Airless bike tires made with NASA technology are now on sale

The METL tire is made from a shape memory alloy, making it elastic like rubber yet strong like titanium.
Jijo Malayil
METL bike tire from the SMART Tire Company
METL bike tire from the SMART Tire Company


The much-hyped airless tire technology developed by NASA for its rovers, later commercialized for terrestrial use by The SMART Tire Company (STC), is now available for sale. 

According to a Kickstarter campaign, the SMART METL tires designed for bikes have minimal rolling resistance (less labor for you), require no air pressure, ride smoothly like pneumatic tires, and last the lifetime of your vehicle. They also look exceptionally stylish as well.

The model won two innovation awards at this year's Consumer Electronics Show (CES) in Las Vegas as Honorees in two categories: Vehicle Tech & Advanced Mobility and Sustainability, Eco-Design & Smart Energy.

"We're building a bicycle tire first because it allows us to build core capabilities and put an extremely cool product in people's hands more quickly, Brian Yennie, Co-Founder of STC, said. 

Right now, the firm will sell road/gravel tires in size options of 700 x 32c, 35c, and 38c for this commercial launch of the technology. According to the manufacturer, the 35c model weighs 450 grams (16 oz), which is in the center of the weight range for pneumatic tires of similar size.

Practical and sustianable

The fundamentally unsustainable tire industry's sustainability and increased road safety are the firm's two critical objectives behind introducing puncture-less tires in the market. The company was conceived in 2020 as part of the FedTech NASA Startup Program. 

The NASA Glenn Research Center and SMART collaborated to create the METL tire for the agency's Space Act Agreement startup program. The two companies made tires employing memory metals that might withstand the extreme conditions of space. According to SMART, the outcome is a tire that is impervious to punctures and has a long lifespan.

Based on NASA's shape memory alloy (SMA) technology, each METL tire has a central spring that wraps around the tire like a "slinky". That spring is composed of NiTinol, a nickel-titanium alloy with a form memory characterized as elastic and strong like rubber.

It's significant to note that when NiTinol is put under strain, it initially deforms before returning to its previous shape. Due to this property, the Metl tire can softly compress and rebound, offering a comfortable ride similar to a pneumatic tire.

The tire's removable tread and sidewalls are poly-rubber, which encases the spring. The manufacturer claims this system uses only half as much rubber as a typical tire. Additionally, the primary tire should endure the bike's lifetime, even if the tread may need to be replaced every 5,000 to 8,000 miles (8,047 to 12,875 km).

In an earlier interview with IE, Yennie explained that "without pressurized air inside your tires, punctures are no longer a concern. Even large tears won't slow these tires down: you could stick a kitchen knife right through and keep on riding because it won't affect the structural integrity of the tire."

Replacement tires provide 75 percent of the tire industry's earnings, according to SMART. As a point of comparison, the United States generates over 246 million rubber waste tires per year. STC hopes its innovative tires will upend the $250 billion tire market.

The firm reduced material costs by over 85 percent from the prototype stage, and the tires are expected to cost around $100-150. We will have to wait and see if this technology can revolutionize the automobile market.

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