foam, and then glued or taped on.
Another innovation in the early 1990's was molding the foam in the thin shell, by placing the shell in the mold first, then expanding the EPS bead to fill it. The heat of the process then requires a higher grade of shell than PET, usually a polycarbonate, since PET will melt at the temperatures in the mold. The technique fills the shell completely, with no gaps between the foam and shell unless there are quality control problems.
That permitted the designer to produce a more protective helmet with the same thickness.
Designers quickly found that the same technique permitted them to thin the helmet down for more appealing styling and to open up more vents.
In the years since 1990 some manufacturers have continued making the hard shell, mostly in ABS plastic. Most of their models are for skate-style helmets only, where the style endures. In 2001 a company called Hopus Technologies / Aegis Helmets managed to develop a technique to make molded-in-the-shell helmets using an ABS hard shell.
At about the same time as thin shells, manufacturers added a supplemental stabilizer in the rear of many models in the form of a plastic patch or cloth strap in the rear to hook below the bulge in most riders' heads (the occipital bone) and hold the helmet on better. Many innovations in these stabilizer designs have followed.
The most efficient shape for a helmet in a crash resembles a bowling ball. Round, smooth surfaces slide well and "scrub off" energy from a crash, while avoiding any tendency for the helmet to snag and jerk the rider's neck. This has been demonstrated in lab tests. But designers began flogging "aerodynamic" designs in the late 1980's as the aero craze peaked. Greg LeMond wore one in a famous time trial where he came from behind to win the Tour de France. Bicycle helmet shapes have become elongated ever since, basically as a fashion trend, since the aero quality of the helmet has no real effect at the speeds most riders travel.
An unfortunate trend in shapes became evident in the late 1990's as designers began producing helmets with ridges, rear projections and squared-off lines to give them a more stylish appearance. We have ranted against the trend, but without much effect, and have been unable to get provisions in any standard requiring low sliding resistance. We could only hope the fashion will reverse as fashions always do, and lead us back to smoother designs. Finally in 2004 there were signs of at least a few rounder, smoother designs produced for the "commuter helmet" niche in the market. Bell introduced the Metro, followed quickly by a number of others.
The Metro was an intentionally clunky design, but SixSixOne found a design in China shortly thereafter and brought the helmet on the right below, the Allride, to the US market. Weak marketing doomed it to low sales, and the company dropped it from their line after 2005. But the original producer brought it back for 2006 as the Vcan VCK37 (on left below).
In 2006 the round helmet trend advanced in Europe with the introduction of the CASCO Warp II helmet, a very round and smooth design for track racers. The manufacturer advertises it as a more aerodynamic design based on automotive research. Track racers in the UK were early adopters and their demand alone led to backorders for the helmet. It is not clear why the aerodynamic claim led buyers to reject all of the aero research of manufacturers of the elongated designs.
The extreme of the elongated aerodynamic style is the chrono helmet developed in the 1980's for Olympic time trials. This one has a rounded front and usually has a very long tail that rests on the riders back when in the tuck position used by time trialers. Vents are minimal or non-existant. Early models had only a shell without impact protection, but in 2002 Louis Garneau introduced one that met the requirements of the US CPSC standard, and various manufacturers soon began making them to the European CEN standard. We have a page up on current chrono helmets.
Another major helmet shape that crept into bicycle helmets is the "skate-shaped" helmet. Originally developed for skateboarders by Pro-Tec, the style has lower rear coverage, small round vents in the front and even smaller round vents in a circle on top.
The skate style helmet is almost always a hard shell with ABS plastic. Although originally using a squishy rebounding foam that provided the multi-impact performance needed for aggessive skateboarding, the helmets evolved into bicycle helmets because the squishy foam would not perform in harder impacts called out by bicycle helmet standards. After 1999 when the CPSC standard came into effect, big-box retailers were not willing to put a helmet on the floor that could be bought as a bike helmet but did not meet the CPSC standard. As a result, most skateboarders now are buying single-crash bike helmets with crushable EPS foam inside. A few manufacturers are making helmets with EPP foam or other foam that can be certified to both the ASTM skateboard helmet standard and the bicycle helmet standard.
Until the 21st century, bicycle helmet liners were all crushable foams. In the late 80's or early 90's came the introduction of new foam types to replace the simple EPS picnic cooler foam that dates from the 1950's. One of the first was EPP, Expanded Polypropylene, a foam that looks much like EPS but has a slightly rubbery feel. It is extensively used in the automobile industry. EPP has the desirable characteristic of slow return to its original shape after an impact, and is therefore well suited to multi-impact helmets. It is generally considered to have slightly more rebound on initial impact than EPS, and a little less impact attenuation for a given thickness. Although Aria Sonics had an EPP helmet for five years or more, the design was never appreciated by consumers, and its marketing was inadequate to establish its advantages. A Canadian company called Headstart introduced EPP designs in the mid-1990's, but the helmets were not well finished and did not have the quality appearance that was required to sell in the U.S. market by that time.