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Michelin Airless

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Re: Michelin Airless

#221

Post by simonebrunozzi »

thefounder wrote: post #202
noobermin wrote: post #200

Earlier quoted context omitted.

Sorry for the conversation pivot, but this attitude sucks and is terrible for climate change and was decided wholesale by suppliers. While SUVs are leading sales in the US, it was the decision by car manufacturers to discontinue sales of anything other than SUVs in the US. That you say, "well these wheels which would reduce waste aren't useful for Americans," they are partly not useful because the car industry here p…

Nah...americans like big cars and manufacturers followed the sales! Even worse, europeans started to like big cars too...I just don't get why people like to drive big SUVs in the city.

Nah. SUVs above a certain weight pay less taxes [0], that's why automakers aggressively marketed them for decades and finally managed to convince Americans that SUVs are cool.

[0]: https://www.irs.gov/publications/p946

Re: Michelin Airless

#222

Post by bkanber »

kbenson wrote: post #212
bkanber wrote: post #151

Earlier quoted context omitted.

Overinflated tires will always have better economy than underinflated, all other things being equal. My guess is the average vehicle owner could improve overall fuel economy by about 0.5-1.0% by making sure their tires are at the correct pressure.

So, my thought when I said that was back when Obama mentioned keeping tires inflated correctly and getting tuneups to reduce oil consumption, and looking into that lead to this[1], which puts it at 0.6% on average, but up to 3% in specific cases. So I guess the question is how does 0.6% fuel economy loss on average for current tires compare to the loss in efficiency for using a Tweel, but according to some data from…

Funny -- I presented a paper at that very same conference! Mine was 2011-01-0755.

The money shot is here. Note that '5.5 kg/ton' refers to the rolling resistance of the tire.

> At this point the 5.5 kg/ton value is still only a design target, and this study serves mainly to confirm the environmental value of achieving that target.

Essentially, this conclusion is tautological. "If there were a tweel that had better rolling resistance than the best pneumatic tire on the market, then it will have a better fuel economy and environmental impact." Obviously!

I seriously doubt Michelin's tweel is anywhere close to that 5.5 kg/T mark. It's more likely something like 12 kg/T.

The purpose of this particular paper is not to show that tweels are better environmentally, it is to show an analytical framework for calculating the full-lifecycle environmental impact of tweels vs tires. Sort of like a "here are the equations, plug in real numbers later" kind of thing.

Re: Michelin Airless

#223

Post by kbenson »

bkanber wrote: post #222
kbenson wrote: post #212

Earlier quoted context omitted.

So, my thought when I said that was back when Obama mentioned keeping tires inflated correctly and getting tuneups to reduce oil consumption, and looking into that lead to this[1], which puts it at 0.6% on average, but up to 3% in specific cases. So I guess the question is how does 0.6% fuel economy loss on average for current tires compare to the loss in efficiency for using a Tweel, but according to some data from…

Funny -- I presented a paper at that very same conference! Mine was 2011-01-0755. The money shot is here. Note that '5.5 kg/ton' refers to the rolling resistance of the tire. > At this point the 5.5 kg/ton value is still only a design target, and this study serves mainly to confirm the environmental value of achieving that target. Essentially, this conclusion is tautological. "If there were a tweel that had better ro…

Ah, nice to know, and thanks for giving a professional's assessment of what's being said. :)

Re: Michelin Airless

#224

Post by moneywoes »

bkanber wrote: post #13

Former automotive engineer chiming in. "Tweels" have been around a long time, but have always failed in terms of "NVH" (noise, vibration, harshness). Michelin is claiming that this generation of tweels are appropriate for passenger cars, which means that they think they've solved the NVH problem. They seem to be marketing these alongside EVs, I wonder if they're only really intended for lighter, compact-style cars. (…

Is there a reason this technology is not used on bikes which weigh a lot less?

Re: Michelin Airless

#226

Post by DoingIsLearning »

nonameiguess wrote: post #218
thefounder wrote: post #202

Earlier quoted context omitted.

Nah...americans like big cars and manufacturers followed the sales! Even worse, europeans started to like big cars too...I just don't get why people like to drive big SUVs in the city.

