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.

Re:You don't have to check your tire pressure

[Cyno01]

That'd be great for grocery shopping and taking the kids to soccer practice.

Non-pneumatic, made of elastic...

[Spoing]

1. They are non-pneumatic and made of elastic.

Modern technology, my foot! You can't fool me, it's super-elastic bubble plastic, right?

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?

[hitzroth]

There are a few problems with what you're saying.

First, rolling resistance has to do with how much energy is scrubbed away by the tire making contact with the ground (flexing and sticking and whatnot). What you're talking about with wheel weight is "rotational inertia," which is only relevant during acceleration (it takes no more energy to maintain a steady rotation of a heavy wheel than it does a lighter wheel if they have the same aerodynamics -- feel free to do the math yourself). Plus, while superlight wheels may feel really good at first, and while heavier wheels may start out feeling pretty sluggish, you'll get used to both after a ride or two.

Second, aerodynamics sucks dramatically more from the performance of a bicycle than any other factor. Don't believe me? Just remember how pleasant it is riding into a headwind.

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...

[fmaxwell]

Huh? I've never towed anything with my car

Wuss. ;-)

and as for "heavier loads" I guess that means 4 people in the car instead of just me.

Or a vacation where the car has luggage in it. Or where you are carring a heavy item in the trunk.

I inflate my tires to the recommended pressure for my car and everything seems fine.

Most cars have two different recommended sets of pressures based on the load in the car. If you're taking the family to the beach in a fully loaded minivan, the proper, and safe, tire pressure is not the same as if mom and one kid are riding around town.

As for compensating for different vehicle weights, That could be solved by adjusting the solid tire for weight.

So now you have a 185/70R15 in six different vehicle weight classes, and each person has no way to adjust the pressure when he should.

How many people want to trade tires between vehicles (or even have two vehicles with the same tire size)?

That wasn't the point. The point was that you and I could each have vehicles that required 205/70R14 tires and your vehicle may weigh substantially more or less than mine. we could both buy the same tires and adjust tire pressure accordingly.

I've never done this, though I live in a climate where snow is common in the winter. I've never heard anyone even recommend doing this, so I don't think it's very commonplace.

See this link for information on it. It is very worthwhile in soft snow, sand, or mud. When I volunteer to drive for the hospital in snow emergencies, I always drop the tire pressure on my Jeep down to about 10-15psi. It's why Humvees have a CTIS, or Central Tire Inflation System. That way, they can adjust pressure for the terrain, lowering it for snow, mud, sand, etc.

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.

No, they are points for everyone. The vast majority of people aren't computer enthusiasts and want nothing to do with performing security updates or installing anti-virus software. Being in the majority doesn't mean that someone is right.

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.

Well, no

[El]

Wouldn't rotational mass be a bigger problem for a car tire at 100mph than for a bicycle tire at 10mph? I'm not talking about replacing racing bike tires here, I'm talking about wide tires. Plus, I imagine they are using a foamed product that isn't much denser than compressed air.

By the way, I beleive the problem with wheel weight relates to turning and accelerating/decelerating, since each wheel is essentially a large gyroscope. It really shouldn't effect your steady velocity straight-ahead performance any more than, say, carrying a tire pump and flat repair kit!

Re:Are these guys for real?

[stoborrobots]

BTW, that quote was from TFA...

Anyway, some poking around on a search engine led me to this search
http://www.alltheweb.com/search?q=Michelin+Red+Gui de+restaurants
and specifically to the Michelin Red Guide to Restaurants...

It seems that it's not crazy Americans this time, but crazy Europeans... My bad...

michelin already has foam tire inserts for offroad

[Polo]

Michelin already makes foam off-road tire inserts for off-road motorcycles. I think the problem is heat build-up. They don't last that long and they aren't for on-road use.

Here is more info on the off-road tire inserts:
http://motous.webmichelin.com/tires/mousse.htm

Was I the only one who thought the fuel-cell comment was a gratuitous use enviro-buzzwords?

• This tire would react better to road conditions and to turning corners, and would be able to operate via a cleaner electric fuel-cell engine, said Miraton.

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.

Re:Are these guys for real?

[Matho]

In fact, the Michelin guide (where the top french restaurants are rated with stars) was created in the beginning of the 20th century to promote travel via road...and so to use Michelin tires on the early cars.

It was a pure marketing stuff : So you like to dinner in nice restaurants? Check out our guide, check out our road maps, go via michelin (and don't forget to buy our tires).

Today, in France, each yearly release of the Michelin Guide is awaited in fear and anguish by every top restaurant, as the lost or the gain of a star in the rating really impact the yearly number of dinner seats...

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.