Direction Matters When Mounting Tires For Sonoma Is Concerned
Sonoma Raceway poses several challenges for NASCAR Sprint Cup teams, and at least one of those challenges has been taken up by The Goodyear Tire & Rubber Company.
At Sonoma, Goodyear uses one of its “softest” tread compounds to give the cars as much grip as possible. Add to that – as with the series’ other road course at Watkins Glen International – Sonoma puts an increased stress on the front tires with heavy braking into the turns and an increased stress on the rear tires with harsh acceleration off the corners. Those factors combine to put undue stress on a part of the tread that is most susceptible – the tread splice, or the area that is joined together in the manufacturing process.
Because of all that, Goodyear will mount its D-4678 tires (same on all four corners of the car) for Sonoma in a directional manner, helping to insure that the tread splice is “closed” under both braking and acceleration.
“The tread compound used at Sonoma is one of the most tractive used for all Sprint Cup Series events,” said Greg Stucker, Goodyear’s director of racing. “As such, we utilize some special techniques to prep the tires for the race. This includes the orientation in which tires are mounted.
“At most events, tires are mounted as either a left side tire or a right-side tire. Teams can freely interchange fronts and rears on the same side of the car. For Sonoma, we will employ directional mounting, where the left-front and right-rear are mounted the same, and the right-front and left-rear are mounted the same. This directional mounting helps to protect the beveled splice of the tread component, insuring the splice is closed under the force of braking on both front tires, and closed under the force of acceleration on both rears.”
While helping the competition on the track, this mounting procedure will provide a slightly different look for team tire specialists as they arrange their five sets of practice/qualifying tires and five sets of race tires throughout the weekend.
“The right-front tire and the left-rear tire will be mounted with the ‘non-serial’ side facing outwards,” explained Stucker. “The molded information for press position and date code on these tires will be on the inside of the assembly rather than the outside. During mounting, the tires will be marked with the positions in which they are allowed to be run – right-front/left-rear or left-front/right-rear. This will allow both tires on the front axle to have tread splices that close under braking and both tires on the rear axle to have tread splices that close under acceleration.”
To go along with all that, Goodyear’s distinctive yellow lettering will be applied to both sidewalls of each tire. That way, no matter which side of the car a particular tire is mounted, the “Goodyear” and “Eagle” branding will be visible.
Stucker also points out that although this mounting orientation is unique to Sonoma for the Sprint Cup Series, it is a technique that’s used extensively by Goodyear in other forms of road racing.
Road course racing is somewhat out of the “norm” for NASCAR teams. Drivers are asked to turn both left and right, there are more turns with varying degrees of radii, there are more radical elevation changes than on an oval, etc. Sometimes special problems require special solutions. As always, Goodyear is up to the challenge.