Michelin Rolls Out an Airless Tire That Will Be “Puncture-Proof”
caranddriver.com
caranddriver.com
1. weight. anything thats supposed to handle interstate speeds and offer comfort is going to be heavy as it will need to be durable. id be surprised if these tweels show up with the longevity of a standard all-weather radial. Id be even more surprised if drivers dont pull into the service station for more esoteric repairs like CV joints, brakes or idler/pitman assembly changeouts as this is common in vehicles that upgrade to more rugged tires.
2. partial failure. Most people dont want to spend money on a new tire if its 40% worn and a hole or cut is in the tread. Typically a bubblegum type or kevlar patch is applied for $30 to the tire, which keeps it rolling intil its worn enough to replace. How do you repair a tweel thats received curb strike damage or a sharp object?
For those who have pointed out, yes, fork trucks and fork lifts commonly use solid tires, but thats largely due to how they work. Many forklifts can hoist in excess of 40 tons, so it makes sense to have a tire that doesnt readily compress. Its why big trucks have to have more tubeless tires for larger loads. The plastic or rubber tires on forklifts also have a quick re-tread option. The tires often dont even need to be removed, as they have more treads that can be created by pulling out zip-tie like spacers in the worn tread. other models use a hot-iron type re-treader. that being said, forklift tires are very heavy and so are the wheels, and neither last very long at full-speed.
Wow, that's clever. But it does make me ask, tread is AFAUI for dealing with water on the ground, and I guess also when the vehicle's going at speed.
Forklifts AFAIK operate mainly indoors, and even then they never get up to any speed that I've ever seen, so why treads at all?
you can order treadless tires as well.
(Weight is much more obviously and directly influential in an EV's mpkwh/mpge than in an ICE vehicle's mpg. Brags about weight savings are huge in the EV sector, including cars advertising even the rolling weights of their tires versus their competitors.)
This looks like a different structural fin design, so maybe they’ve fixed the noise issue, but you still have an open sidewall to fill with mud, ice, rocks, etc...
> "If you have a load on the tire and you cut all the spokes at the bottom, you will see that nothing will change, demonstrating that the load is carried by the top of it, not by the under parts." Other airless tires, he said, often carry the load at the bottom of the tire, which is very inefficient and causes extra heating due to compression.
Tires like these already exist for industrial equipment, Michelin does need to address these very real concerns. I am also concerned about the ecological impacts, it appears the tire uses more rubber than conventional tires, the only way this isn't worse is if it is safely recappable. It may be, but again the article doesn't state so.
"Although it is acknowledged that the initial prototype automotive Tweel tires did demonstrate flaws with regard to noise and high speed vibration[5] and produced 5 percent more friction compared to a radial tire,[3] these early issues were resolved in subsequent prototypes, and current automotive Tweel prototype products have been shown to be well behaved and reliable."
My guess is it'd keep the air in which you don't want with an airless tire.
Just add a valve that allows air out if the interior pressure rises more than x% above ambient atmospheric pressure, and allows air in through a filter if it's more than y% below. It wouldn't be that much more complex than the stem valves already added to tires.
The primary goal is to keep contaminants out of the interior tire structure, but a secondary marketing goal should probably be to make them look like normal tires at first glance. Wrapping the internal structure in something that looks like "normal tire" serves both.
One of the nice things about a pneumatic tire is that you can air down if you need low ground pressure. I guess that goes out the window too.
These will probably work really well in some use cases but barring some massive groundbreaking improvement I wouldn't expect to see these replacing conventional pneumatic tires over the next decade or two.
Edit: I'm talking about these tires in the general case, not specifically as they exist on a Bolt.
Interestingly, there's only 845lbs wiggle room on these tires as installed on the Chevy Bolt assuming the standard Bolt configuration at 3,563lbs and the carrying capacity of the tire at 1,102lbs. After accounting for your average American family of four (or just the weight of two men and two women) at 728lbs, you're left with 117lbs for the fifth person or belongings.
