The pneumatic tire over 150 years ago by Robert Thompson. As it turns out, “a rubber doughnut filled with air” was only one of several tire ideas he was working on.It seemed like a great idea at the time, but he wasn’t sure that it was possible to keep the air contained within the tire.Other designs he had involved filling his proposed tire with resilient substances such as sponges, hayand even horsehair. Those seemed to be a better idea because substances like that don’t leak out easily! The object of all of this, of course, was to have a tire that absorbed road shocks and thus provided a comfortable ride for the riders in the carriage (Remember: this was before automobiles). So, even though the pneumatic tire had yet to be perfected, research 150 years ago was being put into tires that weren’t inflated by air!
Airless tires on the Moon
Fast forward to the space age. Despite over 100 years of success with pneumatic tires on automobiles, the concept of an airless tire appeared once again. This time, however, it was for use on the Moon.The reason for this is pretty simple. Astronauts on the Moon can’t risk a flat tire! So, in the 1970s, NASA’s Lunar Rover was outfitted with four 9-by-32-inch tires consisting of steel-mesh wheels – no air involved.
Back on Earth, the Tweel was developed
Perhaps gaining some momentum from the Lunar Rover design, the concept of an airless tire became a serious concept once again back here on Earth. While many companies were working on the airless tire concept, some were coming up with workable models. Our consultant on this article, Atlantic Lexus of East Farmingdale, NY, informed us of Michelin’s work in this area. In 2005,Michelin designed the “Tweel,” a thin rubber tread band supported by dozens of V-shaped polyurethane spokes. Introductory performance claims versus conventional pneumatic radials were actually impressive. Studies showed that they were capable of two to three times the tread life of conventional tires and five-times-better lateral stiffness.
Airless tires are still years away
Despite plenty of R&D and many players working on the concept, non-pneumatic tires are realistically a decade away. Beyond their performance, two things will propel them toward acceptance: Tire companies must address the recycling of such tires and, of course, expense. The new wheels must not only perform as well or better than pneumatic tires, they must be cost competitive with the old technology. After all, over 100 years of pneumatic tire use has resulted in a product that may not be perfect, butis consistent and affordable.