Automotive Tires Without Air

pcman writes "It appears that in 10 years or so Michelin will have an airless tire. They are presenting them at the Paris Auto Show this week. They hope to adapt them for motorcycles, cars and heavier vehicles. They are non-pneumatic and made of elastic. You can read the whole story here. I am very interested and look forward to the day when I don't have to check tire air pressure. It is the 21st century after all."

Comments

You don't have to check your tire pressure

[exp(pi*sqrt(163))]

Some cars check it for you.

Why stop at motor vehicles?

[El]

What we really need these for is bicycles... and I'll bet there is a bigger market in India and China for bicycle tires than for automobile tires.

Re:Why stop at motor vehicles?

[real_smiff]

air has several advantages, one is comfort, but also it has a very low density, this means in bike speak low rolling resistance - weight around the edge of the wheel is probably the single most important factor in performance of a human powered bike... although it may have a market in chinese road cycles i wouldn't want to swap my mtb inner tubes for solid rubber, or even some "light" web that would add plenty of weight. the same physics would hold true for cars and anything else but i don't know how significant extra weight is if you have an engine. i haven't rtfa'd.

Re:Why stop at motor vehicles?

[Somegeek]

Airless bicycle tires have been commonly available for at least a decade. They are heavy and slow and there are many other ways of preventing flats on bikes now.

First google hit:

http://www.airfreetires.com/

Re:Why stop at motor vehicles?

[hughbar]

I use these in London (glass everywhere) and south west France (iron-like thorns everywhere). They give quite a hard ride but (for me) it's better than constant puncture repair. The first bicycle tires were solid, so this is an elightened step backward using new materials.

Prior art

[0x20]

Airless tires have been around since the 1920s, at least... here's proof.

Re:Prior art

[idiotfromia]

Uh, I believe oxen driven wagons were able to cross the untamed frontiers of the United States with airless tires. Before that, horses pulled wooden carts with solid wood wheels.

The point is that the new tires will be similar in design to the current and have the same stability and flexibility.

Wouldn't want adjustability or anything...

[fmaxwell]

I am very interested and look forward to the day when I don't have to check tire air pressure. It is the 21st century after all.

God knows that people in the 21st century wouldn't want to add air to compensate for heavier loads or towing. People in the 21st century wouldn't want to adjust tire pressure to acount for differences in weight between two vehicles that use the same size tires. Modern people in the 21st century won't want to reduce air pressure for traction in the snow. Oh, and we'll all have personal helicopters. I saw it in Popular Science.

Re:Wouldn't want adjustability or anything...

[theLOUDroom]

The points you bring up are for the car enthusiast. The vast majority of people aren't car enthusiasts and want nothing to do with adjusting tire pressure for different conditions.

It's a same to here you say this.
The post wasn't talking about equalizing your tire pressures for neutral cornering, or any orther type of esoteric car enthusiast type of practice.
Those were basic concepts that everyone who drives a car should know.

There's more to driving a car than pushing pedal and turning the wheel, when you're driving a car you are operating a very dangerous, very expensive machine, you SHOULD have some basic concept of how it works.
Whould you use a chainsaw with no more background knowledge than "set it on the wood and pull the trigger"?


Sadly this doesn't seem to be a part of any driver's test that I know about. Here's an example:

THINK FAST:
You gas pedal is stuck to the floor, should you:
A) reach down with your hand and try to pull it up
B) use the brakes to maintain your speed
C) shift your transmission into neutral
D) turn your ignition switch to the "accessory" position
E) Shut off your car by removing the key from the ignition

How many people out there know the correct answer to this question? Do you?
Don't you think this is a basic, necessary, safety-related thing to know?

I was lucky to have good instincts and pick to correct answer when it happened to me, but I would have much rather been taught the answer as part of my written test.

Note:
The answer is D, choose any of the other choices and you can fuck yourself in a hurry.
A) takes your eyes off the road
B) will burn up your brakes, then you have a car with a stuck gas pedal AND no brakes C) will toast your engine by overrevving it E) will kill your engine but will also engage your car's steering wheel lock
(some cars have features which minimize some of these problems)

And finally,
I'll admit it, I consider myself a car enthusiast.
You might claim that makes be biased, but I honestly think the current blatant ignorance of proper automobile operation is a serious safety issue.
Try this go to ANY brake repair shop and ask them how often the get cars in for brake service where the brake pads have been worn down to the point where there is bare metal on metal contact.
You'll find that a lot of drivers out there are blissfully ignorant of the "squealers" on their brake pads, whose entire purpose it to warn the driver before the vehicle becomes unsafe to drive. They just turn up the radio.

I don't expect every driver to know how to change his spark plugs, but every driver SHOULD know all the basic, safety-critical information about their car. It's like operating a gun without knowing how to use the safety, it's just dangerously stupid.

Inventing

[fulldecent]

So basically... they're reinventing the wheel.

Off-road vehicles

[ColaMan]

A lot of off-road equipment already have foam-filled or "airless" tyres.

The difficulty is that you can't adjust the foam compound inside the tyre - once you've filled that tyre and the foam is set that's it. If it's too hard, well, too bad.

The underground mine that I work at trialled some tyres for their light vehicles (toyota utes and such), as we regularly tear up tyres on rocks and sharp objects.

The main problems we found were :

Cost - they were AUD600 or so *each*. But they don't go flat, of course :-)

Ride quality- you could tell the vehicles with the foam-filled tyres straight away - they were ABSOLUTELY ROCK SOLID.

Weight - Think about the average volume of a tyre. The tyres on our vehicles were about 60kg each. That's a fair bit more unsprung weight rattling around and loading up your suspension components. The vehicles we trialled them on became noticeably "rattlier" in the suspension over the course of a month. "rattlier" to the point of people saying "what the hell is that noise? Oh , it's just the toyota going by."

They also trialled them on our heavy equipment, but again , they were too hard on the suspension components, even after trying half a dozen different fill compounds. A worrying number of cracks appeared in the bodies of our trial haul trucks as well... so they decided to can that idea.

But hey, you know the relentless march of technology, maybe they'll sort it out. Still think they'd be too heavy for my liking - one of the goals of getting good suspension is to reduce unsprung weight (mag wheels, drilled rotors, etc) and adding another 20kg of extra rubber compound on each wheel aint gonna help.

Probably will be outlawed in the US

[spikestabber]

Police spike strips will become useless. Anything innovating the DOJ wont like gets outlawed.

Re:Propane

[Anonymous Coward]

I agree it's stupid, but here is one way people do it.

Would you inflate your tires with propane? Although most people would answer, "are you crazy, of course not", these same people are routinely inflating their tires with so-called "tire sealants" that are nothing but propane and perhaps a little isobutane.

Effects on Fuel Efficiency

[kallistiblue]

I wonder how these new tires would effect the miles per gallon.
Hybrid cars do a a good job of increasing the the MPG. I would hate to see these tire wipe out the gains in efficiency.