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Technology Science

Automotive Tires Without Air 73

Posted by timothy from the please-hurry-up-with-these dept.
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."
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Automotive Tires Without Air More

Automotive Tires Without Air

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  • You don't have to check your tire pressure (Score:4, Interesting)

    by exp(pi*sqrt(163)) ( 613870 ) on Tuesday September 21, 2004 @06:55PM (#10314491) Journal
    Some cars [maximog.com] check it for you.

  • Non-pneumatic, made of elastic... (Score:3, Funny)

    by Spoing ( 152917 ) on Tuesday September 21, 2004 @06:58PM (#10314511) Homepage
    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? (Score:5, Insightful)

    by El ( 94934 ) on Tuesday September 21, 2004 @07:04PM (#10314555)
    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? (Score:4, Interesting)

      by real_smiff ( 611054 ) on Tuesday September 21, 2004 @07:29PM (#10314741)
      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.

      • Well, no (Score:3, Interesting)

        by El ( 94934 )
        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

        • It may not affect your velocity... but have you ever ridden in a vehicle with an unbalanced tire? Depending how badly its off, the shaking can begin at 30+mph, and be unbearable at 60mph.
        • Legs by their very nature are a pulsing power stroke, thus continously accelerating, even if by a small amount, it happens every single stroke. Rotating mass is the very devil on a human powered vehicle. I have seen estimates that weight on the rims is worth ten times as much weight on the frame.
          • So why do bicycles generally have large wheels at all? For mountainbikes it makes sense - you need large diameters to handle very uneven terrain - but for road bikes, small wheels really should be preferable.

            Gearing is not an answer; just change the gear ratio earlier in the drive train. Stability isn't an answer either. I currently use a high-end foldable bike with 14" wheels, and it's just as steady as my previous, full-size wheeled, bike.

      • 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 superlig
    • and I'll bet there is a bigger market in India and China for bicycle tires than for automobile tires.

      Good luck trying to sell bike tires in India for $700 a set...
      • Good luck trying to sell bike tires in India for $700 a set...

        Well the counterfeits will be much less expensive and they won't be restricted to India, China, etc. You will see them in the U.S. on ebay. Amazing deal, $700 tires for only $250.
    • 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/ [airfreetires.com]

    • I use these [greentyre.co.uk] 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 (Score:4, Interesting)

    by 0x20 ( 546659 ) on Tuesday September 21, 2004 @07:04PM (#10314561) Homepage
    Airless tires have been around since the 1920s, at least... here's proof. [livinghistoryfarm.org]

    • Re:Prior art (Score:3, Insightful)

      by idiotfromia ( 657688 )

      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.

    • I believe they used a hollow, rubber toroid that was inserted into the tire before it was seated to the rim, with a small filling tube prodruding through the rim to allow it to be filled with air. This was useful because it was extremely difficult to make a tire that was both strong enough to support the vehicle and had a good enough seal on the rim to hold the air. (I think it's called an "inner tube")

      I think a better example would be the "Run Flat" [tirerack.com] tire which appeared a few years ago.
      =Smidge=
      • IT WAS A JOKE! maybe not a good joke, but jeez. the car in the picture i linked, if you will note, has a FLAT. flat tire. airless tire. get it?

        so now i've been scolded for assumptively not knowing that wooden wheels existed AND had the concept of inner tubes (which i already understood, as i'm not from MARS, for god's sake) explained to me in full.

        next time i try to make a joke on slashdot, i'll remember to just explain the whole thing in completely literal terms.

  • Comment removed (Score:5, Interesting)

    by account_deleted ( 4530225 ) on Tuesday September 21, 2004 @07:14PM (#10314622)
    Comment removed based on user account deletion
    • Given that the average city driver never does any of these things, yes, you're absolutely right.

    • 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.
      Huh? I've never towed anything with my car, and as for "heavier loads" I guess that means 4 people in the car instead of just me. I inflate my tires to the recommended pressure for my car and everything seems fine.

      As for compensating for differ

      • Re: (Score:3, Insightful)

        by account_deleted ( 4530225 )
        Comment removed based on user account deletion
        • 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.

          Those are more analogous to changing oil. Adjusting tire pressure for better traction in snow is more like defragging your hard drive. Not necessary, and only something people who are into computers would really do. It doesn't say anything about varying the tire pressur
          • Comment removed based on user account deletion

            • Tire pressure recommendations are not just for comfort, they are for safety. For example, a car with underinflated tires is less able to quickly change lanes in an emergency.
              We're not talking about pressure recommendations, we're talking about varying your tire pressure. Obviously tires not inflated to the recommended pressure are a problem.

              I still stand by my conclusion that the vast majority of people have no need to change tire inflation. Unless you're towing a trailer, or carrying around 500 pound

      • Re:Wouldn't want adjustability or anything... (Score:4, Informative)

        by theLOUDroom ( 556455 ) on Tuesday September 21, 2004 @09:55PM (#10315608)
        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.
        • It is best to
          1. Step on the brakes.
          2. Shift into neutral
          THEN
          3. Turn the key to accesory.

