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NASA Businesses Technology

Startup Debuts Airless Bicycle Tire Based On NASA Rover Tech (techcrunch.com) 121

Posted by BeauHD from the game-changer dept.
New submitter byennie writes: A new airless bicycle tire called "METL" was introduced today by The SMART Tire Company. The tire is made from shape memory alloys (SMAs) and was originally designed for Mars rover missions (it's headed to Mars in 2026 as part of the Fetch rover). The structural tire claims to be flat-free and high performance, leaning on the unique properties of SMAs developed at NASA for future heavy vehicles in space. According to the company, "the shape memory alloy tire is made from advanced, lightweight materials known as NiTinol+, creating a tire that is elastic like rubber yet strong like titanium, exhibiting perfect shape memory without ever going flat."
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Startup Debuts Airless Bicycle Tire Based On NASA Rover Tech More

Startup Debuts Airless Bicycle Tire Based On NASA Rover Tech

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  • Flat tyres are a solved problem, the rare cases I've had over the years on 6 bicycles that I take care of would not warrant a more expensive solution. Which likely is heavier too, no matter how lightweight the materials are. For a rover on Mars? Sure, great solution. For a bike that's 2 minutes away from a repairman? Not so much.
    • In my house the repair man happens to be me - it is actually easier to fix my kids bikes than transporting it to a bike shop and pay for it. But all in all I have to spend like half an hour. The real problem is getting flat away from home. When I ride my racing bike I always have two spare tubes in my pocket, but it is really not fun to be changing tubes in cold rainy weather on the side of the road. The new thing seems to be "tubeless" (like on cars). It is supposed to be self healing by having some glu

      • Re: (Score:1)

        by Anonymous Coward

        Tubeless works great on mountain bikes, I have multiple rims with tires on which all have +20 holes each right now. I can see that because of the wet spots on them. Idk about race bikes.

      • The new thing seems to be "tubeless" (like on cars). It is supposed to be self healing by having some glue like stuff sprayed into the tire, but if you get a larger rift you probably have to get a whole new tire - good luck when standing 50 km from home in the middle of nowhere.

        You can get tubed ones pre-loaded with that junk and also cannisters of it to spray inside. I used to use them on my mountain bike when I had places to mountain bike. The landscape had little sharp rocks and sharp thorny seedpods, a

        • No reason you can't run sealant inside of tubes. Makes maintenance less messy, but adds unnecessary weight.

          • No reason you can't run sealant inside of tubes. Makes maintenance less messy, but adds unnecessary weight.

            Yeah that's what I ran. I had lightweight high performance tyres, and sealant filled tubes. The weight penalty was less than more robust tyres.

            TBH is was kind of wankery on my part. It's not like I was a pro mountain biker or anything, but I was in my first job, had cool biking nearby and wanted to blow some hard earned cash on a sweet bike.

      • That tubeless sealant doesn't work that well with high tyre pressures and the installation is a bitch unless you have UST rims and tyres.

      • Yeah - I've actually been eyeballing those puncture-proof foam tube-alternatives that you can drive a nail through without problems just to eliminate the nuisance. They do add weight - but I've been considering going electric anyway, and have got to deal with big goats-head thorns that present a serious challenge even to decent puncture-protecting tire liners. (which aren't exactly weightless themselves)

        Someone above mentioned touring tires with built-in metal liners - that sounds like something worth inve

      • I carry a plug kit, some extra sealant, and a couple CO2 inflators for those occasional holes that don't seal well with sealant.

      • ...but it is really not fun to be changing tubes in cold rainy weather...

        Ok, I"m sitting here, reading this and trying to figure out WTF you are doing out riding a bike in cold rainy weather?

        You don't have a TV/radio or other way of seeing what the weather forecast is going to be?

        Just curious.

        • Bike commuters, unexpected showers that weren't in the forecast, or just riding on one of the many days where there is a "chance" or rain.

    • One night, a couple weeks ago, I had a sudden flat and ended up having to change my car tire out in the pouring rain. That was pretty miserable.

      I’m guessing this new tire falls into the “if you have to ask, you can’t afford it” price category though.

      • One night, a couple weeks ago, I had a sudden flat and ended up having to change my car tire out in the pouring rain. That was pretty miserable.

        I’m guessing this new tire falls into the “if you have to ask, you can’t afford it” price category though.

        I have run-flats on my car. They ride like shit, but they sure are nice in situations like yours.

