Tweel
| Industry | Tire manufacturing |
|---|---|
| Headquarters | Clermont-Ferrand , France |
| Products | Tires, including the Tweel airless tire |
The Tweel—a blend of the words tire and wheel—is an airless tire innovation created by the French tire manufacturer Michelin. Unlike traditional pneumatic tires, the Tweel operates without compressed air, thereby eliminating risks such as punctures, leaks, or blowouts. Its design incorporates flexible polyurethane spokes that connect the central hub to the rim, absorbing impacts that would normally be cushioned by air pressure.
Design
The Tweel consists of a standard rubber tread paired with a shear beam situated beneath it, which forms a compliant contact patch. It also includes energy-dissipating polyurethane spokes and an integrated inner hub. Both the shear beam and the spokes can be tailored for directional stiffness to enhance handling characteristics and load-bearing capabilities. The inner hub may be constructed as either rigid or compliant, featuring deformable plastic components that flex under load and revert to their original shape. By modifying spoke dimensions, designers can fine-tune ride comfort and handling performance. Additionally, the tread is replaceable and customizable in a manner similar to conventional tires.
Benefits and drawbacks
Among its primary advantages are the elimination of flat tires and potential improvements in braking effectiveness due to independently optimized lateral and vertical stiffness—unlike pneumatic tires where these properties are interdependent. The absence of an air bladder allows for tread designs with water evacuation holes, which help reduce hydroplaning. Michelin estimates that the tread lifespan is two to three times longer than that of standard tires. The ability to replace the tread also contributes positively to environmental sustainability by minimizing waste.
The Tweel is particularly well-suited for vehicles lacking suspension systems, such as lawn mowers and other low-speed specialized equipment, delivering enhanced comfort compared to inflated tires, according to Terry K. Gettys, Michelin’s Executive Vice President of research and development.
Military evaluations have demonstrated that the Tweel offers superior blast deflection from mines compared to conventional tires and remains functional even when some spokes sustain damage.
Initial automotive prototypes encountered challenges including noise generation, vibrations at high speeds, and approximately 5% greater rolling resistance than radial tires; however, these issues were addressed by 2013. Highlighting its durability, three vehicles equipped with Tweels successfully completed the 2013 Hot Rod Power Tour without any problems.
Applications
The iBOT mobility device and Segway's Concept Centaur were both introduced featuring Tweel airless tires. Michelin is also advancing the Tweel for use in compact construction machinery such as skid-steer loaders, where it provides distinct benefits.
NASA commissioned Michelin to develop a Tweel-based wheel for future lunar rovers, resulting in the Lunar Rover Initiative AB Scarab wheels.
In October 2012, Michelin North America launched commercial sales of the Michelin 12N16.5 X Tweel designed for skid-steer loaders, targeting industries including landscaping, construction, contracting, waste management/recycling, and agriculture.
Awards
On 8 November 2005, Popular Science honored Michelin's Tweel with its "Best of What's New" award in Automotive Technology. The following day, Michelin North America received a Hall of Fame Award from InnoVision recognizing innovation leadership exemplified by the Tweel. TIME Magazine also included it among "One of the Most Amazing Inventions of 2005."
At Intermat 2006 held in Paris, the Tweel was awarded a Gold Medal for Innovation in acknowledgment of its contributions to safety and productivity within construction. The jury assessed entries based on criteria such as design quality, economic impact, ergonomics, safety enhancements, and environmental considerations.
The Tweel SSL earned a Silver Award in Transportation at the 2013 Edison Awards, selected from over 7,000 submissions as one of 42 winners symbolizing outstanding innovation.
In 2013 as well, readers of Equipment Today voted the Tweel SSL into the Contractors’ Top 50 New Products list for its industry innovation. Subsequently, in January 2014, Equipment World recognized it as one of five “game-changing” products within construction during its Innovations Awards.
Inventors Timothy B. Rhyne and Steven M. Cron were jointly awarded the prestigious Charles Goodyear Medal for their pivotal role in advancing tire technology through the development of the Tweel.
Uptis
In 2020, Michelin collaborated with GM to create the Unique Puncture-proof Tire System (Uptis), which is expected to be available on select GM vehicles starting in 2024. This innovative tire was first showcased at the Internationale Automobil-Ausstellung (IAA) mobility exhibition in Germany, fitted on an electric Mini Cooper.
GM initiated trials of Uptis on a series of 2019 Chevrolet Bolt electric cars and aims to introduce it as an optional feature on certain models by 2024.
The Uptis design incorporates an aluminum wheel structure combined with rubber strengthened by glass composite and vinyl ester resin, resulting in improved toughness compared to previous models such as the Tweel.