Think about – it’s the mid-1800s, and also you’re driving your high-wheeled, penny-farthing bicycle down a dusty street. Positive, it might have some bumps, however if you happen to lose your stability, you’re touchdown on a comparatively delicate filth street. However because the years go by, these roads are changed with pavement, cobblestones, bricks or wood slats. All these supplies are a lot tougher and nonetheless fairly bumpy.
As paved roads grew extra widespread throughout the U.S. and Europe, bicyclists began to undergo grotesque cranium fractures and different severe head accidents throughout falls.
As head accidents grew to become extra widespread, folks began in search of out head safety. However the first bike helmets have been very totally different than helmets of right now.
I’m a supplies engineer who teaches a course at Georgia Tech about supplies science and engineering in sports activities. The category covers many subjects, however significantly helmets, as they’re utilized in many various sports activities, together with biking, and the supplies they’re product of play an essential position in how they work. Over the a long time, folks have used all kinds of supplies to guard their heads whereas biking, and corporations proceed to develop new and revolutionary supplies.
To start with, there was the pith helmet.
Pith helmets
The primary head safety idea launched to the biking world was a hat constructed from pith, which is the spongy rind discovered within the stem of sola vegetation, aeschynomene aspera. Pith helmet craftsmen would press the pith into sheets and laminate it throughout dome-shaped molds to type a helmet form. Then, they’d cowl the hats in canvas as a type of weatherproofing.
Hats made out of pith have been utilized by militaries in addition to for head safety whereas biking.
Auckland Museum, CC BY-SA
Pith helmets have been removed from what we might think about a helmet right now, however they continued till the early twentieth century, when bicycle-racing golf equipment emerged. Since pith helmets supplied little to no air flow, the racers started to make use of halo-shaped leather-based helmets. These had higher airflow and have been extra snug, though they weren’t significantly better at defending the top.
Leather-based strip bike helmets have been made within the Thirties.
Museums Victoria, CC BY-SA
Leather-based halo helmets
The preliminary idea for the halo helmet used a easy leather-based strip wrapped across the brow. However these halo helmets shortly developed, as riders organized further strips longitudinally from entrance to again. They wrapped the leather-based bands in wool.
For higher head safety, the helmet makers then began including extra layers of leather-based strips to extend the helmet’s thickness. Ultimately, they added totally different supplies reminiscent of cotton, foam and different textiles into these leather-based layers for higher safety.
Whereas these had higher airflow than the pith hats, the leather-based “hairnet” helmets continued to supply little or no safety throughout a fall on a paved floor. And, like pith, the leather-based helmets degraded when uncovered to sweat and rain.
Regardless of these drawbacks, leather-based strip helmets dominated the marketplace for a number of a long time as biking continued to evolve all through the twentieth century.
Then, within the Seventies, a nonprofit devoted to testing motorbike helmets known as the Snell Basis launched new requirements for bike helmets. They set their requirements so excessive that solely light-weight motorbike helmets may cross, which most bicyclists refused to put on.
New supplies and new helmets
The motorbike gear manufacturing firm Bell Motorsports responded to the brand new requirements by releasing the Bell Biker in 1975. This helmet used expanded polystyrene, or EPS. EPS is similar foam used to fabricate styrofoam coolers. It’s light-weight and absorbs power effectively.
Setting up the Bell Biker concerned spraying EPS right into a dome formed mould. The producers used small pellets of a really onerous plastic – polycarbonate, or PC – to mould an outer shell after which adhere it to the skin of the EPS.
Expanded polystyrene, or EPS, is a foam utilized in styrofoam coolers in addition to the core of motorbike helmets.
Tiia Monto/Wikimedia Commons, CC BY-SA
In contrast to the pith and leather-based helmets, this design was light-weight, load bearing, affect absorbing and effectively ventilated. The PC shell supplied a clean floor so that in a fall, the helmet would skid alongside the pavement as an alternative of getting jerked round and caught, which may trigger abrupt head rotation and result in concussions and different head and neck accidents.
Over the following 20 years, as biking grew to become extra fashionable, helmet producers tried to strike the proper stability between light-weight and ventilated helmets, whereas concurrently offering affect safety.
So as to lower weight, an organization known as Giro Sport Design created an all-EPS helmet lined by a skinny lycra material cowl as an alternative of a tough PC shell. This design eradicated the burden of the PC shell and improved air flow.
In 1989, an organization known as Professional Tec launched a helmet with a nylon mesh infused within the EPS foam core. The nylon mesh dramatically elevated the helmet’s structural assist with out the added weight of the PC shell.
Many racing cyclists discovered teardrop-style helmets to be extra aerodynamic.
Bongarts/Getty Photos, CC BY-NC-ND
In the meantime, as biking grew to become extra aggressive, many riders and producers began designing extra aerodynamic helmets utilizing the present supplies. A revolutionary teardrop type helmet debuted within the 1984 Olympics.
Now, even informal biking fanatics will don teardrop helmets.
Helmets available on the market right now
Helmet makers proceed to innovate. In the present day, many business manufacturers use a tough polyethylene terephthalate, or PET, shell across the EPS foam instead of a PC shell to extend the helmet’s safety and lifespan, whereas lowering value.
In the meantime, some manufacturers nonetheless use PC shells. As a substitute of gluing them to the EPS foam, the shell serves because the mould itself, with the EPS increasing to suit inside it. Manufacturing helmets this manner eliminates a number of course of steps, in addition to any gaps between the froth and shell. This course of makes the helmet each stronger and cheaper to fabricate.
As helmets evolve to offer extra safety with nonetheless lighter weight, supplies known as copolymers, reminiscent of acrylonitrile-butadiene-styrene, are changing PC and PET shell supplies.
Supplies which are simpler and cheaper to fabricate, reminiscent of expanded polyurethane and expanded polypropylene, are additionally beginning to substitute the ever present EPS core.
Simply because the leather-based and pith helmets would look unusual to a bicycle owner right now, a century from now, bike helmets might be made with completely new and revolutionary supplies.