The Tweel (a portmanteau of tire and wheel) is an airless tire design concept developed by the French tire company Michelin. Its significant advantage over pneumatic tires is that the Tweel does not use a bladder full of compressed air, and therefore it cannot burst, leak pressure, or become flat. Instead, the Tweel assembly’s inner hub connects to flexible polyurethane spokes which are used to support an outer rim and these engineered compliant components assume the shock-absorbing role provided by the compressed air in a traditional tire.

The Tweel airless tire design


The Tweel consists of a band of conventional tire rubber with molded tread, a shear beam just below the tread that creates a compliant contact patch, a series of energy-absorbing polyurethane spokes, and an integral inner rim structure. Both the shear beam and the polyurethane spokes can be designed to provide a calibrated directional stiffness in order that design engineers are able to control both how the Tweel handles and how it handles loads. The inner hub structure may be either rigid or compliant,[1] depending on the application requirements, and as such may contain a matrix of deformable plastic structures that flex under load and subsequently return to their original shape. By varying the thickness and size of the spokes, Michelin can manipulate the design elements to engineer a wide array of ride and handling qualities. The tread can be as specialized as any of today’s tires and is replaceable when worn.[2]

Benefits and drawbacks

Potential benefits of the Tweel include not only the obvious safety and convenience of never having flat tires, but also, in automotive applications, the Tweel airless tire has the potential to be able to brake better – a significant performance compromise that is inherent to pneumatic tires. Unlike a pneumatic tire, a Tweel can be designed to have high lateral stiffness while simultaneously having low vertical stiffness. This can be achieved because, in the design elements of a Tweel, the vertical and lateral stiffness are not inseparably linked and can thus be optimized independently. Because there is no air bladder under the tread, tread patterns can, if desired, even incorporate water evacuation through holes in the design thus eliminating or significantly reducing hydroplaning. Michelin expects the tread to last two to three times as long as a conventional tire.[3] Because the tread rubber around the outer circumference is replaceable when worn (as opposed to disposing of a whole worn tire), the potential environmental impact of a Tweel airless tire can be less than that of a conventional pneumatic tire.

Tweel is useful for: “vehicles that don’t have suspensions like lawn mowers – those low speed specialty vehicles that don’t have suspensions.The comfort is quite good and better than inflated tyres” said Terry K. Gettys, Executive Vice-President, Research and Development, and member of the Group Executive Committee at French tire company Michelin.[4]

Military testing has indicated that the Tweel deflects mine blasts away from the vehicle better than standard tires and that the Tweel remains mobile even with several spokes damaged or missing.

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. As a demonstration of Tweel viability and reliability, three highway driven vehicles (a 2012 Honda CR-Z, a resto-modded 1955 Morris Minor Traveller, and an Aluma brand trailer hauling a Polaris ATV which was also equipped with Tweel tires) successfully participated in the entire 2013 Hot Rod Power Tour long distance road trip event in June 2013.[6]


The LRI AB Scarab Tweel

The iBOT mobility device and Segway‘s Concept Centaur were both introduced with Tweel airless tires. Michelin also has additional projects for the Tweel concept on small construction equipment, such as skid steer loaders, for which it seems well-suited.

NASA has contracted Michelin to develop a wheel for the next generation Lunar Rover based on the Tweel concept.[7] This has resulted in the Lunar Rover Initiative AB Scarab wheels.[8]

In October 2012, Michelin North America Inc. began commercial sales of the Michelin 12N16.5 X Tweel for skid-steer loaders used in landscaping, construction, contracting, refuse/recycling and agricultural industries.[9]


On 8 November 2005, Popular Science magazine named Michelin’s Tweel as the “Best of What’s New”[10] honor in the Automotive Technology category. The next day, Michelin NA was awarded a Hall of Fame Award by InnoVision[11] for continued leadership in innovation as evidenced by the development of the Tweel. TIME Magazine named the Tweel as “One of the Most Amazing Inventions of 2005”[12] a few short days later on 14 November 2005. The Intermat innovation commission in Paris (the International Exhibition of Equipment, Machinery and Techniques for the Construction and Building Materials Industry) awarded the Tweel with a 2006 Gold Medal for Innovation.[13] This prize reinforced Michelin’s technological leadership and rewarded Michelin’s contribution to improvements in productivity and safety for the construction industry. The jury of Intermat 2006 was made up of recognized European experts and professionals and required to rank the innovations according to five criteria:

  • Technical design and technologies: improvement in productivity, ease of maintenance;
  • Economy: lower purchase price and maintenance costs;
  • Quality of work carried out;
  • Ease of use, ergonomics, comfort, safety and improvement in working conditions;
  • Environmental friendliness.

A Silver Award in the Transportation category was awarded to the Tweel SSL on 26 April 2013 by the 2013 Edison Awards.[14] Of the 7,156 applications received, 131 finalists were selected by the Edison Awards Committee. The Tweel SSL was one of 42 winners, who represented 12 categories and symbolize the persistence and excellence personified by Thomas Alva Edison. The Tweel SSL was selected as one of the 2013 Contractors’ Top 50 New Products[15] by readers of Equipment Today as one of the industry’s most innovative products for the year. In January 2014, Equipment World named one of the “five game-changing” construction products of 2013 for their 2014 Innovations Awards. The Tweel SSL was named as one of those five product winners.[16]


