{"678789":{"#nid":"678789","#data":{"type":"news","title":" From Using Plant Rinds to High-Tech Materials, Bike Helmets Have Improved Significantly Over the Past 2 Centuries","body":[{"value":"\u003Cdiv\u003E\u003Cp\u003EImagine \u2013 it\u2019s the mid-1800s, and you\u2019re riding your high-wheeled, penny-farthing bicycle down a dusty road. Sure, it may have some bumps, but if you lose your balance, you\u2019re landing on a relatively soft dirt road. But as the years go by, these roads are replaced with pavement, cobblestones, bricks or wooden slats. All these materials are much harder and still quite bumpy.\u003C\/p\u003E\u003Cp\u003EAs paved roads grew more common across the U.S. and Europe, bicyclists \u003Ca href=\u0022https:\/\/allthatsinteresting.com\/bicycle-history\/2\u0022\u003Estarted to suffer\u003C\/a\u003E gruesome skull fractures and other serious head injuries during falls.\u003C\/p\u003E\u003Cp\u003EAs head injuries became more common, people started seeking out head protection. But the first bike helmets were very different than helmets of today.\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/scholar.google.com\/citations?user=Hf8dRC4AAAAJ\u0026amp;hl=en\u0022\u003EI\u2019m a materials engineer\u003C\/a\u003E who teaches a course at Georgia Tech about materials science and engineering in sports. The class covers many topics, but particularly helmets, as they\u2019re used in many different sports, including cycling, and the materials they\u2019re made of play an important role in how they work. Over the decades, people have used a wide variety of materials to protect their heads while biking, and companies continue to develop new and innovative materials.\u003C\/p\u003E\u003Cp\u003EIn the beginning, there was the pith helmet.\u003C\/p\u003E\u003Ch2\u003EPith Helmets\u003C\/h2\u003E\u003Cp\u003EThe first head protection concept introduced to the biking world was a \u003Ca href=\u0022https:\/\/www.helmets.org\/history.htm\u0022\u003Ehat made from pith\u003C\/a\u003E, which is the spongy rind found in the stem of sola plants, \u003Cem\u003Eaeschynomene aspera\u003C\/em\u003E. Pith helmet craftsmen would press the pith into sheets and laminate it across dome-shaped molds to form a helmet shape. Then, they\u2019d cover the hats in canvas as a form of weatherproofing.\u003C\/p\u003E\u003Cp\u003EPith helmets were far from what we would consider a helmet today, but they persisted until the early 20th century, when bicycle-racing clubs emerged. Since pith helmets offered little to no ventilation, the racers began to use \u003Ca href=\u0022https:\/\/www.gearist.com\/the-evolution-of-bicycle-helmets\/\u0022\u003Ehalo-shaped leather helmets\u003C\/a\u003E. These had better airflow and were more comfortable, although they weren\u2019t much better at protecting the head.\u003C\/p\u003E\u003Ch2\u003ELeather Halo Helmets\u003C\/h2\u003E\u003Cp\u003EThe initial concept for the halo helmet used a simple leather strip wrapped around the forehead. But these halo helmets quickly evolved, as riders arranged additional strips longitudinally from front to back. They wrapped the leather bands in wool.\u003C\/p\u003E\u003Cp\u003EFor better head protection, the helmet makers then \u003Ca href=\u0022https:\/\/www.helmets.org\/history.htm\u0022\u003Estarted adding more layers of leather strips\u003C\/a\u003E to increase the helmet\u2019s thickness. Eventually, they added different materials such as cotton, foam and other textiles into these leather layers for better protection.\u003C\/p\u003E\u003Cp\u003EWhile these had better airflow than the pith hats, the leather \u201chairnet\u201d helmets continued to offer very little protection during a fall on a paved surface. And, like pith, the leather helmets degraded when exposed to sweat and rain.\u003C\/p\u003E\u003Cp\u003EDespite these drawbacks, leather strip helmets dominated the market \u003Ca href=\u0022https:\/\/www.helmets.org\/history.htm\u0022\u003Efor several decades\u003C\/a\u003E as cycling continued to evolve throughout the 20th century.