...so even if they're prototypes, I hope they've been over-engineered. That said, I want them to succeed.
In showroom configuration 99.99% of vehicles are only spec'd with tires that barely exceed the GWVR.
That said, with a pneumatic tire you can just air it up higher than the OEM tells you to and you're good for more GVW at the expense of the tire wearing faster. Obviously you need to be reasonable about it but tires are pretty durable even over their stated weight rating as long as you don't run them hot (airing up reduces flex therefore reducing heat).
It will be very interesting to see if they come out in other sizes/capacities. They already make similar tires for off road use but they aren't suitable for road speeds (go figure)
[0] https://gm-volt.com/forum/showthread.php?276641-What-is-Bolt...
Imagine the disaster a much longer tread life on this tire would be to Michelin and tire shops. Even if Michelin could maintain their profit with proportionately higher prices, tire shops would be hammered by a long life tire.
I'm not claiming that such a tread is out there and being suppressed. But if it were a plausible but expensive engineering problem there would be a great incentive, especially by market leaders like Michelin, not to pursue it.
But wouldn't it be wonderful to buy a car with tires that are expected to last as long as the rest of the car. I can dream.
Kodak lost out (even though they were one of the first with quality high resolution sensors) because they didn’t want to cannibalizes and threaten their cash cow (and legacy or patrimony).
Then you have that many cars now want you to replace at minimum 2 tires and not just the one that has been punctured.
Never the less, it was my impression that re-vulcanizing tread doesn’t affect the integrity of the tire structure (wall, casing, belts)
Maybe they would be okay on things like kei-cars?
In the real world retreads are more likely to be under inflated because they are likely to be used on a trailer not the truck, which is in general not inspected as often as a truck. Truckers use the same truck for the most part so they take care of it, while they hook up to different trailers all the time.
Retreads are also older tires. Retread doesn't affect the integrity of the tire structure, but sunlight, air and water does. (water only once there is a small track to the steel belts). These are all a function of time, and retreads are always older.
The above is what I can gather from a search, but it does seem like most of the information is written by retread marketing so take it with a little salt.
"... when we make the remolded tire we remove the existing rubber down to about 3-6mm remaining on the recycled casing. The rubber is removed from the inside bead, across the sidewall of the tire, across the tread of the tire, all the way to the outer bead. We then replace the rubber from "Bead-to-Bead" applying 6mil rubber on the sidewalls and multiple plys of rubber on the tread."
They probably do some kind of scan to determine the structural integrity of the tire structure, I imagine.
Google "nhtsa retread study" if you want to learn more. It covers truck tires but (other than cost) there's nothing fundamentally different between those and smaller road tires.
For road car usage, I'd be more concerned about dry rot and aging tire issues from age than anything else. New car tires are cheap. We drive about 5-6K miles per year per car. We change tires based on calendar age about as much as treadwear.
So say two Toyota’s with oem Michelins, one is replacing a whole set due to wear, the other needs one replacement of otherwise healthy tires. Replacing a set of 4 is ~500. Re-vulcanizing tread on one (from the worn out tread set)might be less than buying a pair of new ones or a set of new ones (some dealers will not sell you a single tire)
If intentional, bravo.
Mass produced, and economies of scale take over, and a resin with carbon fiber, or some other high performance composite gets cheaper, and ultra durable donuts get popped onto car rims around the world.
At least locally this has already happened. I just got new tires for my truck at a place named Tire something or other. Since I was there I got an oil change. I also have a leaky head gasket (110k miles on the truck) they said they could fix it then or I could just do it at my next oil change.
Do you get shops in the US that do nothing but tyres?
I think you also have shops that just do oil changes?
Why split all these jobs up? In the UK I take my car to one shop, once a year, and they do it all in a couple of hours.