I'm not trying to defend myself or anything since I don't even have a car, but when I did, it was always an SUV. It wasn't so much a matter of preference as necessity. I'm not exactly huge, only 6'2", but if I try to drive my wife's GTI, I'm hunched over and hitting my head on the ceiling. Only way to do it is leaning severely back with the seat reclined. Trying to be a backseat passenger in an average sedan is compl…

The interior space of an MPV is typically bigger than an SUV.

Considering the sales numbers of MPVs, it would seem that the argument you make is not what is pushing the disproportionate commercial success of SUVs.

Re: Michelin Airless

#227

Post by andylynch »

goodmachine wrote: post #209

Fun fact, almost half of particulate road pollution comes from conventional tyres. Not clear whether these new airless tyres will help or worsen that. More resistance = more wear, I would assume. Anyone? https://www.imperial.ac.uk/news/195595/worlds-first-device-c...

I head looked at these before, and only now noticed they that talk about retreading/ recharging treads by 3D printing- this doesn’t directly address the particulate issue but is a very interesting idea for reducing the waste from worn tyres more generally.

Re: Michelin Airless

#228

Post by bkanber »

kbenson wrote: post #223
bkanber wrote: post #222

Earlier quoted context omitted.

Funny -- I presented a paper at that very same conference! Mine was 2011-01-0755. The money shot is here. Note that '5.5 kg/ton' refers to the rolling resistance of the tire. > At this point the 5.5 kg/ton value is still only a design target, and this study serves mainly to confirm the environmental value of achieving that target. Essentially, this conclusion is tautological. "If there were a tweel that had better ro…

Ah, nice to know, and thanks for giving a professional's assessment of what's being said. :)

:) Not a problem! Your experience hangs a lantern on one of the problems in academia.

The authors of that paper did not intend to mislead -- this paper was published in 2011, likely written in 2010, only a handful of years after Michelin's unveiling of their gen 1 tweel design. To me, having been in the authors' position, I can easily tell what the true purpose of the paper actually was (the analytical procedure). But the authors had a secondary purpose driven by 'hype', almost, you could even call it click-bait: they wanted to make the tweel exciting so that other researchers would get interested in it and continue the work. One way to do that is by showing, from a materials perspective, that it is theoretically possible to design a tweel with a low rolling resistance, and given that, it's possible that tweels will be better for the environment over the full-lifecycle, including manufacturing and materials. And sure, this absolutely did/does deserve more research. However, the other issues with tweels, like NVH/comfort/etc, were 'out-of-scope' for that paper, and so they ignored those. Solving for those issues is what makes that 5.5 kg/T figure difficult/possibly impossible to attain.

When these papers are confined to academia, it all works out, because most of the people who read your paper are other people who are writing papers, and they get it. But once these types of papers are picked up by the press/media/general populous, they can be very quickly misinterpreted!

(To be clear, you didn't do anything wrong here, I'm just griping a bit about academia and pretending like I'm 'adding context' ;)

Re: Michelin Airless

#229

Post by andylynch »

AStrangeMorrow wrote: post #124
modeless wrote: post #75

I am skeptical that these will be better for the environment. Maybe there will be fewer tires discarded due to flats, but the tires will weigh more. That's more material discarded per tire and more energy to drive them around.

Maybe I am wrong, but I think I've red somewhere that these are made to be re-threaded. Meaning when the outer layer get damaged with use, instead of changing the whole tire, just the outer part can be replaced. Not too sure how that works though. If that is the case, it should help reduce the amount of waste by a lot. Plus even if these new tires are heavier, I doubt they are 10 times heavier either. I'd be surprise…

They call it ‘recharging’ on this page. They even propose converting between summer/winter by reprinting the tread.

Re: Michelin Airless

#230

Post by laurent123456 »

nonameiguess wrote: post #218
thefounder wrote: post #202

Earlier quoted context omitted.

Nah...americans like big cars and manufacturers followed the sales! Even worse, europeans started to like big cars too...I just don't get why people like to drive big SUVs in the city.

I'm not trying to defend myself or anything since I don't even have a car, but when I did, it was always an SUV. It wasn't so much a matter of preference as necessity. I'm not exactly huge, only 6'2", but if I try to drive my wife's GTI, I'm hunched over and hitting my head on the ceiling. Only way to do it is leaning severely back with the seat reclined. Trying to be a backseat passenger in an average sedan is compl…

What? I'm about the same height and drive a sedan just fine, and it's comfortable and safe. I don't know how small your wife's car is, but I've never been in one so small that I'm bumping my head in the ceiling, that would be weird.
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