Re-inventing the wheel

November 8, 2005 12:16 PM

In 1844, Charles Goodyear invented vulcanized rubber. In 1845, Robert William Thomson invented and patented the first vulcanized pneumatic tire, although his design was too costly to be practical. John Dunlop patented his own design for pneumatic bicycle tires in 1888, and this design was less expensive to produce than Thomson’s, and was widely adopted. André Michelin attempted to make the first pneumatic automobile tire in 1895. Although his initial design was not successful, he persevered, and the company he formed with his brother Edouard flourished. And although the tire has continued to evolve, its basic form -- that of a torus filled with pressurized air -- has remained unchanged for 160 years.

While pneumatic tires provide a ride that is both comfortable and safe, the fact that they are filled with air creates some obvious problems. But what if you could make a tire that had the ride characteristics of a pneumatic but was not, strictly speaking, a pneumatic tire? In an interesting attempt to "reinvent the wheel," Michelin has developed an airless tire they are calling the "Tweel". This press release has the standard yadda yadda you would expect with any new product announcement, but these pictures on a third party site demonstrate what a radical idea the "tire without air" really is.
posted by mosk (37 comments total)

I remember reading this press release when it first came out last winter. Have these been released yet, or is any new information available? Googling just brings up the old press release.

It's really an interesting design. They sound really cool, although they look pretty ugly to me.
posted by ducksauce at 12:22 PM on November 8, 2005

> spike strips will definitely be ineffective with a set of these....

Ha. All you need is to pop the spikes up from the side to hook the tires. Imagine the police wanting to stop a vehicle with these on the fly -- say by throwing a steel rod through these from the side -- ever had a bike tire jammed by a stick?

Even getting a big rock caught in one of the spaces, while driving on an unpaved road, could be rather jarring
posted by hank at 12:27 PM on November 8, 2005

I would imagine the production models would have closed sides.
posted by Pollomacho at 12:29 PM on November 8, 2005

They should make them for BICYCLES, dammit. I get so tired of fixing flats or replacing tubes because rude morons keep breaking glass bottles on every flat surface they see.

Though I agree with Hank: I think the spokes on these tires, as well as those on bikes, should be covered.

And is "torus" Latin for "donut"?
posted by davy at 12:31 PM on November 8, 2005

That's really neat-- I hadn't heard of such a thing. They may well render the blowout a thing of the past. Of course, if they last, say, four times as long on average as a pneumatic tire, then I'm sure they'll cost five times as much, but I suppose that's the price you pay for progress.
posted by Faint of Butt at 12:35 PM on November 8, 2005

Very cool but I'm having the strangest emotional reaction to seeing them..it's almost fear. For some bizarre reason I can't get my mind to trust them.
posted by spicynuts at 12:36 PM on November 8, 2005

Does it create obvious problems? The pneumatic tyre has the advantages of being light and very low rolling resistance. So what if you get a puncture now and again? The joys of rolling on a really good set of tyres more than make up for it — and make sure you check your wheels for damage every now and again.

Higher mass/rolling resistance in car tyres will damage fuel economy. Exactly what we don't need.
posted by scruss at 12:37 PM on November 8, 2005

then I'm sure they'll cost five times as much, but I suppose that's the price you pay for progress.

You have to also figure in the fuel savings from having your tires ALWAYS at the appropriate 'pressure' so to speak. I think it was Consumer Reports that indicated incorrect tire pressure is responsible for up to 3% loss in fuel economy. Over several years that could really add up.
posted by spicynuts at 12:38 PM on November 8, 2005

Higher mass/rolling resistance in car tyres will damage fuel economy. Exactly what we don't need.

From the press release:
The Tweel prototype, demonstrated on the Audi A4, is within five percent of the rolling resistance and mass levels of current pneumatic tires. That translates to within one percent of the fuel economy of the OE fitment.

So there you go.
posted by Faint of Butt at 12:42 PM on November 8, 2005

Heh. These are pretty similar to some moon-rover wheels that Arthur C. Clarke described offhand in 2001 (I think). I've always wondered when something like that would go into production.
posted by COBRA! at 12:45 PM on November 8, 2005

Bummer they weigh as much as normal tires, from the looks of them without sidewalls or steel construction, my first thought was that they could be 1/10 the weight and really make strides towards better fuel efficiency.
posted by mathowie at 12:54 PM on November 8, 2005

They really should put sidewalls on production models. As someone who bikes and drives offroad frequently, I can only imagine the extra debris flinging power of all those open spokes.