    • For your use case, perhaps. Flat tires are certainly not a solved problem across mountain bikes, gravel bikes, eBikes, micromobility fleets, and so on. Nor for all casual riders who are less good at regular maintenance, ride in bad weather, or are prone to punctures. Blowouts still happen and are serious when they do. Many bikers try airless solutions for good reasons, they typically just don't perform well enough.

      Regarding lightweight, it also depends on the application. Versus the lightest possible road b

      • Obviously air wins

        Greg LeMond would differ with you. He used to use helium. With HP, that's 15 grams. Three spokes!

        • People also use helium or hydrogen in tires because they are dehumidified as they are bottled, which reduces changes in pressure as the tire heats up. Same reason shocks are charged with nitrogen instead of plain air.

          https://www.tyreplex.com/news/... [tyreplex.com]

    • Re: (Score:3, Informative)

      by ShanghaiBill ( 739463 )

      For a bike that's 2 minutes away from a repairman? Not so much.

      Some people ride their bikes more than two minutes from home.

      Dealing with a pump and patch kit on a mountain road as daylight is fading away is not fun.

      I'd love a tire that never goes flat.

      • You are right, but I doubt that a tire that never goes flat would be very comfortable to ride on, Especially on a bumpy mountain road. Also, if you're into traill riding, having the tire conform to irregularities in the trail such as roots and rocks helps a lot with grip. I don't really thing this is meant as a solution for avid sport riders but most likely will be used in commuter bikes and rental bikes by people who don't know how to deal with changing a flat.

        However, a good commuter tire can already go

        • Re: (Score:2)

          by rtb61 ( 674572 )

          You know if you stop and really think about it, there is a whole lot of things you can do with light weight wheel construction, more imaginative use of wheel rims and tyres, all sorts of things can be done. Interesting thing to think about recumbent cycles are changing biking in interesting ways. You can even do stuff to get a better wheel chair up stairs, wheel and tyre design, still interesting things can happen there.

        • You are right, but I doubt that a tire that never goes flat would be very comfortable to ride on, Especially on a bumpy mountain road.

          In the case of the article, they indicate it is equivilent or better. The shape memory metal is made into small springs that look like a tire, so have the same deformation ability as a tire, but they return to the previous shape after deformation.

        • Also, if you're into traill riding, having the tire conform to irregularities in the trail such as roots and rocks helps a lot with grip.

          It happens that my town has the most dangerous mountain bike trail in the world. If this tire can take our White Line, it will work anywhere else.

    • You're a self obsessed Slashdot pundit/whiner. Did you even bother to read the article or did you just look at the picture of the bike tyre and see an opportunity to trash people who have accomplished something?

      An actual quote from the link that you do not seem able to understand:

      SMART’s technology has the potential not only to make flat tires or under inflation a thing of the past, but could reduce cost and waste long-term by supplementing the need for rubber tires, which need frequent replacement a

      • I don't buy super fancy bike tyres but a "sensible choice" costs something like half as much as a budget car tyre, which means "per weight" it's easily 10x or 20x the price. So expensive materials could be feasible here where in a car tyre they are simply out of reach.

        • This is not to deny that cost is one of the challenges with this technology, but is it really a given that say 500 linear feet of metal wire, even a premium metal, is going to price out car tires, especially in total cost of ownership, when produced at scale?

          • Considering how often you replace vehicle tires, I would see a double or triple cost well worth it considering how often I have gotten flats.

            My Tundra costs approximately $500 per tire, they last 30-60k miles. Not risking getting a flat, or even multiple flats when out camping would be well worth the cost. I just recently had to replace two (can't replace one due to the wear...) because a bubble formed in the sidewall, likely due to a pothole, this problem wouldn't even happen with this shape alloy, thoug

      • Sorry, you lost me at "reading the article". Please keep such dirty talk off of Slashdot, and hand in your card at the door.

    • Re: (Score:2)

      by nagora ( 177841 )

      I think the target market is outdoor bikes, not spinners. But thanks for posting.

    • The problem is only solved for the commoner/commuter. If they can match the performance of a racing tire than those 2 minutes can make all the difference in the world.

    • It's sure not a solved problem when a 30min bike ride on your lunch break turns into a 15min ride and a 90min walk due to a flat tire.

    • The technolocial answer nowadays is kevlar. Everyone who does serious miles on a bike has kevlar tyres. They're practically impossible to put a hole in.

