
Airless Tires Roll Towards Consumer Vehicles - simonebrunozzi
http://spectrum.ieee.org/cars-that-think/transportation/advanced-cars/airless-tires-roll-towards-consumer-vehicles
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gooseyard
Michelin has been marketing their "Tweel"
([http://www.michelintweel.com/](http://www.michelintweel.com/)) product for
industrial applications for a while, and I've read a couple of articles about
their trials of the Tweel on passenger vehicles. I suppose that the challenges
of higher speed applications have prevented that product from appearing.

Personally, I want some Mattracks :)
([https://www.mattracks.com/](https://www.mattracks.com/))

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seanp2k2
I've seen them on construction equipment, which admittedly moves very slowly.

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achamayou
They get rather wobbly and noisy as you reach higher speeds.

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userbinator
If they can get the requisite approvals planes seem to be an ideal application
of these, as burst tyres upon landing or takeoff are actually rather frequent
and the shrapnel can cause extra damage... sometimes leading to catastrophic
results:

[https://en.wikipedia.org/wiki/Air_France_Flight_4590](https://en.wikipedia.org/wiki/Air_France_Flight_4590)

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ChuckMcM
Something I always wonder about is the mass. Airless tires have a lot more
mass around their edges than pneumatic ones do and so at higher RPMs would
seem to put more stress on both the axle and the wheel, especially when
turning. That seems like a really hard problem which gas solved really well.

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ak217
Yes, also known as unsprung weight. This is one of the reasons airless tires
have a long way to go before they can hope to replace regular tires.

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upofadown
The pneumatic tire is an awesome invention. They have the ability to cancel
out imperfections in the road surface over a wide range of frequencies and
amplitudes. Bicycles have traditionally used no other type of suspension.

To make a non-pneumatic tire you have to invent something equally as awesome.
Normally you end up with something that produces a very rough ride.

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barrkel
A rough ride is the least of your problems. In a powered vehicle, the primary
purpose of suspension is to keep you in contact with the road. If you're not
in contact with the road, you're not in control; braking, steering and
acceleration don't do anything if they can't react against the surface.

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rtkwe
> The series of “rigorous tests” that the company is putting its tires through
> are meant to prove their durability, hardness (efficiency), stability,
> ability to take high-speed turns (slalom), and ability to _maintain their
> integrity at high speeds (up to 130 kilometers per hour)._

That's only 80 MPH. I'm interested in the no flats and potential fuel savings
but I'd want to be able to travel at freeway speeds on long trips with them
too without having to change out tires.

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commandar
What exactly do you consider freeway speeds?

Even in the metro ATL area which is notorious for thinking the speed limit is
a suggestion, the vast majority of traffic is moving under 85 MPH.

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userbinator
[https://en.wikipedia.org/wiki/Tire_code#Speed_rating](https://en.wikipedia.org/wiki/Tire_code#Speed_rating)

 _In many countries, the law requires that tires must be specified, and
fitted, to exceed the maximum speed of the vehicle they are mounted on, with
regards to their speed rating code (except for "temporary-use" spare tires)._

I see it as a safety factor - the speed ratings of most common tires (S or T,
180 or 190 km/h) are far beyond what most people will ever drive at. If this
one is only rated to 130km/h, that decreases the safety factor.

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kirk21
Great article about a previous innovation of Michelin that failed: In the
1990s Michelin developed a revolutionary new kind of tire with sensors and an
internal hard wheel that could run almost perfectly for 125 miles after a
puncture. They forgot to involve the ecosystem.

[http://www.forbes.com/sites/frederickallen/2012/03/05/why-
gr...](http://www.forbes.com/sites/frederickallen/2012/03/05/why-great-
innovations-fail-its-their-ecosystem/)

(edit: not being negative on this new product, just providing some context)

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usaphp
I am pretty happy with my run flat tires on my bmw, even after a blowout they
remain normal and handling is near normal as well, plus you can drive like
100miles and 50mph to a nearest tire shop. The only downside is they are more
expensive and sometimes if you cought nail close to a tire sidewall it means
you I'll have to replace a tire since it's not fixable

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seanp2k2
And they ride more harshly, are less compliant, are heavier (look at how much
some spend on light-weight rims; tires are even further from the center of the
wheel), more expensive, can get bent / dented, and rely on finicky tire
pressure monitoring systems.

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usaphp
They might be heavier but they allow you to get rid of a spare wheel, so
overall the car is lighter.

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rpcope1
Beyond the issue with unsprung weight, that seems like a truly awful trade-
off. A run-flat still needs to be serviced if punctured and is still
vulnerable to sidewall damage and potential blow-outs. If you carry a full
size spare (I sure do) in the event of most tire failures, you still have the
ability to get much further down the road with less drama.

