DANVILLE, Va. – Harnessing the power of the latest computer modeling and testing technologies and a new tire production process, Goodyear has come to market with a long-haul steer tire it feels confident will raise the industry bar on performance for this most challenging of tire positions.

The G395 LHS steer tire for over-the-road fleets and owner/operators is a tire that is new from the ground up.

It includes an “evolving” five-rib tread design with a barrel footprint that Goodyear says optimizes treadwear performance. And it’s also designed to be a “tire within a tire,” which, according to Goodyear, will result in performance through each stage of wear.

“As the original tread wears down, jagged/angled groove walls across the footprint are exposed to maximize traction and handling and give better bite,” explains Ted Fick, vice-president of Goodyear’s commercial tire division.

The G395 also includes a pressure distribution design that boosts tire life. Located at the outer edge of the shoulder rib, the pressure distribution groove has a larger radius, which reduces pressure build-up. When cornering, the reduced pressure improves shoulder wear and helps eliminate the risk of irregular wear and cupping,” says Joe Zekoski, director of commercial tire technology.

Increased tire life

“Ultimately, this increases the life of the tire,” he adds.

Another key design feature is the lateral sipes and slots on the three main ribs for traction and handling.

“Traction is maintained throughout the life of the tire,” claims Zekoski, explaining that in the worn condition, the angled rib walls begin to perform, which provides better traction over the life of the tire and allows the tire to run longer in the challenging steer position.

All five ribs include edge blades, which play an important role in treadwear performance. The edge blades provide resistance to propagation of river wear, which would otherwise lead to lower miles to removal.

And the new tire also uses Goodyear’s ECD (Enhanced Casing Design) puncture-resistant, four-belt package with high-tensile steel on the three lower belts. The top belt is made with polyamide, which protects the steel belt package from moisture.

Goodyear went high-tech in developing the G395, employing specialized computer programs during several steps in the design process, including using proprietary software that was developed jointly with the federally funded Sandia National Laboratories in Albuquerque, NM.

In the beginning, when several design options were on the table, Goodyear designers logged thousands of hours performing computer modeling, a capability enhanced by the Sandia relationship. During this phase, Goodyear used both commercial and in-house computer programs to perform its Finite Element Analysis (FEA). The proprietary software enabled Goodyear to build and run powerful FEA computer models that churned important data in hours rather than days or weeks, as was the case in the past.

“We simulated a wide variety of tread designs, tire mold shapes, construction configurations and material combinations,” says Tim Richards, Goodyear’s leader for the engineering team responsible for developing the new steer tire.

During the second phase of development, Goodyear engineers were able to perform extensive tests of various tread designs and belt configurations on experimental versions of the G395 LHS. One test measured footprint pressure and shape, which provided insight into the tire’s treadwear characteristics. Another test, called the Frictional Energy Analysis, used a high-speed video camera to monitor a tire rolling over a glass plate to analyze tread slip in the footprint. Still another test in the Goodyear lab measured accelerated tire wear by running tires through an aggressive, simulated treadwear route that provided wear results in a matter of weeks versus traditional testing that requires many months on the road.

Laser mapping

And in the final phase of development, Goodyear challenged its experimental tires in road tests at its proving grounds in San Angelo, Texas, and in focus testing by commercial fleets. In the San Angelo test, a laser mapped tires in great detail at regular intervals to track the evolving wear patterns. This laser mapping was further analyzed by Goodyear’s treadwear analysis software. Using data display software, Goodyear was able to analyze the 250,000-treadwear measurements on each test tire, compared with five measurements obtained manually by a technician under previous testing.

Goodyear also used its new Integrated Manufacturing Precision Assembly Cellular Technology (IMPACT) in manufacturing the G395 LHS. The process, which Goodyear is attempting to patent, is claimed to be so precise the tires coming off the assembly line are “virtual clones” of each other. More than five years in development, IMPACT integrates component formation and assembly, automated tire assembly and curing within a cellular system.

IMPACT minimizes the opportunities for error in tire building, Fick explains.

“There are 50 per cent fewer process steps and much of the labor involved in the tire build has been replaced by computer control. These controls provide us with a distinct advantage in the manufacturing process. It ensures that our tires are industry leading in uniformity,” Fick says.