Airless tires making inroads, off-road

by
in hardware on (#23VZG)
story imageIf you've never driven a Tweel, it might be time to try one (or four). It is basically an airless tire held up with rubber spokes. Michelin says the spokes provide a unique energy transfer that reduces bounce associated with pneumatic tires while offering two to three times the wear life. And because the tires have no air, you never have to adjust the air pressure or risk getting a flat. Tweels are best suited for low-speed vehicles that don't have suspensions and are prone to flats, such as lawnmowers and skid-steer loaders used on construction sites, but Michelin isn't ruling out their use on other vehicles in the future.

Different companies make tires that don't use air, including Bridgestone and Goodyear, and they go by different names: Non-pneumatic tires (NPT), airless tires, or run-flat tire are the most common. The first time I drove NPT tires was in 2014, I was floored by how the tires absorbed the bumps and seemingly rolled without noise or resistance. The product manager talked about how these "Terrain Armor" NPTs won't go flat (punctures) and won't get stuck in mud because the honeycomb design actually pushes mud out. Of course, they also have some drawbacks, such as noise and vibration at higher speeds.
Reply 7 comments

Gripe (Score: 2, Informative)

by fishybell@pipedot.org on 2016-12-05 15:09 (#243E5)

As many people on the internet, I mostly comment to gripe (not really, but sometimes yes).

Run-flat tires use air. They merely have a system - ribs like these tires have, reinforced sidewalls, reinforced tread liners, and/or less commonly a smaller non-pneumatic tire on the inside - to allow them to continue working in some sense when the air is let out, typically through a puncture or leak.

Also, I expect commercial versions on non-pneumatic tires to not be open-air like those pictured. I would expect there to be dangerous situations where rocks could get lodged inside and shot out at high velocities under pressure.

Alright, I'm done griping.

Re: Gripe (Score: 1)

by koen@pipedot.org on 2017-02-05 18:53 (#2BK2S)

I expect commercial versions on non-pneumatic tires to not be open-air like those pictured.
Seems to me the tires pictured are the commercial version: http://www.michelintweel.com/tweel-SSL-AllTerrain.html

Re: Gripe (Score: 1, Informative)

by Anonymous Coward on 2017-02-28 22:18 (#2E9F2)

As you say, run-flat tires are normal car tires (with air) that are also capable of being used without air for some relatively short distance (50 miles?).

The Tweel is an airless tire-wheel combination with rubber tread elements and a polymer wheel that flexes to absorb bumps. Michelin has been pushing these for low speed applications for a number of years now. Small Tweels have been made for wheelchairs, probably much better than solid rubber or pneumatic tires in this application. Large ones for construction equipment as shown in the lead photo where they probablly replaced pneumatic tires. In other cases they might replace solid rubber tires (commonly used inside factories), for example, a fork lift that goes outdoors.

While Michelin have also been doing research internally and externally (maybe at Clemson U?) to make the Tweel suitable for normal cars this hasn't happened yet. Current Tweels are not low rolling resistance and transmit much more vibration than ordinary pneumatic tires, so they are unlikely to replace very many car & light truck tires in the near future.

Solid tires have been around for a while... (Score: 1, Interesting)

by Anonymous Coward on 2016-12-12 19:36 (#250BT)

But manufacturers don't like them because they last an exceptionally long time, and are perfect for many applications that utilize
very expensive tires(such as tractors).

Flexing? (Score: 0)

by Anonymous Coward on 2017-01-06 04:18 (#27VPA)

They probably can't handle speed too well, so probably no application on cars?

Re: Flexing? (Score: 1)

by fishybell@pipedot.org on 2017-01-30 16:31 (#2ATNK)

Normal car tires flex in about the same amount. If they didn't flex they would be very hard and seriously impact handling from both a ride-harshness standpoint and a grip standpoint (harder rubber = less grip). The flexing also allows for a larger contact patch with the road.

Wrong expectations (Score: 2, Funny)

by dannyb@pipedot.org on 2023-06-16 15:16 (#6C7NX)

I'm not entirely convinced about airless tires. I think the expectations might be a bit over inflated.