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usaphp
None of the new sedan vehicles carry a full sized tire, they all carry a
temporary one, which can only be driven 50 miles at low speed. So still worse
than broken run flat

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rpcope1
They don't come with one stock, sure, but there's nothing to stop you from
going and buying the correct sized steel (or cheapo alloy) wheel and a decent
tire that's the same size as the ones on the car and carrying it with you (and
throwing the junky temporary spare out). Yeah it requires you to work a touch
extra on the setup, but it is worth it. The extra full size spare will cost
about the same as going with run flats vs non-run flats each time you swap out
tires.

If you're interested, it's pretty easy to get the correct sized wheel from
somewhere like RockAuto or Discount Tire Direct.

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dbbolton
The demo video touts them as "eco-friendly", and I'm assuming they mean
relative to traditional pneumatic tires, so how are they actually better in
that regard?

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simonebrunozzi
There might be multiple factors: how much you pollute to produce them (much
less, considering that there is almost no metal involved, unlike with
traditional tires which have alloy wheels); how much they get consumed by
usage, compared to traditional tires; how much they pollute to dispose of
them.

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cordite
That's a cool video, but I've seen enough CG-salesy examples from vaporware
projects--with similar animation and admittedly high-quality concept videos--
to feel skeptical.

Given how well similar tires seem to work for the military, and potentially
low-cost replacement road-contact parts, I'd support it. However, my worry
is... what if the manufacturer and or distributor went out of business? Will I
have to replace all my tires just because one got a little shredded up from
some debris? (I assume mixing tires which might have different sizes /
radiuses is a bad idea)

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brownbat
Watch for stats on rolling resistance, tire weight, impact on suspension /
size, and cost before getting excited.

Punctures occasionally cause blowouts, and those are awful, but still subject
to tradeoffs. If airless tires tank the efficiency of your vehicle you'll
think to yourself, "Well, _I 've_ never had a catastrophic blowout... and
changing a tire is a pain, but isn't _that_ bad."

We've used airless for decades, just not in cars. We aren't just waiting for a
simpler manufacturing process, there are other constraints at play.

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dylanrw
Inb4 congress tries to pass a law prohibiting them because they can be used by
villains to defeat LEO's spike strips.

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detaro
Wouldn't run-flat tires then already be banned?

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MrFoof
No. The purpose of run-flat tires are to get you to pull off the road safely,
or travel a small number of miles at low speeds to somewhere where you could
have a replacement mounted and installed immediately. They are not intended to
run without air for extended periods of time, or at highway speeds. They are
also not to be driven on AT ALL in the event of a sidewall puncture.

The casing would still fail catastrophically at high speeds (i.e. pursuit
scenario), and having a tire down over 30psi on one wheel would very seriously
affect handling at any significant speed (40mph or more).

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analog31
I'd be interested in better efficiency and lower operating cost. As for
safety, I'd have to see the stats on how often modern tires blow out. And a
demonstration that lower operating costs on the tires doesn't translate into
higher costs for maintaining other components such as bearings and suspension.

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coldcode
I wonder if you can 3d print a rubber tire shape someday. You might be able to
engineer a shape that might be hard to make otherwise and solve some of the
issues not having air.

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burger_moon
I'd be interested to know how well layers of 3d printing holds up to that much
rotational mass, lateral forces, and vibration at freeway speeds. I have my
doubts at this point of its feasibility.

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ajcarpy2005
A 3D printer could be used to create the mold for the rubber perhaps.

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TheLoneWolfling
You can easily do a lost-wax process with a 3D printer.

(Although getting the precision may be difficult.)

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Sodel
Some folks have already moved on to a lost PLA casting process. I've seen some
pretty decent results.

[http://3dtopo.com/lostPLA/](http://3dtopo.com/lostPLA/)

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sown
I remember seeing this concept appear over the years. I suppose this means
they solved heat dissipation and vibration issues?

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hakcermani
Would love to see a bicycle tire with this. Way too many glass pieces on bike
lanes :-(

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cpkscpks
Puncture proof bike tires work extremely well. I have Continental Top Contact
tires. Except for overinflation (my fault), never had a flat over thousands of
miles. They feel nice to ride on too. Before that, I had Panaracer ribmo
tires. No flats, ever. However, the ride was a little bit stiff.

Both were a little heavy, but worth the extra weight.

If you're getting flats, that's a much better solution.

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comrade1
These have been around a long tme, especially for armored cars (I saw them on
an Audi W12). I was told the ride is rougher than pneumatic tires but have the
advantage that they can't be punctured by gunfire, or whatever.

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rue
The point of these is, presumably, to be as comfortable as conventional tires.

