While bicycling doesn’t produce any pollution, every time you get a flat tire while out on a ride, that rubber tube ends up in a landfill. By one estimate, riders in San Francisco alone throw out more than 100,000 tubes every year, enough to wrap the Golden Gate bridge 33 times. The SMART Tire Company hopes to make flat tires, and all that rubber waste, a thing of the past, with airless bike tires that use technology originally invented by NASA.
NASA developed its airless shape memory alloy tires for use on its lunar and Mars missions; the tires are flexible like rubber, but can work on various terrains, can’t be punctured, and don’t use any air—perfect for allowing a rover to explore another planet without worrying about flats. The tires are made of a material called Nitinol, a combination of nickel and titanium. It’s getting its first consumer application through SMART’s bicycle tire called METL.
SMART has plans to make car tires, too, but it started with biks because the regulatory requirements are lower than the automotive industry, which means they could see a faster time to market, and also because demand is high, says Brian Yennie, co-founder and CTO at SMART, over email. The tires won’t be “ultralight,” so road cyclists might not be interested, but their weight will compare to tires for gravel, mountain, and eBikes, he says. “We argue that there are externalized savings and benefits that increase the benefits beyond just weight,” he adds. “For example, for many cyclists simply ditching spares and repair tools saves more weight than the delta between tire models.”