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Michelin Airless

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Re: Michelin Airless

#151

Post by bkanber »

kbenson wrote: post #64
bkanber wrote: post #28

Earlier quoted context omitted.

As a general rule, tweels are worse for fuel consumption -- they are both heavier and have more rolling resistance. (Edit: weight automatically adds rolling resistance, but so does flexion, which tweels have more of. So tweels are a double-whammy for fuel economy.)

I wonder how that breakdown works for under inflated and overinflated tires, and what percentage of the nations tires are in that state at any moment? For a consumer product like this I think it's probably more important to compare the common case than the optimal case, because I know my tires often aren't in an optimal state, and as much as we could save as a nation by making sure tires were inflated correctly, we j…

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.

Re: Michelin Airless

#152

Post by bluGill »

kbenson wrote: post #64
bkanber wrote: post #28

Earlier quoted context omitted.

As a general rule, tweels are worse for fuel consumption -- they are both heavier and have more rolling resistance. (Edit: weight automatically adds rolling resistance, but so does flexion, which tweels have more of. So tweels are a double-whammy for fuel economy.)

I wonder how that breakdown works for under inflated and overinflated tires, and what percentage of the nations tires are in that state at any moment? For a consumer product like this I think it's probably more important to compare the common case than the optimal case, because I know my tires often aren't in an optimal state, and as much as we could save as a nation by making sure tires were inflated correctly, we j…

TPMS has been law in the US since 2007. People might be driving around with under inflated tires, but there is a light on if they are.

Re: Michelin Airless

#153

Post by Chris2048 »

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.

Surely the ability to recycle/repurpose an old tyre matters more than the flats, so I'm not sure how this helps.

Also, I see the biggest concern as degradation of tyres contributing to rubber-dust pollution: "according to the UK government, and they are the second largest source of microplastic pollutant in oceans after single-use plastic"

Seems like it would be better to find an eco-friendly alternative to tyre rubber instead. If this design allows that (e.g. by allowing tyre materials that aren't as stretchy as an inflatable would need to be) I'm all for it, but that's a more complicated definition of "good for environment", dependant on other tech being developed.

Re: Michelin Airless

#154

Post by bkanber »

OnlineGladiator wrote: post #74
bkanber wrote: post #26

Earlier quoted context omitted.

At some point they will be viable... whether this is that point or not is yet to be seen.

> At some point they will be viable Why do you assume this?

Because this is primarily a materials science problem, and we are still novices at materials science.

Re: Michelin Airless

#155

Post by dylan604 »

dsr_ wrote: post #128
hollander wrote: post #116

Earlier quoted context omitted.

I use nitro oxygen in my tyres. Pressure problems are gone.

The Earth's atmosphere is about 80% nitrogen and a little less than 20% oxygen, with some carbon dioxide, argon, variable amounts of water vapor, and some pollution. What's "nitro oxygen", then?

https://www.tireamerica.com/resource/nitrogen-vs-oxygen-for-...

That at least helps with some of the logic. However, doesn't directly answer what "nitro oxygen" is. Guessing some sort of slang. It's definitely not a scientific phrase. Nitrogen oxide or something maybe too much for grease monkies so they call it nitro oxygen??? just guessing.

Re: Michelin Airless

#157

Post by 8ytecoder »

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. (…

Don't get me wrong - I'd expect Michelin to have done some testing to see NVH is within tolerance levels right?

Airless is really close to working for bikes. If I were commuting on a bike now I'd be comfortable going for it. The downsides - painfully hard installation, uphill resistance, ...etc. - will be worth it.

Re: Michelin Airless

#158

Post by kube-system »

_ea1k wrote: post #150
kube-system wrote: post #99

Earlier quoted context omitted.

The Civic is 2 inches shorter and 2 inches narrower than the Model 3, but it actually has a larger interior volume by one cubic foot. Size up to the Accord which is 8 inches longer and a half inch wider than a Model 3 (and 9ft^3 more interior space), and it still only weighs 3131-3362 lbs.

The 3 has at least 5 cubic feet more in cargo space than the Civic. In practice there is a pretty big difference between those two cars.

The Civic and 3 both have 15 ft^3 of cargo space according to the EPA.

Regardless, the Accord dwarfs it and supports the above point that the Model 3 is a heavy car, and the BMW 3 series is heavy because it was built to have a premium feel as a design priority, not because it is ICE.

Re: Michelin Airless

#159

Post by bananapear »

dsr_ wrote: post #128
hollander wrote: post #116

Earlier quoted context omitted.

I use nitro oxygen in my tyres. Pressure problems are gone.

The Earth's atmosphere is about 80% nitrogen and a little less than 20% oxygen, with some carbon dioxide, argon, variable amounts of water vapor, and some pollution. What's "nitro oxygen", then?

Maybe just nitrogen? Costco inflates tyres with nitrogen. The pair of tyres on my vehicle inflated with nitrogen don’t seem to lose pressure, the other two need topping up occasionally.

Re: Michelin Airless

#160

Post by speedgoose »

725686 wrote: post #67
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. (…

Maybe the noise they generate is good for EVs which are dangerously quiet for pedestrians?

You can ear an EV very well, the rolling noise and the wind noise is difficult to miss. Of course if the EV is driven very slowly it's not noisy unless it has a fake sound like many does, but it's not very dangerous either.
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