\u003C\/p\u003E\u003Cp\u003EThen, in the 1970s, a nonprofit dedicated to testing motorcycle helmets called \u003Ca href=\u0022https:\/\/www.smf.org\/\u0022\u003Ethe Snell Foundation\u003C\/a\u003E released new standards for bike helmets. They set their standards so high that only lightweight motorcycle helmets could pass, which most bicyclists refused to wear.\u003C\/p\u003E\u003Ch2\u003ENew Materials and New Helmets\u003C\/h2\u003E\u003Cp\u003EThe motorcycle equipment manufacturing company Bell Motorsports responded to the new standards by \u003Ca href=\u0022https:\/\/www.helmets.org\/history.htm\u0022\u003Ereleasing the Bell Biker in 1975\u003C\/a\u003E. This helmet used expanded polystyrene, or EPS. EPS is the same foam used to manufacture styrofoam coolers. It\u2019s lightweight and absorbs energy well.\u003C\/p\u003E\u003Cp\u003EConstructing the Bell Biker involved \u003Ca href=\u0022https:\/\/www.gearist.com\/the-evolution-of-bicycle-helmets\/\u0022\u003Espraying EPS into a dome shaped mold\u003C\/a\u003E. The manufacturers used small pellets of a very hard plastic \u2013 polycarbonate, or PC \u2013 to mold an outer shell and then adhere it to the outside of the EPS.\u003C\/p\u003E\u003Cp\u003EUnlike the pith and leather helmets, this design was lightweight, load bearing, impact absorbing and well ventilated. The PC shell provided a smooth surface so that during a fall, the helmet would skid along the pavement instead of getting jerked around and caught, which could cause abrupt head rotation and lead to concussions and other head and neck injuries.\u003C\/p\u003E\u003Cp\u003EOver the next two decades, as cycling became more popular, helmet manufacturers tried to strike the perfect balance between lightweight and ventilated helmets, while simultaneously providing impact protection.\u003C\/p\u003E\u003Cp\u003EIn order to decrease weight, a company called Giro Sport Design \u003Ca href=\u0022https:\/\/www.gearist.com\/the-evolution-of-bicycle-helmets\/\u0022\u003Ecreated an all-EPS helmet\u003C\/a\u003E covered by a thin lycra fabric cover instead of a hard PC shell. This design eliminated the weight of the PC shell and improved ventilation.\u003C\/p\u003E\u003Cp\u003EIn 1989, a company called Pro Tec introduced a helmet with a nylon mesh infused in the EPS foam core. The nylon mesh dramatically increased the helmet\u2019s structural support without the added weight of the PC shell.\u003C\/p\u003E\u003Cp\u003EMeanwhile, as cycling became more competitive, many riders and manufacturers started \u003Ca href=\u0022https:\/\/www.gearist.com\/the-evolution-of-bicycle-helmets\/\u0022\u003Edesigning more aerodynamic helmets\u003C\/a\u003E using the existing materials. A revolutionary teardrop style helmet debuted in the 1984 Olympics.\u003C\/p\u003E\u003Cp\u003ENow, even casual biking enthusiasts will don teardrop helmets.\u003C\/p\u003E\u003Ch2\u003EHelmets on the Market Today\u003C\/h2\u003E\u003Cp\u003EHelmet makers continue to innovate. Today, many commercial brands use a hard polyethylene terephthalate, or PET, shell around the EPS foam in place of a PC shell to increase the helmet\u2019s protection and lifespan, while decreasing cost.\u003C\/p\u003E\u003Cp\u003EMeanwhile, some brands still use PC shells. Instead of gluing them to the EPS foam, the \u003Ca href=\u0022https:\/\/www.helmets.org\/history.htm\u0022\u003Eshell serves as the mold itself\u003C\/a\u003E, with the EPS expanding to fit inside it. Manufacturing helmets this way eliminates several process steps, as well as any gaps between the foam and shell. This process makes the helmet both stronger and cheaper to manufacture.\u003C\/p\u003E\u003Cp\u003EAs helmets evolve to provide more protection with still lighter weight, materials called copolymers, such as acrylonitrile-butadiene-styrene, are replacing PC and PET shell materials.\u003C\/p\u003E\u003Cp\u003EMaterials that are easier and cheaper to manufacture, such as expanded polyurethane and expanded polypropylene, are also \u003Ca href=\u0022https:\/\/schifferbooks.com\/products\/modern-sports-helmets\u0022\u003Estarting to replace\u003C\/a\u003E the ubiquitous EPS core.