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Smart’s NASA-Inspired Airless Metal Bike Tires Promise Never to Pop

A closeup of METL tires that look like chainlinks

If you’ve ever dealt with a punctured bike tire, it was likely a frustrating experience that ended a good ride. Smart, a new startup company, thinks it has a solution thanks to some NASA-inspired tech. Its new bike tires look like chainmail and don’t require air. But we have lots of questions.

If you’re serious about bike riding, you can easily spend thousands of dollars fine-tuning your ride experience. Given that you’re essentially riding a small frame on two wheels, the tires are easily among the most critical choices you can make. And what you choose depends on the riding you do.

Smart’s new METL tires propose a solution to one of the most common issues you might face on a bike ride—punctured tires. Look closely, and they resemble chainmail links, and that’s no accident. Like the wheels a Mars Rover uses, METL forgoes rubber and air in favor of Shape Memory Alloy Radial Technology. It’s essentially a specialized set of titanium spring tires that don’t require inflation.

A closeup of chainlink tired that are clear and see-through.

NASA originally developed the tech to solve a crucial problem for Mars Rovers. They drive on a planet with no roads and plenty of sharp rocks that could puncture a traditional tire. But on Mars, there are no spare tires. So Rover tires use the same nickel-titanium alloy (also known as NiTinol+) spring setup to get around the problem. When a Mars Rover drives over a sharp rock, the tire bends to match the rock’s shape. Afterward it returns to its original shape.

As Smart puts it, the tires are “elastic-like rubber yet strong like titanium.” But given the metal nature, it’s natural to assume the tires are heavy. Smart doesn’t provide weight metrics currently, and that’s an important detail.

An extreme closeup of a chainlink-like tire.

Bike riders tend to favor light tires, as adding rotational weight adds up more quickly than adding weight to the frame of a bike. According to Smart, “these tires are competitive with many mainstream alternatives when it comes to weight. This includes gravel & mountain bikes, eBikes, automotive tires, and truck tires.”

The other main answer revolves around tire pressure. Frequent bike riders will often fine-tune tire pressure for a smoother ride. According to Smart, the prototypes emulate a standard tire with 100 PSI. For many riders, that’s a higher number than they may prefer.

And of course, we don’t know the price yet. According to Smart, the aim for pricing is “will be more of a premium within their markets, comparable to a high performance or racing tire.” So don’t expect to get these for cheap, at least at first. But if they last longer than the average tire, the math could help pay for itself. We’d have to go wheels-on with the METL to know for sure.

Source: Smart

Josh Hendrickson Josh Hendrickson
Josh Hendrickson is the Editor in Chief of Review Geek and is responsible for the site's content direction. He has worked in IT for nearly a decade, including four years spent repairing and servicing computers for Microsoft. He’s also a smart home enthusiast who built his own smart mirror with just a frame, some electronics, a Raspberry Pi, and open-source code. Read Full Bio »