Oil changes places are setup to make oil changes fast and easy: there is a pit in the floor, and someone in there at all times. When you pull for your oil change he has the right wrench on your engine almost before you turn it off, and is only waiting for "go" to start letting the oil out. The guy on top is meanwhile looking up the oil filter (which they have in stock: they turn inventory fast enough that accountants don't worry about this cost) and how much oil to put in. When the oil plug is replaced below the guy on top has a machine programmed to put the right amount of the right oil in. The result is they can do your oil change in 10 minutes with 2 low skill employees and they make less mistakes since the machines are programmed to prevent them.
Compare to your mechanic: he needs to jack your car up (he has a power lift not a pit), then move the drain pan into place. Then one the lower end is done jack it down, call the warehouse to deliver the right filter for your car, then look up how much oil to put in and open the cans and count. In the end your mechanic ends up spending more man hours than the oil change place and is more likely to make a mistake because less is automated. Your mechanic is also more expensive because he knows how to do other work and has tools for that, you pay for all those tools and knowledge even if you don't use it.
That pit in the oil change place is very dangerous (exhaust buildup, people falling in), engineers have spent significant effort figuring out how to make then safe. That pit is also expensive, if use it for 30 oil changes a day, 6 days a week, for 10 years the cost is pretty cheap per use. If you are a mechanic working on general repair not only is a lift cheaper and safer, the ability to position the car at any height make it more useful: if you have a both you will often choose the lift making the cost of the pit something that is amortized over less uses.
Similar applies to tire changes: they need some expensive specialized equipment that your mechanic isn't using but still needs to pay for. The tire change place has more tire customers to amortize this with.
Note that the above specialization works because oil changes are tire changes are common enough that it is worth the effort to make it work. Your town doesn't need to be very big for there to be enough cars to support many specialized oil change and tire shops. This quantity of shops means that engineers who design specialized tools have a large number of potential customers to split the R&D cost between making the costs lower. Tires and oil are all similar enough between cars that one machine can handle most.
As we get out of the common repairs we get to one off: most engines don't need a head gasket change anymore, for 200 million dollars I can design a special tool to do the job much faster: labor might only be $20, but your share of the tool R&D is $1 million dollars since only 100 people will replace the head gasket for that type of engine. Or you can pay a mechanic to do it without the tool, your labor is $800 but not special machine to pay for. Of course if your engine turns out to have a common problem things will change: mechanics will develop tricks to do the job faster, maybe some tools will be made, but it will probably never get as cheap as the machine I envisioned.
All those things need doing once a year at most. Drive to one place, have it all done at once.
Any company, including the market leaders would instantly make billions with a cheap long lasting tire and would render all competitors as obsolete. All other tires would become buggy whips in comparison...
So, why would they suppress that?
It would be a more obvious good deal for a smaller tire maker who has more market share to gain. But they're less capable of sustaining a huge R&D budget. I just hope the solution isn't that expensive.
From Michelin's perspective they would have a golden goose of a product and would want to exploit that for as much profit as possible...
Also, they're not just going to gain market share they would literally be the market-leaders in a new industry of long-lasting tires...
They had a technological lead, but were afraid to cannibalize and threaten their cash cow (film). In the meantime others with less to lose, jumped in and eventually took over the market and Kodak became a shell of its former self. Point being, it's not unheard of for companies to be slow to adjust to a new realization.
And in the film category, Sony owns blu-ray. Cannibalisation is a real reason not to pursue certain ventures. Blu-ray sales in 2014, when netflix was already established as a streaming service, were still above $25 billion. At the time it might have been deemed a poor investment to try compete with your own physical sales by creating another streaming service. Keep in mind Netflix doesn't even turn a profit in the billions these days, yet a declining blu-ray still makes more than $10 billion a year.
So I'm not sure outmanoeuvre is the appropriate word just yet, perhaps in time it will be, but Sony might still think its choices were the better ones and I'd probably side with them.
For the record, Netflix is now worth about an order of magnitude more than Sony. Should Sony have tried? Maybe. In a lot of ways they were better equipped to try but they didn't and now someone is gaining a disproportionate share of global eyeball time
Still 3x is pretty impressive, and it's still disappointing (IMO) that Sony failed to launch a relevant streaming service given their expertise and interests.