\u003C\/p\u003E\u003Cp\u003EJust as the leather and pith helmets would look strange to a cyclist today, a century from now, bike helmets could be made with entirely new and innovative materials.\u003C!-- Below is The Conversation\u0027s page counter tag. Please DO NOT REMOVE. --\u003E\u003Cimg src=\u0022https:\/\/counter.theconversation.com\/content\/233315\/count.gif?distributor=republish-lightbox-basic\u0022 alt=\u0022The Conversation\u0022 width=\u00221\u0022 height=\u00221\u0022\u003E\u003C!-- End of code. If you don\u0027t see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https:\/\/theconversation.com\/republishing-guidelines --\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis article is republished from \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\u0022\u003E\u003Cem\u003EThe Conversation\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E under a Creative Commons license. Read the \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/from-using-plant-rinds-to-high-tech-materials-bike-helmets-have-improved-significantly-over-the-past-2-centuries-233315\u0022\u003E\u003Cem\u003Eoriginal article\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E.\u003C\/em\u003E\u003C\/p\u003E\u003C\/div\u003E","summary":"","format":"full_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EAs head injuries became more common, people started seeking out head protection. But the first bike helmets were very different than helmets of today.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"As head injuries became more common, people started seeking out head protection. But the first bike helmets were very different than helmets of today."}],"uid":"27469","created_gmt":"2024-12-09 16:37:12","changed_gmt":"2026-03-19 13:15:25","author":"Kristen Bailey","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2024-11-18T00:00:00-05:00","iso_date":"2024-11-18T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"675792":{"id":"675792","type":"image","title":"Modern bike helmets are made through complex materials engineering.","body":"\u003Cdiv\u003E\u003Cp\u003EModern bike helmets are made through complex materials engineering. \u003Ca href=\u0022https:\/\/www.gettyimages.com\/detail\/photo\/people-in-bicycle-helmets-in-forest-royalty-free-image\/1436148369?phrase=biking\u0026amp;searchscope=image%2Cfilm\u0026amp;adppopup=true\u0022\u003EJohner Images via Getty Images\u003C\/a\u003E\u003C\/p\u003E\u003C\/div\u003E","created":"1733764031","gmt_created":"2024-12-09 17:07:11","changed":"1733764031","gmt_changed":"2024-12-09 17:07:11","alt":"Modern bike helmets are made through complex materials engineering.","file":{"fid":"259458","name":"file-20241114-15-8pfjcp.png","image_path":"\/sites\/default\/files\/2024\/12\/09\/file-20241114-15-8pfjcp.png","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/12\/09\/file-20241114-15-8pfjcp.png","mime":"image\/png","size":1153564,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/12\/09\/file-20241114-15-8pfjcp.png?itok=gUca_fA3"}}},"media_ids":["675792"],"related_links":[{"url":"https:\/\/theconversation.com\/from-using-plant-rinds-to-high-tech-materials-bike-helmets-have-improved-significantly-over-the-past-2-centuries-233315","title":"Read This Story on The Conversation"}],"groups":[{"id":"658168","name":"Experts"},{"id":"1214","name":"News Room"},{"id":"1188","name":"Research Horizons"}],"categories":[],"keywords":[{"id":"187915","name":"go-researchnews"}],"core_research_areas":[],"news_room_topics":[{"id":"71881","name":"Science and Technology"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Ch5\u003EAuthor:\u003C\/h5\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/profiles\/jud-ready-1544003\u0022 rel=\u0022author\u0022\u003EJud Ready\u003C\/a\u003E\u003Cbr\u003EPrincipal Research Engineer in Materials Science and Engineering, Georgia Institute of Technology\u003C\/p\u003E\u003Ch5\u003EMedia Contact:\u003C\/h5\u003E\u003Cp\u003EShelley Wunder-Smith\u003Cbr\u003E\u003Ca href=\u0022mailto:shelley.wunder-smith@research.gatech.edu\u0022\u003Eshelley.wunder-smith@research.gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}