AIRLESS TYRES

What a time to be alive. An expression appropriately used more frequently as the human race spits out new, advanced ideas, contemporary technologies and unique solutions. We are surrounded by luxury that our ancestors could never have imagined. Different concepts are popping up faster than anyone can keep up with.

An almost ancient item of luxury that is often overlooked is our old friend, the tyre. Tyres form an integral part of our daily lives, yet to most of us they go completely unnoticed. Tyres are different from brand to brand, of course, but most of them usually consist of over 100 different substances. One of the main components is natural rubber, but tyres also include synthetic rubber, steel, nylon, polyester, carbon black, petroleum, sulphur, etc. Each substance plays a critical role in the overall purpose of the tyre. A tyre cannot function on these components alone, however. An additional component, not part of the material structure but integral to the workings of the tyre, is air.

The wheel has been around since nearly the beginning of time and it has evolved from a solid piece of wood to a balloon-like structure. The added air provides a medium to allow expansion and contraction of the tyre regardless of what kind of material was used for making the tyre. Tyres are subject to extreme temperatures as well as large amounts of force. The air reduces the wear and tear caused by friction between the rubber and the rim.

The main disadvantage of air in tyres is, naturally, the air escaping the tyre. Via a slow-puncture, wear and tear, or brute force. The latter has proved to be extremely dangerous. A burst tyre on a rough road has claimed many lives.

In order to keep up with the “what a time to be alive” theme, Michelin Tyres jumped right in and went ahead and developed the first-ever airless tyre, called Michelin® UPTIS. UPTIS (Unique Puncture-Proof Tire System) is the manufacturer’s new airless mobility solution. It is difficult to explain the design. For simplicity’s sake: UPTIS has an outside rim of, basically, a “sheet of tyre” as well as an inner rim, also a “sheet of tyre”. Connecting the two rim sheets it uses reinforced plastic vanes or spokes (yes, think of a bicycle), bending or at an angle in the middle. These are highly flexible and allow for uneven surfaces.

Naturally, the main feature of these tyres is that they will not have punctures or “flats”. Sidewall cuts are a thing of the past. No need to check your tyre pressure. And no more spare tyres. A future benefit includes less tyre production because fewer will be damaged, thus fewer tyres will be consumed. This might counter the fact that per UPTIS tyre more material will be needed as it is no longer one giant air bag but includes the “spokes”.

Enormous potential, of course, with imaginable and unimaginable obstacles and solutions.

Nevertheless, the idea is there and patented, and it can only be improved from here on out.

Here is a fun fact about tyres that not everyone is aware of. Did you know that you cannot bury a tyre? Or rather, you can physically bury it, but it will not stay buried. A tyre will always resurface, even if it takes a few years. In fact, many countries have made it illegal to bury tires as they pop up again in a few years’ time causing damage to structures built above it.

Why does that happen? Tyres are a very odd shape. They have a large volume and a large void space in which they tend to trap air as well as methane gas. The trapped air and gas cause the tyre to constantly push back on the soil surrounding it. The pressure above the tyre is significantly less than the pressure below it and so, over time, the tyre simply pushes itself back onto the surface. The only way to ensure this does not happen is to shred the tire into smaller pieces.

Now the question is: would an airless tyre be the same or is there yet another benefit to this new design?

Theoretically, the void area of the tyre is smaller in total volume (as more space consists of physical material). However, it contains a lot more smaller voids. Will they be easier to fill and will it thus be more difficult for air/gas to be trapped in them, rendering the tyre buriable? Or will the voids make it more difficult to fill, thus creating more spaces for the air/gas to be trapped within, and therefore cause the tyre to resurface over time like the current customary design?

Only time and physical experimentation can tell.

For now, though, have a look at Michelin’s website, michelinmedia.com/michelin-uptis, for more information as well as a video demonstration.

Daniela Steenkamp