  1. “How the 12N16.5 MICHELIN® X® Tweel® SSL Works”. Michelin. Retrieved 2014-02-09.
  2. Grabianowski, Ed (2007-05-10). “How the Tweel Airless Tire Works”. HowStuffWorks. Retrieved 2014-02-09.
  3. a b MAYERSOHN, NORMAN (2005-01-03). “Reinventing the Wheel (and the Tire, Too)”. The New York Times. Retrieved 2012-01-15.
  4. “In future, tyres will be connected to vehicle information system: Terry Gettys”. Retrieved 2015-11-09.
  5. Jaime Holguin (2005-01-27). “Airless Tires? Consider The Tweel”. CBS News. Retrieved 2014-02-10.
  6.  “Foothills British Car Club of South Carolina Newsletter” (PDF). July 2014. Retrieved 2017-01-18.
  7.  Mircea, Serafim (2009-02-16). “Nasa’s Rover Vehicle equipped with Michelin tires”. Inautonews. Retrieved 2014-02-10.
  8.  Wettergreen, David. “Scarab’s Wheels”. Lunar Rover Initiative. Carnegie Mellon University. Retrieved 2014-02-10.
  9.  “Michelin ‘Tweel’ for skid-steers launched”. Tire Business. 2012-10-29. Retrieved 2014-02-10.
  10.  “Michelin Tweel − The tire that never needs air”. Popular Science. US. 8 November 2005. Archived from the original on 9 March 2013.
  11.  “2005 Innovision Technology Award Winners Named” (PDF). ISS Corp. 2005-11-09. Archived from the original (PDF) on 2006-05-14.
  12.  “Tweel wins awards: But Michelin’s non-pneumatic tire/wheel a couple years from market availability”. Tire Business. 2006-05-06. Retrieved 2017-01-18.
  13.  Warner, John (29 April 2006). “Michelin TWEEL – Gold Medal for Innovation, Intermat 2006”. Swamp Fox. Archived from the original on 24 December 2013.
  14.  “2013 Edison Awards Winners”. 2016-12-02. Retrieved 2017-01-18.
  15.  “Construction-Trade-Magazine”. Retrieved 2017-01-18.
  16.  “2014 Innovations Winner: Michelin Tweel airless tire | Equipment World | Construction Equipment, News and Information | Heavy Construction Equipment”. Equipment World. 2014-01-06. Retrieved 2017-01-18.
Wire wheel Wire wheels, wire-spoked wheels, tension-spoked wheels, or "suspension" wheels are wheels whose rims connect to their hubs by wire spokes. Although these wires are generally stiffer than a typical wire rope, they function mechanically the same as tensioned flexible wires, keeping the rim true while supporting applied loads. The term suspension wheel should not be confused with vehicle suspension. Wire wheels are used on most bicycles and are still used on many motorcycles. They were invented by aeronautical engineer George Cayley in 1808. Although Cayley first proposed wire wheels, he did not apply for a patent. The first patent for wire wheels was issued to Theodore Jones of London, England on October 11, 1826. Eugène Meyer of Paris, France was the first person to receive, in 1869, a patent for wire wheels on bicycles. Bicycle wheels were not strong enough for cars until the development of tangentially spoked wheels. They rapidly became well established in the bicycle and motor ...
Artillery wheel The artillery wheel was developed for use on gun carriages when it was found that the lateral forces involved in horse artillery manoeuvres caused normally constructed cart wheels to collapse. Rather than having its spokes mortised into a wooden nave (hub), it has them fitted together (mitred) then bolted into a metal nave. Its tyre is shrunk onto the rim in the usual way but it is also bolted on for security. A normal wagon wheel is dished so that in its lowest part, the spokes are perpendicular to the ground thus supporting the weight (with the axle not truly horizontal but angled downward toward the outside about 5 degrees). This is not done with artillery wheels.    Artillery wheel Motor vehicles 1927 Ford T with artillery wheels When higher speeds and consequently higher lateral forces were attained with the introduction of motor vehicles, the artillery wheel was used in those too. By the 1920s, motor cars used wheels that looked at a glance...
Alloy wheel In the automotive industry, alloy wheels are wheels that are made from an alloy of aluminium or magnesium. Alloys are mixtures of a metal and other elements. They generally provide greater strength over pure metals, which are usually much softer and more ductile. Alloys of aluminium or magnesium are typically lighter for the same strength, provide better heat conduction, and often produce improved cosmetic appearance over steel wheels. Although steel, the most common material used in wheel production, is an alloy of iron and carbon, the term "alloy wheel" is usually reserved for wheels made from nonferrous alloys. The earliest light-alloy wheels were made of magnesium alloys. Although they lost favor on common vehicles, they remained popular through the 1960s, albeit in very limited numbers. In the mid-to-late 1960s, aluminum-casting refinements allowed the manufacture of safer wheels that were not as brittle. Until this time, most aluminum wheels suffered from low ductility, usuall...
Rim (wheel) The rim is the "outer edge of a wheel, holding the tire". It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube. The term rim is also used non-technically to refer to the entire wheel, or even to a tire. In the 1st millennium BC, an iron rim was introduced around the wooden wheels of chariots. Cross section of a bicycle rim wooden bicycle rim with tubular tyre Characteristics Scratched rim on two-piece wheel. Black residue remaining from where the tire was seated on the "safety profile" rim. Diameter (effective): distance between the bead seats (for the tire), as measured in the plane of the rim and through the axis of the hub which is or will be attached, or which is integral with the rim. Width (e...
Wheel A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel and flywheel. Common examples are found in transport applications. A wheel greatly reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity or by the application of another external force or torque. Using the wheel, Sumerians invented a contraption that spins clay as a potter shapes it into the desired object. Three wheels on an antique tricycle The earliest wheels were m...