I'm honestly happy if they last the same length, as long as I never need to worry about running on a flat - even just getting the damned tired pressure sensors calibrated correctly turns into a day or two of effort.
Long treadwear tires tend to have terrible traction qualities as compared to softer tires. This is obviously true in motorsports (and is a major strategy component in Formula One), but is also noticeable on road cars. It's not just sports cars and "racer wannabees", but handling traction is a safety issue at the limit. For winter tires, you typically need a softer and more compliant compound as well.
You could make tires out of something closer to cast iron that would wear incredibly long but have terrible traction and ride.
Exactly.
If you throw load range E truck tires on your compact SUV they will last until they dry rot, so a decade or so. People buy milsurp Goodyear MTRs and run them on pickups/SUVs and they last practically forever on lighter vehicles. Neither of these will do good things for handling though.
The tire OEMs could make a tire that lasted 100k and provide "tolerable" handling in normal conditions if they wanted. They don't want to because in this day and age anything that obviously trades safety for reduced cost is basically a non-starter and they don't want to get sued into oblivion.
>You could make tires out of something closer to cast iron that would wear incredibly long but have terrible traction and ride.
"sheepsfoot wheels" is the term you're looking for.
And besides, modern tires last 50k miles. That's twice around the planet by friction force. That's not enough of an engineering marvel for you folks?
With regards to these tire replacements, the questions that occurred with previous look a likes are still on my mind. How do they keep the open and compressible areas free of debris, if not snow during those months, and what effect does the debris that are not dislodged have longevity and safety?
Since sidewalls impart a lot of strength how do these tires perform during harsh maneuvers. Are they strong enough side wall wise for racing? Some tread compounds are sticky enough on production tires to allow cars to pull more than 1g forces laterally.
Even if they reduce the need to replace them as often, there are already tires that pull in excess of fifty thousand miles, I doubt they will be that radical. The softer summer compounds are not being discussed here and those are popular on many sports cars and non traditional sport vehicles
Tire design (and purchase, for an informed consumer) is a compromise between price, grip, wear, and conditions (temperature, rain/snow/mud/etc).
My friend buys tires that last him ~7+ years, which for him is a lifetime of the vehicle. But if a kid ever jumps in front us on the street, I'll rather be in my summer performance tires that last me ~3 years (or less if I have fun:).
The problem is that you will not like the tradeoffs.
This is vastly oversimplifying, but the overall tradeoff is grip vs durability.
You get a very grippy tire made for racing in series that mandate street tires, and these will typically have both a very sticky compound and low tread depth. They perform great, but may last less than 15K miles of street use (or less than 20 miles on the racetrack).
On the other end, you can get what are essentially hockey pucks that'll last a very long time in normal highway use.
Depending on what you want to optimize for, you can start with several ratings on the tires themselves. Tire Rack has a great guide here [1] on treadwear and traction grades. It is a good place to start, and then you should always seek more detailed knowledge from people with direct field experience, as the ratings can be a bit games (e.g., you'd want to get some kind of AAA-traction rated tire for an autocross or track day, but getting the best one for your car, driving style and that event it'd be best to also talk to/read articles by people who've been there & done that)
[1]https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=...
Airless tires have been obsolete for over a century, but crackpot "inventors" keep trying to bring them back. They are heavy and slow. They give a harsh ride and poor high-speed cornering on rough surfaces. They are also likely to cause wheel damage, due to their poor cushioning ability. A pneumatic tire uses all of the air in the whole tube as a shock absorber, while foam-type "airless" tires/tubes only use the air in the immediate area of impact...
> Unlike past attempts at airless tires, Uptis functions the way other modern tires do and, Michelin claims, will provide a similar driving experience.
And I doubt Michelin is leaving this up to "crackpot inventors".