          The problem is you are very likely to turn the key too far, locking the steering wheel in many cars. Also, power steering and brakes will only work for a few seconds after the engine is off, so you should point the car in a safe direction and get on the brakes before you shut down the engine.

          • The brake assistance doesn't stop a few seconds after the engine's turned off - it stops after you have used the reserve pressure by depressing the pedal.

            Try pressing the brake pedal on a car which has been standing still for a while. You'll be able to do it once, maybe twice, before you lose the assistance and the pedal becomes much harder. You can still brake, but it takes a lot more effort.

            If you're travelling at any kind of speed, losing power assistance won't be a problem as long as you're expect
        • >Whould you use a chainsaw with no more background knowledge than "set it on the wood and pull the trigger"?

          Actually, you should have the chainsaw at full chain speed prior to engaging the wood... works *much* better that way :-)

          THe rest of your post is right, though... aside from us VW owners who don't have an accessory position. If you turn the car off, then back to the on position (yes, you should take the car out of gear once the engine is off, but my foot always hits the clutch when I turn the ke

        • 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.

          But in practice, people don't know much more than that and don't care. Heck, most people are only even vaguely aware of where their tires are at any given time -- you wouldn't believe the sheer number of times I see people who can't turn a corner on a two lane road without sliding into other lane.

          O

        • The answer is D, choose any of the other choices and you can fuck yourself in a hurry.

          Happened to my girlfriend on the freeway and she chose B. She managed to exit and pull into a parking lot across the street from a gas station (she didn't want to try for the left turn). It helped that she had been racing at (bicycle) track nationals the week before, where doing insane things at high speed and very close to other people is normal (and track bikes don't have brakes...). The repair was about $27, ($2
    • I am a person in the 21st century, and I surely don't want to have to do any of those things.

      But with a solid tire, would you actually see any benefit from adding air to compensate for loads, or for weight of different vehicles?

  • Inventing (Score:5, Funny)

    by fulldecent ( 598482 ) * on Tuesday September 21, 2004 @07:34PM (#10314775) Homepage
    So basically... they're reinventing the wheel.

  • Off-road vehicles (Score:5, Informative)

    by ColaMan ( 37550 ) on Tuesday September 21, 2004 @07:41PM (#10314824) Journal
    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 (Score:4, Insightful)

    by spikestabber ( 644578 ) <spike@@@spykes...net> on Tuesday September 21, 2004 @07:53PM (#10314894) Homepage
    Police spike strips will become useless. Anything innovating the DOJ wont like gets outlawed.
    • It is a lack of clear thinking like you show above that limits your JackBootedThug potential. You are looking for the tired to be outlawed, which is wrong. The goverment will just mandate that every new vehicled that can have said tires installed on them will have a remote, LEO only, kill switch. They will also mandate that any older vehicle have such a device installed if they get said tires.

      To improve you JBT potential please check how the GOP/DEMS treat protesters. Look for "free speach zones" in yo
    • Wrong. Run flat tires aren't outlawed and they render the spike strips *useless*. Many cars get the run flats stock, for instance the mini cooper S.
  • We have more than one tractor with propane in its tires. It keeps one from smoking while working, that's for sure. :-)
    • what's the benefit of filling a tire with propane?

      • Re:Propane (Score:1, Funny)

        by Anonymous Coward
        so you can post on slashdot and say you have tires filled with propane... duh? I thought that was obvious!

      • Re:Propane (Score:4, Informative)

        by Anonymous Coward on Tuesday September 21, 2004 @10:17PM (#10315757)
        I agree it's stupid, but here [tamu.edu] 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.
    • Lots of heavy trucks over here use dry nitrogen, which prolongs the life of the tyre by eliminating one source of degradation.
  • well that was a pretty vague article, and what's with this:

    and would be able to operate via a cleaner electric fuel-cell engine

    because I'm sure normal tires don't work with an electric fuel-cell engine...
  • Michelin, famed for the star ratings it gives upmarket restaurants, will also present ...
    I'm not from the US, but does a tyre manufacturer really go out and rate restaurants?

    Really?

  • michelin already has foam tire inserts for offroad (Score:3, Interesting)

    by Polo ( 30659 ) * on Tuesday September 21, 2004 @10:06PM (#10315683) Homepage
    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 [webmichelin.com]

    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.

  • hola [porsche.com.ar]

    After all, it is the 21st century

  • Effects on Fuel Efficiency (Score:3, Informative)

    by kallistiblue ( 411048 ) on Wednesday September 22, 2004 @01:22PM (#10320927) Homepage
    I wonder how these new tires would effect the miles per gallon.
    Hybrid cars [hybrid-car-reviews.com] do a a good job of increasing the the MPG. I would hate to see these tire wipe out the gains in efficiency.

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