And while these are pretty damn cool, what I really want is a set of applied-nanotech smart wheels like in Neal Stephenson's Snowcrash. 100 MPH on a skateboard over debris and terrain? Stairsteps, obstructions and other obstacles effectively rendered as smooth planes through the magic of hundreds or hundreds of thousands of intelligent, active footy things? Power generation and integrated motorization in one wheel? Fuckin' righteous.

But for now I'll take a set of tweels for my bike. I've got a slow leak in my back wheel as it is right now. Can I come pick up a set tommorow?
posted by loquacious at 1:20 PM on November 8, 2005

spicynuts - You have to also figure in the fuel savings from having your tires ALWAYS at the appropriate 'pressure' so to speak.

I wonder how well the spokes resist material fatigue. Could be that as time goes by the 'pressure' drops? They might not last as long as a conventional pneumatic tire/tyre.

I also wonder about whether the fatigue is linear or non-linear.
posted by PurplePorpoise at 1:20 PM on November 8, 2005

As an aside, my grandfather apparently developed an early form of the tubeless air-filled tire that the whole family claims was stolen, patented, and made certain people very rich.

It's long past his death and any more available information, but I wonder if some of these people got rich from what my grandfather created.

(If anyone is interested, his name was Walter Hansen)
posted by Kickstart70 at 1:21 PM on November 8, 2005

Those are ugly but can you imagine them with plastic Pep Boys spinners? Hell yeah!
posted by evilelvis at 1:25 PM on November 8, 2005

er, does anyone thing that compressed air doesn't contribute to vehicle weight?

Hint: it's compressed.
posted by clevershark at 1:27 PM on November 8, 2005

I wonder how well the spokes resist material fatigue.

Yeah, particularly after I drive with them in winter in NYC and make sure to hit every freakin gigantic pot hole on the BQE. Cuz my old fashioned air tires? They no likee too much.
posted by spicynuts at 1:31 PM on November 8, 2005

And while these are pretty damn cool, what I really want is a set of applied-nanotech smart wheels like in Neal Stephenson's Snowcrash.


loquacious - I had the same thought when I first saw these, which is one reason I decided to make the post -- they reminded me of those wheels from Snowcrash. The promise of further development is also very intriguing -- lighter/better/stronger/etc. Think of the major advances in tire development: tubeless, belted, radial, and think what this sort of design might morph into after a number of years (assuming it is, in fact, a safe and viable design). These may never actually hit the streets, but it is good to see that this sort of research is ongoing.
posted by mosk at 1:34 PM on November 8, 2005

You can get "airfree" bike tires (see for example here), but they're really not very good. Airless bike tires are hard to do because they are so very narrow. In the words of the immortal Mr. Brown:

Airless tires have been obsolete for over a century, but crackpot "inventors" keep trying to bring them back. They are heavy, slow and give a harsh ride. 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.

Airless tire schemes have also been used by con artists to gull unsuspecting investors. My advice is to avoid this long-obsolete system.

posted by bonehead at 1:35 PM on November 8, 2005

What did the lunar rovers use for tires? Was it something like this?
posted by fandango_matt at 1:41 PM on November 8, 2005

I'm sure I've seen tires almost exactly like this, on toy RC cars by Tyco or some such. I know I've seen them before somewhere, and quite some time ago at that... hmmm...
posted by C.Batt at 1:45 PM on November 8, 2005

The spokes can be engineered to give the Tweel five times as much lateral stiffness as pneumatic tires without losing ride comfort.

wow.

What did the lunar rovers use for tires?

AFAIK, thinly-spaced steel/metal cylinders to basically paddle through the dust.
posted by Heywood Mogroot at 1:48 PM on November 8, 2005

Given the ridiculously short sidewalls on some of the 20"+ wheels the kids seem to all love so much these days, it's more likely that we'll see just a plain strip of solid rubber wrapped around a 30" wheel before we're going to see something like the tweel (what a grating word) in production.
posted by mr_crash_davis at 2:04 PM on November 8, 2005

shakes fist at kids these days
posted by Kwantsar at 2:16 PM on November 8, 2005

What did the lunar rovers use for tires?

