Wheels that don't puncture have been around for centuries
We don't use them because they are more shit than normal tyres for the majority of use cases.
Specific use cases, such as those faced by NASA may benefit from having such a feature, but to say they "invented" wheels that don't puncture is an outright lie.
The Superelastic Tire offers traction equal or superior to conventional pneumatic tires and eliminates both the possibility of puncture failures and running “under-inflated”, thereby improving automobile fuel efficiency and safety. Also, this tire design does not require an inner frame which both simplifies and lightens the tire/wheel assembly.
Except that NASA's new tires are actually better than normal tires in the normal use cases. Hence the word invented. Did you actually read the article before criticising it?
Traction is not the only factor. How does this new tire affect steering? How much noise does it make as it rolls on the ground? How much noise does it make as air flows over it at high speed? How durable is it? How does it handle high rotational speeds? How does it handle impact? How does it handle braking? How does it handle different weather and road conditions, different temperatures? How does it treat the road surface? And can it be manufactured at such huge scales? There are plenty of reasons why it might very well be completely unsuitable as car tires.
Wheels that don’t puncture have been around for centuries
What does that have to do with it? Those were a different design. Sure, this invention shares a couple of features with past inventions but that doesn't mean it's the same invention.
Most puncture proof tires are too hard. A good tire is soft enough to have a large flat area where it touches the road (or some other shape, if the road is bumpy).
There are plenty of tires that are puncture-proof. But they all have other major downsides. They're all a different combination of expensive, loud, uncomfortable, and unsafe. That's why none of them ever caught on beyond some specific applications.
There's almost no way bare metal gives the same traction as rubber tyres do. They say it does, but I'd need some really solid data to back that up, for all conditions that the average car will face, not just lab controlled perfect conditions. Tarmac, dirt, snow, rain, heat, cold, etc.
Also one thing I don't see mentioned is noise pollution. As cars go electric, more and more so the main source of noise from cars becomes their tyres. It's weird but true. Think of a motorway and how loud the sound of all those tyres rolling is. These would have to be quieter than rubber tyres to be viable.
Also there's no mention of cost or metal fatigue/wear. Rubber tyres are likely much cheaper to produce - even accounting for economies of scale, they use far less exotic materials.
And I'd be curious how long these tyres last vs traditional tyres through use and wear, how their characteristics such as traction change over time, how they handle hitting debris on the road, be it bits of rocks or whatever. The things cars contend with here and there regularly.
So, while this technology is potentially very promising in a hybrid tyre (like the bicycle tyre shown in the article, Vs the full-metal tyre shown), I have my doubts that need quelling before I see it going anywhere in its full metal state for general use. Specialised, maybe.
I'd love to find something that can replace rubber, and importantly be quieter, and maybe this avenue of research can lead to some great results. I just have my doubts that we're there yet.
Road wear might also be a concern. If it's similar wear as a traction engine trundling down the road, the wear might make it unsuitable for most roads.
Maybe they could be dipped in some kind of sustainable rubbery stuff, and when that wears down it’s stripped off and re-dipped. Sounds kinda energy hungry but who knows.
Seems exactly what the KickStarter that's trying to commercialise this to bike tubes is set out to do. Very interesting tech, but their attempt to appeal to reduce rubber waste falls kinda flat (pun intended) when these new tires require "retreading" their rubber rings
This won't work for high-speed vehicles, though. Not yet anyway. So it might be good for bicycles and wheelchairs and such. But the tires of cars and trucks generate a ton of heat from friction at high speed. And that friction is necessary for obvious reasons (traction). The high temperatures disrupt the "memory" of theses. So either they need to be made of materials that can work at higher temperatures which usually means they need to be manufactured at high temperatures that the manufacturing machinery then needs to be designed to operate at by making it from materials that operate at higher temperatures which means manufacturing that at higher temperatures and so on, or the need to make highly efficient insulation and traction layers that are thin enough that they don't affect the ability of the tire to deform and reform its shape.
You can change the Af temp, but it is not relevant in this case because they are using the superelastic properties, not the shape memory properties if Nitinol.
I question many aspects of this design for the consumer market, but not as you describe. Seems to me it's likely to be very expensive, and while you might not get flats it is still going to wear no matter what.
That's not true - one of the proposed use cases for these tyres is airplane landing wheels which are typically designed to work at up to 235mph. Aircraft engineers have to make major compromises to make sure they can land safely with a flat tire and when they get it wrong it ends really really badly. The concord crash, for example, was caused by a flat tire. Pieces of rubber from the flat tire flew up and punched a hole into a fuel tank. The jet fuel was on fire as it poured out of the rank creating a horrific fireball and the loss of fuel pressure caused two engine failures.
113 people died and the concord was declared unsafe since there wasn't any (affordable) way to redesign the aircraft to handle a flat tyre.
Sure - the wheels they use on the rover can't handle those speeds, but it could easily be modified to work. The bicycle tyre they demonstrated is a better example. It has a rubber coating which will heat up and provide plenty of traction if properly designed.
The real issue is weight. These tires would be too heavy.
I don't quite get the purpose of that bike tire. Tubeless tires are basically puncture proof aswell. I'd imagine that much metal just makes it unecessarily heavy.
Tubeless bicycle tires are often used with slime as otherwise they tend to leak from the edge of the rim as the pressure isn't usually high enough to create a perfect seal.
That also means they are effectively "self-healing" and puncture proof. Also tires that have this strip of goopy glue like stuff on the inside that seals all by itself are starting to get rather common as well.
Puncture resistant, not puncture proof. Tubeless sets with sealant can take multiple punctures before losing too much air ans/or sealant.
Also larger punctures don't get sealed by the sealant alone, but you need to fill the hole with something like rubber plugs
Puncture proof would mean that they can't be punctured or that puncture had zero effect
They keep calling it lightweight but aren’t saying what that weight is. It’s gotta be in the ballpark of a rubber tire to really be viable, so I’d say 4lbs at the absolute top end. More than that and it may reduce rolling resistance while shooting itself in the foot with the added rotational mass.
It's a fair point. Curiosity has "only" travelled about 20 miles over its 12 year life so far. And while it weighs some 900 kilos, Martian gravity is only 38% that of Earth.
Obviously it's absurd to compare the wear and tear on something rumbling around the Martian tundra cut off from any support or maintenance for a decade, but it is a very different use case to your average Earthly car or lorry. What lasts a decade going at 0.1mph for 20 miles in an alien desert is not necessarily going to last a week going at 70mph down an asphalt highway.
As of December 9, 2020, the rover was 23.32 km (14.49 mi) away from its landing site. As of April 17, 2020, the rover has been driven on fewer than 800 of its 2736 sols (Martian days). As of 30 May, 2023 it had traveled 30.00 km (18.64 mi).