Hard ride, bad traction, pain in the royal butt to service or install...i don’t see these things changing just because the tire’s on a car now.
i predict we hear nothing else about this design.
I will of course be happy to be wrong!
But whether it provides enough durability, traction, and a smooth riding experience is unclear. I'm rooting for them. Michelin definitely aren't crackpots.
Even regular run-flat tires seem to make wheel damage more likely. My car came with run flats and had multiple bent wheels over time, but I haven’t had any issues since I replaced them with normal tires a few years ago. Dramatically smoother and quieter ride as well. Lacking a spare tire I put some fix a flat and a 12v inflator in the trunk and hope for the best...
I’m a bit confused by this. Is the resin-embedded fiberglass that Uptis uses to make this possible in the tire or is this a new hub that makes the airless tire possible?
Unrelated:
> max load of 1102 pounds.
I have to assume this is per tire considering the Chevy Bolt weighs 3,600lbs but it's not clear from the article.
The added inertia would provide more shear stress in the rubber to get the tire accelerating. That could have a lifetime affect due to crazing in the polymer/fiber network (which can be especially prone to failure due to interfacial failure between the solid fibers and polymer matrix).
Full disclosure: I say this as someone who knows next to nothing about tires/tire pressure/cars in general. My tire pressure light has been on for at least three months now.
Maybe worth getting that checked?
From https://www.theaa.com/driving-advice/safety/tyre-pressures
"Under inflated tyres will increase stopping distances and affect your vehicle’s handling so that collisions are more likely; Under inflated tyres will flex more and get hotter, making sudden tyre failure – blowouts – more likely; Under or over inflation increases tyre wear so you’ll have to buy new tyres more often; Under inflation increases your tyre’s rolling resistance which means higher fuel consumption"
Your assumption is correct. Tire load ratings are per tire.
Our van had a tire slashed at a church parking lot that was renting space to the high school under construction. It didn’t collapse until after a 5 minute drive was completed when it was (thankfully) at rest. Exploding tires on the highway at 70 MPH aren’t fun to think about.
Absolute nonsense. Airless tires have been around for about that long also. I've seen airless motorcycle tires from circa 1920 in a museum: they looked a lot like that picture of the new one: basic hub shapes with lateral voids in them.
They are in use currently; I've seen them from time to time over the years on various earth-moving equipment around town.
The idea of airless tires for general motorist use gets periodically trotted out by snake oil salesmen as some new revolutionary thing that will take over the industry.
Pneumatic tires have superior performance because the entire volume of air around the wheel provides the suspension and shock absorption, rather than just the compression of a small amount of material around the contact patch.
In 20 years of driving I can count on one hand how many times I’ve gotten a flat of any kind and none of them were bad enough that I had to immediately pull over. It’s also not like I only drive 5 miles a day, I easily beat the national average in regular usage and have taken multiple 2+ month long road trips covering 10k miles at a time.
For me the value just isn’t there, but I suppose there are people who have had dozens of flats? I mean they have to exist for a reason, right?
https://www.schwalbe.com/de/pressereader/weltneuheit-schwalb...
However, if I recall some reviews correctly, it is quite complicated to install.
This isn't quite the same, but in calling it the "first airless system" it sounds like they had done zero research on previous systems and have no idea what the potential problems are.
The new Michelin system is a rather different concept. I dunno if it will adapt to bike tires or not, but it would be great if it can.
I'm kinda surprised they didn't go for something like a gyroid mesh.
Car makers expertise at making cars is often pretty bad their expertise with electronics and software security is hilariously bad.
A universal remote kill switch is a very bad idea especially in response to a tire that might be in production for a tiny fraction of cars 5 years from now and with a wildly successful and unlikely uptake could be pervasive in merely decades.
Given motivation I'm sure people can probably figure out a low tech solution that does not involve figuring out how to fit all cars going forward with a backdoor that will almost certainly be exploited.
For example perhaps something could damage or foul the wheel or clamp onto it.