Michelin and General Motors are teaming up trial a crazy airless tyre concept on the Chevy Bolt EV. The new tyre is just a prototype at this stage, but Michelin is working to make it a reality, trials start later this year and have a goal of making Uptis a mainstream reality on passenger vehicles as early as 2024.
Announced at the Movin’On Summit for sustainable mobility today, the Uptis Prototype (or “Unique Puncture-proof Tire System”) could see the end of the spare wheel entirely and a reduction of vehicle accidents as a result of blowouts.
The structure of the wheel is completely different than normal road tyres. Traditional tyres use a rubber surface on the exterior with tyre tread designed in a way to disperse water and enhance grip. This is reinforced structurally with steel belts to help it hold the shape and combined with a stiff sidewall, an air chamber is created and pressurised to dampen bumps in the road.
The tyre design works great until you run over a nail or sharp object that allows that air to escape. Should this deflation occur rapidly, or the tyre structurally fail, it could result in the driver losing control of the vehicle. For anyone who’s had a puncture, it’s not only inconvenient to get it fixed, but also can be expensive.
The new Michelin design rethinks the whole tyre design, instead of using air, it uses a sequence of stiff rubber segments, designed specifically to structurally support the weight of the vehicle. These work in a similar way to the springless trampolines that are around now. Under the right conditions, it allows the flex in the tyre to absorb a bump and bounce back.
With no air, there’s no risk of a puncture and that’s dramatically demonstrated by the video released with the announcement. This shows the tyre running over a serious of nails, the nails penetrating the outside layer of the tyre and the car continuing effortlessly. Sure there may be a hole in the surface of the tyre, but the structure is maintained.
This introduces the possibility of eliminating the need for a spare tyre all together. You’ll notice in newer cars there’s a trend to add a space saver instead of a full sized-spare. If you’ve ever had to use one, you’ll be familiar with the annoying 80km/hr speed restriction, but hey at least that’ll let you limp home or to the next tyre repair shop. These repairs can be hundreds of dollars, particularly if you need it replaced.
Importantly any spare tyre is going to add unnecessary weight to the vehicle and therefore reduce your fuel or energy efficiency.
Some people have raised issues about the lack of a sidewall and the potential for mud, snow and other objects to get stuck in the tyre. This would create an unbalanced tyre which could oscillate and destroy itself or the suspension. At best it’d be a rough ride at worst it could seriously damage your car.
In reality, I suspect this prototype version doesn’t have a sidewall to show the internal workings of the new design. Once this reaches production-ready status, they’ll work out a semi-flexible surface to wrap the side of these tyre and they may end up looking very similar to conventional tyres.
“General Motors is excited about the possibilities that Uptis presents, and we are thrilled to collaborate with Michelin on this breakthrough technology. Uptis is an ideal fit for propelling the automotive industry into the future and a great example of how our customers benefit when we collaborate and innovate with our supplier partners.”Steve Kiefer, Senior VP, Global Purchasing and Supply Chain, General Motors.
One of the proposed benefits of this tyre is its ability to last longer than a normal tyre. The theory being that you won’t suffer from over or under inflation, therefore reducing the ability for internal or external edges to wear faster.
That theory may be just that, as one quick shot in the video, shows the wheel in action and its clear just how much additional contact surface is on the ground, this is easily triple and possible four times the amount of surface area as traditional tyres.
Having larger contact patches on the road is generally a good idea, especially in tricky conditions, but more contact equals more wear, there’s no way around that. Also driving in a straight line is one thing, but with much more contact to the road, these new Uptis tyres are likely to wear as the driver turns the wheel, essentially dragging the leading or tail edge across the road surface.
All things considered, it’s neat to see tyre innovation arriving. Michelin are no stranger to airless tyres, having already worked on an ATV version a couple of years ago. The big progress here is that move into the consumer vehicle support and now the big question becomes how many situations will these work for and how much of a premium (more material) will these cost?