      Unless you're using old-school track-bike tubular tyres it's the inner-tubes that puncture. So if your clinchers are strong enough - no flats.

      • I run Kevlar tires, but I still get a flat every 2-3k miles on my road bike (1-2 times a year). They help, but they won't stop a shard of glass if it gets in just right. Still need to run with flat fixing tools and a spare tube if I'm going out for more than a short ride.

    • Flat tyres are nothing like a solved problem. Even more, DURABLE tyres are not a solved problem. I go through at least two sets of tyres a year on a single one of my bikes. In bad years, it may be 4 sets across all my bikes. It depends on how much I'm riding, obviously, and what the purpose of the tyres is.

      There are basically 3 different types of bike tyres.

      * Clinchers—this is the tyre and inner-tube combo that most people know
      * Tubeless—a newer style that's popular in mountain biking. There is

      • . I ride somewhere between 5000 to 7500km a year, which is a fairly middling amount for even a serious amateur cyclist, and good tyres cost me something like $80CDN PER TYRE each time.

        I know a tyre that works for everything you've mentioned except for mud (it really sucks for mud) and usually lasted me for about 10000 km. It is also somewhat cheaper.
        Schwalbe Marathon Supreme in the 2" width. Yes, it is a slick and best on the road, but it is fat enough to go through light terrain safely and uses a very grip

    • > Flat tyres are a solved problem

      Not on a kids push chair they're not. We had a twin Mountain Buggy with inflatable tyres - when all was well, it was the most manoeuvrable, most low rolling friction thing you could find anywhere. However, after about a fortnight, I came home with a flat - because that most terrible of things had happened - I'd rolled over a thorn. Yep, you could look at that thing in the wrong way and it'd get a puncture.

      I changed the tube and put in some of those plastic liner things th

    • If you're a roadie that spends entire days out on the highway, you're not two minutes away from the repair man. I'm routinely forty to fifty miles from home during the summer months. Not wondering when I'm going to have to change an unexpected flat would be a godsend even if they were more expensive than my current tires.

      I wouldn't spend that much more on a daily commuter bike or a round town bike, but for a bike that logs at least hundreds, sometimes over a thousand miles a year? Hell yeah, I'll take an

    • Re: (Score:3)

      by hey! ( 33014 )

      I was going to say the same thing. The place that manufacturers skimp on the cheap to mid range bikes most people buy are wheels and tires, because good wheels and tires are surprisingly expensive and most buyers in the sub- $1000 market aren't aware how important they are. A quality tire's finer casing will eliminate most flats that occur with a cheaper tire.

      Even cheap bikes these days are amazingly good -- *except* for the tires. If you have a bike that flats a lot, you can ask your mechanic to put on

      • Re: (Score:2)

        by cusco ( 717999 )

        Mechanic? It absolutely astounds me to this day that people PAY someone else to work on their bike. I'm embarrassed when I get so lazy that I pay someone to change the oil on my truckette. My bike? Forget it.

        • Re: (Score:2)

          by hey! ( 33014 )

          Mounting and inflating a tubeless tire on a compatible rim can be challenging for a beginner. The fit is much tighter. Also seating the beads requires a compressor or a special high volume pump. Sure, I could probably mount a low volume tire without tire irons and with a regular floor pump, but I wouldn't send a newbie down that road -- I want them to have good experiences with their bike, not frustrating ones.

    • Which likely is heavier too, no matter how lightweight the materials are.

      Everything that goes into a space probe has to meet strict weight standards. Those metal tires will probably weigh less than rubber ones.

  • The article claim that these tires can provide comparable traction with pneumatic ones. But bike tires are never been about traction: road tire are slick, off-road tires, which require traction, have knobs.

    What matters, on the other hand, is rolling resistance (i.e. the amount of energy one tire dissipates during its deformation), shock adsorption (which is related to rolling resistance) and weight.

    A tire made of wire mesh is typically poor in three parameters

    • These tires comes with integrated rubber treads - the photos are for illustrative purposes.

      Regarding rolling resistance, you're exactly correct. Note that the tires are going to Mars partly because they run on solar power, and energy efficiency is at a huge premium. As a wire mesh.

      While not quite apples to apples, it's worth noting that shape memory alloys are used for shock absorption in construction projects.

      • Re: (Score:2)

        by dfghjk ( 711126 )

        But shock absorption involves energy dissipation, the enemy of rolling resistance.

        A bicycle tire with high rolling resistance is a non-starter, there are already plenty of puncture-proof solutions that roll poorly.

