Goodyear Finalizes Eldora Dirt Tire

For Goodyear, the challenge of building tires for NASCAR is a diverse undertaking. Making safe and competitive tires as the exclusive supplier for NASCAR’s top three national series means developing tires for race tracks ranging from one-half mile to 2.66 miles long, on concrete and asphalt, and surfaces as rough as a cheese grater and as smooth as glass.

This season, with the NASCAR Camping World Truck Series adding the dirt track of Eldora Speedway to the schedule, the challenge got even bigger. The inaugural “Mudsummer Classic,” scheduled for Wednesday, July 24 at the half-mile track in Western Ohio, will be the first NASCAR national series race held on dirt in more than 40 years.

But for Goodyear, who has been involved in a wide array of racing disciplines over the years, it was just a matter of dipping into the playbook and coming up with a solution.

“Although this is the Camping World Trucks’ first race on dirt, Goodyear has produced dirt tires throughout its racing history,” said Greg Stucker, Goodyear’s director of race tires. “We are very familiar with dirt, and we are very familiar with Eldora.”

The new “Wrangler” tires that Goodyear will bring to Eldora for the Truck Series are based upon a dirt modified tire in its tire line. However, the NASCAR dirt tire has been widened to 11 inches (from 10 inches) to provide a larger contact patch with the track and give the trucks more grip. The two primary differences from the standard race tires run on ovals in NASCAR’s top three series is that the Eldora tire will (1) be a bias ply tire and (2) feature a tread pattern.

The bias ply tire construction is not as stiff as the radial tire used on paved NASCAR ovals, therefore it is more compliant and more able to envelope the irregularities of a dirt surface.

As far as the tread, the Eldora tire features Goodyear’s G23 pattern, which is a standard block pattern. It has grooves and biting edges to help evacuate dirt from underneath the tire, giving the trucks more grip. The tread compound itself is on the “softer” end of the spectrum, which will also help with grip.

While the Eldora right-side tire will basically remain the same height as a NASCAR tire run on asphalt tracks (circumference of 88.5 inches / 2,248 mm), the left-side is a little shorter (circumference of 85.8 inches / 2,179 mm) to build in more stagger, which will help the trucks turn better.

For Goodyear, the tire development process started last October with a test on the 10-inch tire at Eldora with track owner and three-time Sprint Cup Series champion Tony Stewart, former Camping World Truck Series champion Austin Dillon, and his brother and current Truck Series contender Ty Dillon. In addition to seeing how the tread pattern evacuated the dirt and the compound put down rubber, it was important that there were no clearance issues which could lead to the tires rubbing against the truck or its suspension parts.

“Overall, everything on that first test went well, considering that was the first time for the trucks on dirt,” said Stucker. “We felt, however, that it would be beneficial to give them a little more tread width, and we already had the capability to make a wider tire.”

Once Goodyear produced the 11-inch tire, Ty Dillon went back to 311 Speedway, a dirt track in Pine Hall, NC.  When everything checked out with that test, Goodyear had its Eldora tire.

“The Trucks racing at Eldora is a historic event for NASCAR,” said Stucker. “Building off our long history of making both dirt tires and NASCAR tires, this process has been both fun and challenging. The Eldora truck race will be a highlight of the 2013 NASCAR season, and Goodyear is proud to be a part of it.”