6 ms·

At first glance I can’t tell how this overcomes the problems of the “Tweel” because it looks just like it (https://en.m.wikipedia.org/wiki/Tweel https://en.m.wi

At first glance I can’t tell how this overcomes the problems of the “Tweel” because it looks just like it (https://en.m.wikipedia.org/wiki/Tweel https://en.m.wikipedia.org/wiki/Tweel). Also made by Michelin, Tweels are really loud at high speed and they easily pick up stuff in their open sidewall structure leading to out of balance issues at speed-vibration. So they’ve mostly been deployed in low-speed, low-debris environments, like on forklifts in warehouses. This looks like a different structural fin design, so maybe they’ve fixed the noise issue, but you still have an open sidewall to fill with mud, ice, rocks, etc...

eganist 7y ago
Something advanced by the tire's lead evangelist at Michelin: > "If you have a load on the tire and you cut all the spokes at the bottom, you will see that nothing will change, demonstrating that the load is carried by the top of it, not by the under parts." Other airless tires, he said, often carry the load at the bottom of the tire, which is very inefficient and causes extra heating due to compression.
- zrobotics 7y ago
  That just emphasizes the internal load distribution, it doesn't address concerns about mud/ice filling the sidewall. Sadly this is article is just a press release with very little technical information. Tires like these already exist for industrial equipment, Michelin does need to address these very real concerns. I am also concerned about the ecological impacts, it appears the tire uses more rubber than conventional tires, the only way this isn't worse is if it is safely recappable. It may be, but again the article doesn't state so.
  - piva00 7y ago
    Can't they just cover the sidewall like a normal tyre? If needed to inspect the inner structure just make it removable/replaceable.
    - zrobotics 7y ago
      If the sidewalls are covered, how can they mold the internal structure so it isn't attached to the sidewall? Because if it is, it can't flex, so the tire will be harder than a rock.
TickleSteve 7y ago
From your wiki link.... "Although it is acknowledged that the initial prototype automotive Tweel tires did demonstrate flaws with regard to noise and high speed vibration[5] and produced 5 percent more friction compared to a radial tire,[3] these early issues were resolved in subsequent prototypes, and current automotive Tweel prototype products have been shown to be well behaved and reliable."
eliben 7y ago
I wonder why they can't just close off the outer walls with rubber same as in regular tires.
- matt-attack 7y ago
  Weight? Maybe they’re already too heavy with all those internal spokes. Sidewalls would just add more weight.
- masklinn 7y ago
  I guess it would be very difficult to create the internal structure, and especially keep the internal structure separated from the sidewall (which would make the entire thing undesirably rigid)?
  - Doxin 7y ago
    Regular tires are already many-layered laminates, Gluing on a sidewall on this tire shouldn't be technically all that hard. My guess is it'd keep the air in which you don't want with an airless tire.
    - logfromblammo 7y ago
      Why not? Just add a valve that allows air out if the interior pressure rises more than x% above ambient atmospheric pressure, and allows air in through a filter if it's more than y% below. It wouldn't be that much more complex than the stem valves already added to tires. The primary goal is to keep contaminants out of the interior tire structure, but a secondary marketing goal should probably be to make them look like normal tires at first glance. Wrapping the internal structure in something that looks like "normal tire" serves both.
      - Doxin 7y ago
        Once you add in valves to let air in and out you run into the exact same fouling problems. Snow, small pebbles, road grit, any one of a number of things is at some point going to get sucked into that cavity. Normal stem valves avoid the problem by having a screw-on cap, which'd hardly work for a valve that needs to be passing air all the time.
joenathanone 7y ago
I wonder what happens if you drive through mud, isn't it going to clog up the openings?
- MrMember 7y ago
  Ice and snow as well.
volume-scale 7y ago
There's nothing that says the sidewalls have to be open celled.
- deleted 7y ago
  [deleted]
pwinnski 7y ago
They'll be testing in Michigan, so they should be dealing with that issue pretty quickly!
deleted 7y ago
[deleted]

eganist 7y ago

Something advanced by the tire's lead evangelist at Michelin: > "If you have a load on the tire and you cut all the spokes at the bottom, you will see that nothing will change, demonstrating that the load is carried by the top of it, not by the under parts." Other airless tires, he said, often carry the load at the bottom of the tire, which is very inefficient and causes extra heating due to compression.

zrobotics 7y ago
That just emphasizes the internal load distribution, it doesn't address concerns about mud/ice filling the sidewall. Sadly this is article is just a press release with very little technical information. Tires like these already exist for industrial equipment, Michelin does need to address these very real concerns. I am also concerned about the ecological impacts, it appears the tire uses more rubber than conventional tires, the only way this isn't worse is if it is safely recappable. It may be, but again the article doesn't state so.
- piva00 7y ago
  Can't they just cover the sidewall like a normal tyre? If needed to inspect the inner structure just make it removable/replaceable.
  - zrobotics 7y ago
    If the sidewalls are covered, how can they mold the internal structure so it isn't attached to the sidewall? Because if it is, it can't flex, so the tire will be harder than a rock.

TickleSteve 7y ago

From your wiki link.... "Although it is acknowledged that the initial prototype automotive Tweel tires did demonstrate flaws with regard to noise and high speed vibration[5] and produced 5 percent more friction compared to a radial tire,[3] these early issues were resolved in subsequent prototypes, and current automotive Tweel prototype products have been shown to be well behaved and reliable."

eliben 7y ago

I wonder why they can't just close off the outer walls with rubber same as in regular tires.

matt-attack 7y ago
Weight? Maybe they’re already too heavy with all those internal spokes. Sidewalls would just add more weight.
masklinn 7y ago
I guess it would be very difficult to create the internal structure, and especially keep the internal structure separated from the sidewall (which would make the entire thing undesirably rigid)?
- Doxin 7y ago
  Regular tires are already many-layered laminates, Gluing on a sidewall on this tire shouldn't be technically all that hard. My guess is it'd keep the air in which you don't want with an airless tire.
  - logfromblammo 7y ago
    Why not? Just add a valve that allows air out if the interior pressure rises more than x% above ambient atmospheric pressure, and allows air in through a filter if it's more than y% below. It wouldn't be that much more complex than the stem valves already added to tires. The primary goal is to keep contaminants out of the interior tire structure, but a secondary marketing goal should probably be to make them look like normal tires at first glance. Wrapping the internal structure in something that looks like "normal tire" serves both.
    - Doxin 7y ago
      Once you add in valves to let air in and out you run into the exact same fouling problems. Snow, small pebbles, road grit, any one of a number of things is at some point going to get sucked into that cavity. Normal stem valves avoid the problem by having a screw-on cap, which'd hardly work for a valve that needs to be passing air all the time.

joenathanone 7y ago

I wonder what happens if you drive through mud, isn't it going to clog up the openings?

MrMember 7y ago
Ice and snow as well.

volume-scale 7y ago

There's nothing that says the sidewalls have to be open celled.

deleted 7y ago
[deleted]

pwinnski 7y ago

They'll be testing in Michigan, so they should be dealing with that issue pretty quickly!

deleted 7y ago

[deleted]