Bike tires made from NASA's bizarre shape-shifting metal are now available to buy

A green prototype of the METL tire with the tread applied. You can see the coil of nitinol through the transparent tire. | Image: The Smart Tire Company The Metl bicycle tire is the first consumer product we're aware of to use nitinol, a NASA-developed shape-memory alloy made of nickel and titanium that can be trained with heat to remember its shape. Compared with traditional bicycle tires, Metl tires will never go flat and will last a lifetime -- at least that's the promise made by The Smart Ti...