Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Michelin Airless

michelin.com

Post reply on HN
Print view View original

61–70 of 316 posts

Re: Michelin Airless

#61

Post by Steltek »

intrasight wrote: post #34
Yizahi wrote: post #16

I don't worry about punctures at all, despite living in a country with a shitty roads. What I worry about A LOT is a catastrophic collision of tire with a 90 degree sharp pothole edge, often made by roadworkers before doing point repair, which potentially can destroy tire irreparably. I wonder if these tires are better protected against such impacts, and just looking at them it seems they are - no side walls which ar…

Other comments here say that production tires will have sidewalls to protect the spokes and keep out rocks. If so, I'm a bit disappointed since I like the look of the spokes. Regarding catastrophic collision with sharp edge, I think these tires will be susceptible as well. If it's enough of a bump to "bottom out", it's going to dent the rim. Also, your comment about potholes reminded me of a time that I was driving w…

Are those spokes or springs? My mind had defaulted to "springs" given the zipzag shape and the typical function of a pneumatic tire. It didn't occur to me that they could function like spokes, where the vehicle hangs off the upper springs, until I read your comment. Why would the rim be so large and solid?

Re: Michelin Airless

#62

Post by hammock »

_fat_santa wrote: post #48
intrasight wrote: post #34

Earlier quoted context omitted.

Other comments here say that production tires will have sidewalls to protect the spokes and keep out rocks. If so, I'm a bit disappointed since I like the look of the spokes. Regarding catastrophic collision with sharp edge, I think these tires will be susceptible as well. If it's enough of a bump to "bottom out", it's going to dent the rim. Also, your comment about potholes reminded me of a time that I was driving w…

> 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…

How do you like the Stinger? I saw one of those the other day and did a double take on the Kia logo.

Re: Michelin Airless

#64

Post by kbenson »

bkanber wrote: post #28
markild wrote: post #24

Interesting that they say nothing about consumption. I would expect them to be less fuel efficient, but having some number to go by would be nice.

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 just don't, and I don't expect that to change meaningfully.

Re: Michelin Airless

#65

Post by kadoban »

rbanffy wrote: post #55
mabub24 wrote: post #12

Earlier quoted context omitted.

Completely guessing, but I wonder if they designed the "spoke" baffles to pinch in under the load and thus expel any stones that might fit between them, like a pebble squeezed between your two fingers and shooting out.

A pebble shooting out of the upper side of a tire of a car at 250 km/h is probably as bad as a bullet. Probably worse.

So about the same as a pebble that gets stuck in treads or kicked up by same? Definitely better than a bullet though just by nature of lower speed, what it's made of and because of its poor aerodynamics.

Re: Michelin Airless

#66

Post by ggreer »

KptMarchewa wrote: post #30
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. (…

EVs are usually much heavier than gas cars.

I don't think that's true anymore. For example, the Tesla Model 3 weighs anywhere from 3,552-4,072lbs depending on the trim level.[1] (The heaviest is the Model 3 Performance which has the biggest battery, motors, and wheels.) The BMW 3 series is 3,582-4,138lbs depending on the exact model and trim.[2]

Gas cars don't have big heavy batteries but they do have big heavy engine blocks and more complicated (heavier) drivetrains.

1. https://en.wikipedia.org/wiki/Tesla_Model_3

2. https://www.caranddriver.com/bmw/3-series/specs

Re: Michelin Airless

#67

Post by 725686 »

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?

Re: Michelin Airless

#68

Post by bkanber »

amelius wrote: post #60
bkanber wrote: post #53

Earlier quoted context omitted.

Tweels are probably too heavy to be viable on bicycles.

https://www.bridgestone.com/corporate/news/2017041701.html

> The companies will advance feasibility studies seeking to make this new tire available in market by 2019.

Given that I haven't seen tweels for bicycles yet, I assume the feasibility studies did not go well.

It also looks like they also announced that bicycle tweels were 'coming soon' nearly two years ago: https://jalopnik.com/bridgestone-says-airless-tires-are-comi...

Re: Michelin Airless

#69

Post by mitigating »

ggreer wrote: post #66
KptMarchewa wrote: post #30

Earlier quoted context omitted.

EVs are usually much heavier than gas cars.

I don't think that's true anymore. For example, the Tesla Model 3 weighs anywhere from 3,552-4,072lbs depending on the trim level.[1] (The heaviest is the Model 3 Performance which has the biggest battery, motors, and wheels.) The BMW 3 series is 3,582-4,138lbs depending on the exact model and trim.[2] Gas cars don't have big heavy batteries but they do have big heavy engine blocks and more complicated (heavier) driv…

BMW is a particularly heavy sedan. The Honda Civic is 2877 to 3126. Even the Golf R which has a rear diff, DCT, and a 2.0 turbo is only 3100 pounds.

Re: Michelin Airless

#70

Post by gibolt »

flurie wrote: post #32
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. (…

EVs are quite heavy for their footprint due to the weight of the batteries.

This will change with improved batteries, charging infrastructure, and shrinking EV tech. By the time this could hit the market, hopefully the weight difference would be less stark.
Post reply on HN