The Grow-It-Yourself Bike Helmet Grows as You Grow, Is Sustainable

After all, you should also protect yourself, and not just the environment. At least, that’s what one company is proposing with a concept for a product that would revolutionize the industry, should it ever get made. It’s a bicycle helmet made of sustainable materials, which, to boot, grows at the same time as the wearer. That last part comes into play when the wearer is not yet an adult, of course.

The product in question is called the Grow-It-Yourself bike helmet, introduced to the public for the first time in late 2019 and resurfacing again at the beginning of 2021. It represents a collaboration between NOS Design and Polybion, with the former conceiving the project and the latter offering the technology that would, theoretically speaking, make it a reality.

In fewer words, we’re talking about a bike helmet made of hay and fungi.

No doubt, that’s a surprising choice for material, but the idea behind the project is that the plastic foam inside modern bike helmets is, number one, not eco-friendly and, number two, not able to adapt itself to a growing head. NOS Design conceived the project with two particular groups of riders in mind, namely children (who will have to go through several helmets before reaching adulthood) and urban commuters, especially ride-sharing fans (who are almost never offered a helmet with the bike or scooter they take out).

Whether wearing a helmet is of any use in real life is bears no relevance here. Bike helmets are not mandatory for adult cyclists in most territories, but many of them still choose to wear them and, after one or several crashes, some even swear they saved their life.

With that in mind, NOS Design believes ride-sharing users should also get protection, which is when this product would come in handy. Instead of a shell with plastic foam lining, it’s made of hay and mycelium, which is the vegetative part of a fungus. At the time this bike helmet was conceived, mycelium was already being included in construction materials, because of its tightly-woven structure, which makes it strong and durable, and the fact that these filaments are self-adhesive to whatever surface they grow on.

“[The helmet] is 100% compostable, breathable, and impact resistant,” NOS Design says. “The helmet reduces the use of plastics in a product that will be disposed of in a short time due to the child’s growth rate.” For adult wearers, disposing of the helmet would occur at the end of its lifecycle, which is unspecified. Within one month, it would decompose completely.

To further work on the study, NOS Design partnered with Polybion, a company that developed Fungicel, a patented, mycelium-based product they use in textiles. The conclusion was that the helmet could grow “like foam” and offer protection in case of an impact.

In addition to being strong and all-natural, mycelium is fire-resistant and affordable. It’s so affordable that a cyclist could grow it in their backyard, hence the Grow-It-Yourself name.

In short, a bike helmet built using mycelium would be an environmentalist’s dream come true. It’s ok if you sensed a “but” coming, it’s on purpose: NOS Design never elaborated on what kind of protection the helmet would actually be capable of offering or whether they had one such helmet tested accordingly. Neither did they say what would happen to adult wearers whose helmets kept growing in case of a crash. We all know that one of the rules meant to ensure a helmet’s efficiency is a proper fit.

That said, this is just a concept for a possible alternative to plastics in bicycle helmets, one that is showing some signs of being efficient. As such, it is not without merit, and would benefit from further study.