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Michelin Airless

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Re: Michelin Airless

#201

Post by loeg »

bluGill wrote: post #152
kbenson wrote: post #64

Earlier quoted context omitted.

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.

TPMS doesn't alert until tires are something like 25-30% under pressure, which is pretty severe.[1]

[1]: https://www.nhtsa.gov/sites/nhtsa.gov/files/fmvss/TPMSfinalr... (page 10)

Re: Michelin Airless

#202

Post by thefounder »

noobermin wrote: post #200
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. (…

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.

Re: Michelin Airless

#203

Post by mcguire »

ggreer wrote: post #179
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.

Where are you getting those figures? When I look up the stats for the 2021 Accord I see weights ranging from 3,150-3,446lbs.[1] Really though, the Civic and Accord aren't competing with the Model 3. They're front wheel drive. They have less power and torque. They use struts for the front suspension. All of these measures save significant weight (and cost). That's why I picked the BMW 3 series. It's similar size, perf…

And the GMC Yukon is 5500-5800 lbs, which is what I expect the original comment to be making a comparison with.

Re: Michelin Airless

#204

Post by loeg »

bkanber wrote: post #163
bluGill wrote: post #152

Earlier quoted context omitted.

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.

My cold tire pressure is supposed to be 33PSI, my TPMS doesn't alert until it's below 28PSI, so there is a significant delta still. The TREAD law does not specify when TPMS must alert, other than the tire being 'significantly underinflated'.

The NHTSA has determined that the requirement is that TPMS alerts for 25% underinflation across any combination of tires, or 30% underinflation in a single tire.[1] Originally they wanted 20-25%, but determined that cheap TPMS sensors were not good enough to meet that threshold and did not want to impose the cost of better sensors.

[1]: https://www.nhtsa.gov/sites/nhtsa.gov/files/fmvss/TPMSfinalr...

Re: Michelin Airless

#205

Post by mcguire »

zubiaur wrote: post #73
_fat_santa wrote: post #48

Earlier quoted context omitted.

> My friend was driving and looked a the flat front tire and said "I'm glad I have a spare". I look at the flat back tire and said "Unless you have two, we're still going to need assistance. I did this one time. Ran over a pothole and bottomed out. As I'm replacing my front tire I look to my rear tire and see that it's also flat. That wasn't even the cherry on top. At that point I had my front wheel off and tried put…

Been there, with a GM with a similar issue. The manual stated something about putting the spare on a rear, then, taking the good rear and putting it in the front. The rotors on the rear were smaller and could accommodate the spare. Obviously a moot point if one has two blown tires.

If you can't fix the bug, document the work-around.

Re: Michelin Airless

#206

Post by cat199 »

kazinator wrote: post #176
xxpor wrote: post #97

Earlier quoted context omitted.

Hmm, why water filled? I can't think of any advantages, but can think of downsides such as a massive increase in unsprung weight.

A disadvantage is that only the rubber absorbs impacts, since the fluid is incompressible for all intents and purposes.

... but for 'intensive purposes' on the other hand the story is less clear

Re: Michelin Airless

#207

Post by fischert »

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.

This is why regulation is needed. States do not allow any kind of car on the streets. But often car manufacturers say it will threaten economy and labor.

Re: Michelin Airless

#208

Post by mcguire »

ableal wrote: post #137
jaclaz wrote: post #39

Previous related thread here (about one month ago): https://news.ycombinator.com/item?id=28537549

Thanks. Second comment: """ I am an engineer working in the tire industry (throwaway is needed here). The Michelin "Tweel" IP was actually acquired when Michelin bought BF Goodrich 31 years ago. Goodrich developed the concept as a replacement for compact spare tires, doing the initial R&D in the 1980s. Every 3--5 years Michelin has a press release like this, and the technology is always 3--5 years away from release.…

Which brings up the one ideal use for these that hasn't been mentioned: spare tires, if you can make them narrower with the same load capacity.

Re: Michelin Airless

#210

Post by bkanber »

OnlineGladiator wrote: post #193
bkanber wrote: post #180

Earlier quoted context omitted.

What? I don't understand what you mean by that.

There's no reason to assume this is a solvable problem, just because it's a new field. I remember when cold fusion was considered inevitable. You don't actually have any reason to assume it will happen other than blind optimism.

... you don't actually have any reason to assume it won't happen other than blind pessimism. So let's just agree to disagree.
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