AFAIK, thinly-spaced steel/metal cylinders to basically paddle through the dust.

The early russian rovers (Lunokhod), yes.
The NASA rovers used what looks like pneumatic tires.
posted by spazzm at 2:20 PM on November 8, 2005

clevershark: does anyone thing that compressed air doesn't contribute to vehicle weight?

Of course it does, but it's very, very little - about 13g by one estimate. If one's goal is to reduce unsprung mass / rotational intertia / vehicle weight, this isn't the place to start looking, methinks.
posted by Western Infidels at 2:32 PM on November 8, 2005

Pneumatic tires on the moon rover? With no atmosphere? Nuh-uh.

From nasa.gov : "Tires of spring-steel wire mesh carried treads of titanium-alloy chevrons for traction; "bump stops" inside the wire mesh prevented collapse of a tire in case of severe shock."

Think wireframe donuts.

Speaking of donuts, what are these Tweels going to do for Drifting?
posted by bartleby at 3:00 PM on November 8, 2005

its basic form -- that of a torus filled with pressurized air -- has remained unchanged for 160 years

errr. right. and you'll you know the future has finally arrived when pneumatic tyres are triangular and filled with pneum...
posted by andrew cooke at 3:08 PM on November 8, 2005

Aha! I counter your FLAT TIRE / CREVÉ play with PUNCTURE-PROOF TIRES / PNEUS INCREVABLES! Coup fourré! Now I can put down 200 miles to reach Mille Bournes!
posted by purple_frogs at 3:27 PM on November 8, 2005

Speaking of donuts, what are these Tweels going to do for Drifting?

Actually, I'll bet that's a primary driver for this technology. With pneumatic tires, the contact patch lags behind the wheel rim by a slip angle because of the flexibility of the sidewall. This angle is dependant on load, steering force, tire pressure and speed - so it's difficult for suspension designers to accomodate. That's why "low profile" tires are popular. I imagine the transverse spoke in this design would work to reduce the slip angle, and thereby improve handling.

Here's what's bugging me: I can't figure out the load path of these tires. Pneumatic tires "hang" use air pressure to keep the tires from collapsing while the rim hangs from the top. Judging by this picture, these wheels also hang from the top ( the lower "spokes" appear to be buckled). So how then is the bottom part of the tire kept from folding upwards? Does the tread surface encase a giant hoop spring? If so, I bet there's a significant weight penalty.
posted by Popular Ethics at 3:49 PM on November 8, 2005

hehe purple_frogs

It's be interesting to see how those things stand up to Montreal's notoriously awful roads.
posted by clevershark at 3:50 PM on November 8, 2005

Ah Mille Bournes! One of my favourite games as a kid.

I am not sure these tyres are ideal as all weather tyres either. I wouldn't want to drive these through heavy rains where one counters not only pot holes but deep puddles and flooding.

Also in the winter, snow would get jammed into the spokes reducing the efficiency.

I'd rather see tyres like the ones they use in Formula 1, tubeless tyres with sidewalls that act as the suspension and nice grippy contact patch.
posted by riffola at 4:14 PM on November 8, 2005

man, I just bought a new set of tires. These are much cooler.
*kicks self in ass*
posted by Smedleyman at 4:14 PM on November 8, 2005

What did the lunar rovers use for tires?

A similar design, but made of metal.

Hooking up an air compressor to fix a flat on the Lunar surface would be problematic, to say the least.
posted by Civil_Disobedient at 4:14 PM on November 8, 2005

the fact that they are filled with air creates some obvious problems.

it's been my experience that the obvious problems start when the tire isn't filled with air
posted by pyramid termite at 9:12 PM on November 8, 2005

Pretty cool.

But "tweel" is a lame name for these.
The should come up with something better such as "Super See-Thru Magic Airless (TM)" or something like that.
posted by sour cream at 4:45 AM on November 9, 2005

bartleby writes "Pneumatic tires on the moon rover? With no atmosphere? Nuh-uh. "

Why is no atmosphere a problem for a tire? The Astronauts brought lots of air with them and atmospheric pressure is only 14.7psi. I've routinely worked with truck tires inflated to 65psi and you want nice low pressures for a loose surface tire. An offroad 4X4 tire can be run as with less than 10 psi.

I'd bet NASA's non pnematic tire was more about reliability than lack of performance.
posted by Mitheral at 7:05 AM on November 9, 2005