        "These tires comes with integrated rubber treads - the photos are for illustrative purposes."

        Don't see any evidence of that, nor is it a trivial matter. Unlike the OP's claim, traction IS important, but it cannot come at the expense of rolling resistance. Furthermore, if traction is provided by

    • Sorry, meant to address this better in the previous comment. ALL bike tires have traction requirements. They just differ by application. A road tire with less than the required traction is a death trap. Rolling resistance is a huge concern, but probably secondary to staying upright around corners.

    • But bike tires are never been about traction: road tire are slick, off-road tires, which require traction, have knobs.

      Well...

      The knobs provide good traction on soft ground, because they dig in. On a dry road you get worse traction with knobblies because you have a smaller contact area. On a wet road it depends on the surface, tire pressure and which configuration forces more water out of the way.

      • That's why they make combo tires with a smooth strip down the middle. You still.wear off the lugs if you ride much on pavement though.

        • That's why they make combo tires with a smooth strip down the middle. You still.wear off the lugs if you ride much on pavement though.

          Yep, and they make cornering a bit dicier since you lose grip when you lean over, just when you need it most.

          • I only ride on dirt any more so I don't run 'em anyhow.

            I need new rubber, last tires were Kenda Nevegal and they are fantastic but they also crack at the sidewalls and I ride infrequently enough that this becomes an actual problem. I don't buy Michelins for my vehicles any more for the same reason...

      • Re: (Score:2)

        by quenda ( 644621 )

        On a dry road you get worse traction with knobblies because you have a smaller contact area.

        Contact area is just weight/pressure. The disadvantage of knobblies on road is extra rolling resistance from the rubber flexing.

        • Contact area is just weight/pressure.

          Only if there's no stiffness. Counter example:

          Imagine the bike is somehow balancing on something that looks like a nail with a very large head, with the tyre on the head and the point touching the ground. In this case, the nail has a lot of stiffness, so the contact area can be tiny (just the nail point).

          Of course the contact area is between the tyre and the nail head. But now imagine the nail is embedded in a block of rubber and physically attached to the tyre. The cont

          • Re: (Score:2)

            by quenda ( 644621 )

            Contact area is just weight/pressure.

            Only if there's no stiffness.

            Stiff knobs concentrate the load, so a greater pressure on a smaller area. Still the same total force, and traction is force x static coefficient of friction.

            If we talk about contact area of the knobs, we run into the coastline problem [wikipedia.org]. Do the knobs have smaller knobs on them? What about the stones in the road surface? It isn't a billiard table.

            For your nail, the formula still applies. The only reason nails lose traction is they have less friction than rubber. Contact area is not important, unless large

  • Crossing a bit of mud must be an interesting experience with such a tire.

    Flat tire problem is almost completely solved by going tubeless with a bit of sealant liquid in the tire. This takes care of all small punctures and big ones are extremely rare.

    • Exactly my first concern :) Effectively we'd be riding a tire made of a sieve... AND even if one agrees to just ride it only on paved roads shit, literally, will happen :D

  • The manufacturers claim a perfect shape memory and yet the NASA rovers on Mars have had persistent problems with wheels cracking when going over rocks. On Mars, these wheels probably still the best solution because of the environment. On Earth, they may not be.

    If they last for as long a distance on Earth as they have on Mars, there are going to be some very disappointed people when their wheels break down and crack after a few miles.

    • The current Mars rover wheels are not made of shape memory alloys. Curiosity and Perseverance have large rigid wheels made of thin aluminium, in a configuration that worked well on the much smaller MER wheels but turns out to have problems in some terrain types when you scale it up.

      These SMA wheels are more similar to the Lunar Rover wheels than to any current Mars vehicle.

  • Price (Score:4, Funny)

    by AlexHilbertRyan ( 7255798 ) on Wednesday March 17, 2021 @06:49AM (#61167534)
    Must be cheap thats why the mention the price multiple times. This will put those tubes from china by cutting their prices.
  • Another option, already on the market - but kind of a niche, are the airless tires made entierly out of foam. There are also foam inserts for tubeless, which works great in situations when the sealant fails to seal before loosing pressure... Nexo, tannus, vittoria airliner are the words to look some of those options up

  • Because TechCrunch either deleted it or just doesn't like my computer, here's the Yahoo version: https://finance.yahoo.com/news... [yahoo.com]

  • From TFA
    "wow can't wait".

