Hyundai has previewed a new tire design that has snow chains built right in, which would improve traction in snowy conditions without the inconvenience of manually installing tire chains in the winter. The snow chains would deploy at the press of a button, like something out of Speed Racer, by making use of what Hyundai calls “shape memory alloy.”
The integrated snow chain technology works by running an electric current through six (or possibly more) alloy spokes built into the tire’s rubber. These have a shape memory they revert to when electric current is applied, and they pop out of grooves in the rubber when activated. They then retract when the electric current is cut off, as this video from Hyundai Motor Group explains:
The concept consists of a whole tire and wheel assembly, a departure from current designs. It adds complexity and a few points of failure to a relatively simple design that mostly works, except in certain weather situations, which this is meant to address. Hyundai goes into detail explaining the concept:
The snow chain-integrated tire technology consists of a wheel and tire assembly that feature radial grooves at regular intervals, like a pizza, with modules made of shape memory alloy inserted into these channels.
This technology takes advantage of the shape memory alloy’s ability to return to its original shape when an electric current is applied. During normal driving, the shape memory alloy located inside the wheel is compressed into the shape of the letter ‘L’ and does not contact the road surface. When the driver activates the function, an electric current is applied, causing the shape memory alloy to revert to its original profile; the material forms a ‘J’ shape, pushing the module out of the tire to make contact with the surface, improving grip, stability and safety on snowy roads.
Hyundai goes on to say its tires with built-in chains would feature an added bonus of visually warning drivers when to replace worn-out tires, since the alloy spokes would start to protrude when the tire was at the end of its usable life:
If the surface of the tire is worn down to the height of the module in normal driving mode due to severe tire wear, drivers can easily recognize this degradation so as not miss the tire replacement cycle.
Hyundai Motor Group has patented the design in South Korea as well as the U.S. The carmaker says it’s considering production of the built-in snow chain tire, but the design is pending further development and durability tests in order to be cleared for mass production. It would also have to be cleared by regulatory agencies and deemed safe before reaching mass market Hyundai and Kia cars.