Cars have been rolling on pneumatic tyres for more than a century – until the airless tyre came along.
A design first thought up by French tyre maker Michelin, Bridgestone has now muscled in on the airless tyre scene.
Airless tyres bring a lot of benefits to pneumatic ones: you’ll never need to pump one and you’ll never need to worry about getting punctures again.
What is an airless tyre?
An airless tyre – called a Tweel by Michelin in 2005, a portmanteau of “tyre” and “wheel” – has a central hub assembly like a normal tyre, but has spokes radiating out from it.
These spoke are made out of an extremely tough but pliant material, mainly polyurethane.
A shear band is stretched over the ends of the spokes, and that forms the contact area of the tyre.
When driving, the spokes absorb road impacts just like a pneumatic tyre does.
The shear band and spokes bend and deform to absorb impacts, and spring back to shape once the bump has passed.
To vary the rebound rate, spokes of varying stiffness can be used, giving the car a softer or harder ride.
According to Michelin, its Tweel prototype gave “five times as much lateral stiffness as a pneumatic tyre” when tested on an Audi A4.
Bridgestone has also been developing its own airless tyre for use in industries where punctured tyres are a reality.
The farming, mining and construction industries are ideal use-cases for tyres like these, because airless tyres never leak or puncture.
What are some drawbacks of airless tyres?
Such tyres may be more maintenance-free than regular ones, but there are still several problems with them.
Debris could become trapped within the spokes, and the weight distribution is uneven.
The cost of producing these tyres is also prohibitive – they would need to be manufactured at scale to make financial sense, and that means the teething problems need to first be ironed out too.
Should I fit an airless tyre to my car?
Those benefits sound enticing, but alas, you can’t fit one to your car.
For one, no consumer-sized airless tyres are currently being developed, due to the problems mentioned above.
Even for major tyremakers like Michelin and Bridgestone, it’s still a huge task to manufacture something as complicated as this.
However, as 3D-printing becomes more advanced, we could gradually see them become more refined for consumer applications.
Right now, off-road, construction and military vehicles are outfitted with them, where the risk of a puncture could jeopardise mission criticality and comfort is secondary.
Wait perhaps a decade more, and surely you’ll be able to find one.