    Here:
    "everything new is bad!!11"

  • For the $10,000 bicycle buying crowd. (I notice that nowhere does the article even hint at the cost...) People like me, who buy a bike for under a grand and ride it for 10 years, will probably stick with carrying spare tubes.

  • Not for mountain bikes (Score:5, Insightful)

    by Puls4r ( 724907 ) on Wednesday March 17, 2021 @09:29AM (#61167826)
    These tires are not for mountain bikes. If you think they are, I challenge you to ride them through some mud. Not only will you sink, the mud will end up inside the tire and hilarity will ensue.

    These tires are for long-wear low-maintenance solutions for rental style bikes in urban and paved environments. Any other uses will result in varying degrees of failure. For instance - riding these in the sand would be problematic.

    • Re:Not for mountain bikes (Score:4, Insightful)

      by cahuenga ( 3493791 ) on Wednesday March 17, 2021 @10:33AM (#61168018)
      Not to mention completely losing the ability to change tire pressure to compensate for different trail conditions

    • OMG Puls4r you're so much smarter than the tens-of-thousands of people who've spent millions of person-hours' lifespan on this project! Not one of them has ever heard of this "mud" of which you speak, thank you so much! The stockholders of Goodyear owe you a huge debt for saving them wasting another cent on this nightmare. And gawd knows no one at NASA, Goodyear, or even in Ohio (Glen Research Center) ever thought to try this on sand! It amazes me, how they could've missed this. BACK TO THE DRAWING BOA

    • You should not ride mountain bikes on muddy trails as it destroys the trail. Wait a week after rain. Unless you live in England, in which case you'll need tires. Ahem, TYRES. ðY(TM)

  • What is new? (Score:3)

    by DrSpock11 ( 993950 ) on Wednesday March 17, 2021 @10:00AM (#61167910)

    Nitinol [wikipedia.org] is not a new discovery and neither is the idea of making tires out of it.

    TFA and TFS doesn't really specify what is new about this design other than calling it NiTinol+.

  • Great for EV (Score:3)

    by iamhassi ( 659463 ) on Wednesday March 17, 2021 @11:19AM (#61168170) Journal
    This would be great for scooters or anything that uses a hub motor where the tire is permanently attached to the electric motor. Currently they use solid rubber for the tires on hub motors but that’s expensive and rides rough.

  • Their website high on hype, but a bit low on substance. I see confusion here in the comments about how these tires will be terrible in mud and sand, and how will they grip the road? Nearly all their photos show the naked metal weave, because that's what's cool. However, if you read their FAQ, they explain that the tire will be covered in a replaceable tread. On the FAQ page, there is one photo of a tire that appears to have a thin covering.

    For a long-distance touring tire, these could be great, even with a

  • Assuming a 700C bicycle tire:
    1. Can it take a 90 degree corner at 25+ miles per hour, as you would in a criterium or circuit race, without dumping your ass on the pavement?
    1a. For that matter, what about high-speed technical descents, like descenting a mountain?
    2. On wet roads, does it still have the same traction as, say, a Continental 5000?
    3. On wet roads, does that open mesh accumulate mud and dirt and what-not from the road?
    4. What are the wear characteristics like? Compare, again, to a tire like t

    • Assuming a 700C bicycle tire: 1. Can it take a 90 degree corner at 25+ miles per hour, as you would in a criterium or circuit race, without dumping your ass on the pavement? 1a. For that matter, what about high-speed technical descents, like descenting a mountain? 2. On wet roads, does it still have the same traction as, say, a Continental 5000? 3. On wet roads, does that open mesh accumulate mud and dirt and what-not from the road? 4. What are the wear characteristics like? Compare, again, to a tire like the Continental 5000. 5. With a pneumatic tire you can adjust ride characteristics for various conditions by varying air pressure. Does this have superior overall characteristics considering you're stuck with however it's made? 6. What do these weigh? Not only is overall weight of the bike important (mainly when climbing, but also for acceleration), but having a heavier overall front wheel affects overall handling of the bike, especially at high speeds.

      The answer to all of your questions is pretty much it's the same. The tire doesn't change. You're still riding rubber on road. You'll probably use the exact same tires you use today in future models. You just don't have an inflatable innertube that could rupture. You'd get consistent pressure, which I imagine can be tuned to your ideal. Its an interesting idea and I look forward to not inflating a tire again, but only if the weight is similar and the performance is the same.

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