INSIGHT: Where the rubber meets Next Gen's road

Motorsport Images

INSIGHT: Where the rubber meets Next Gen's road

Insights & Analysis

INSIGHT: Where the rubber meets Next Gen's road


Let’s start by making sure we have the right vernacular down. When NASCAR Cup Series teams start competing with the Next Gen vehicle next season, said vehicle will feature a wider tire. Wider. Not necessarily bigger, and it isn’t much taller than the tire teams have used for decades.

“It is considerably wider, about an inch and a half,” Goodyear director of racing Greg Stucker explained to RACER. “You’re running on a wider wheel. That’s where the dimensions change pretty dramatically, and obviously, we go from a 15-inch to 18-inch wheel diameter.

“That’s a significant change when you’re controlling the outside diameter; not making the tire any taller, but you’re making the hole in the middle bigger because the sidewall shrinks. So, the challenge on a big heavy race car like a Cup car is to try to absorb the load and deflection that we experience now on a short sidewall.”

NASCAR announced plans to go to a seventh-generation car in 2019, and the industry has been climbing a mountain of work since. For Goodyear, things fully ramped up once NASCAR and the OEMs had settled on the wheel diameter that they wanted to work with.

It was an easy decision. Stucker noted there are not many 15-inch wheel diameters in the marketplace, so making a change was natural. While the OEMs then went to work on making their body designs more relevant to what is on the street, Goodyear did the same from a tire and wheel perspective.

How wide could they go? How tall could it be? Goodyear worked to answer those questions as Next Gen’s suspension geometry and other technical aspects came to life. Except there was one difference in the work done by the tire company versus others. Goodyear’s engineers were the only ones who could say they had experience with some aspect of the new car.

“We’ve made 18-inch race tires forever for sports car racing,” said Stucker. “It wasn’t new to us. It’s new to this application, without a doubt. This is the first time that anyone, any tire company, will be running 18-inch in an oval application like this where the loads are so high, speeds and everything are sustained like they are on an oval. So, we took our experience from the 15-inch and 18-inch, we know the envelop we had to stay in, and we got to work.”

There isn’t a performance crossover of the 18-inch tire from sports cars to NASCAR, so that wasn’t where Goodyear worked. Instead, they were leaning more on previous experience of what they needed to do from a manufacturing and design perspective.

“The first thing we did was start running through our durability numbers,” said Stucker. “We got a lot of feedback from the OEMs, from the design team from NASCAR, to understand what the car is going to be like, what the load is going to be like. The car was supposed to be lighter, but it needed up being about the same, so it didn’t get the diet that it was supposed to.

“From that perspective, the loads will be pretty similar to what we have today, and so we had a good starting point with regard to our durability tests. Obviously, we make sure we have a robust tire that will handle the loads and the speeds and everything of the vehicle. Once we were satisfied with that, then we started getting ready for the on-track testing. That’s where you learn the most.”

The Next Gen will feature a single lug nut on the wheel, which won’t impact the incoming wider tire delivered by Goodyear for next season. John K Harrelson/Motorsport Images

A Next Gen prototype first got on track at Richmond in October of ’19. By November of 2020, the car had completed five different tests, and Goodyear was there every step of the way. Dates designated specifically for tire testing have picked up over the last year, such as most recently when Goodyear worked with Tony Stewart at Bowman Gray Stadium to confirm the tire for the L.A. Coliseum race in February.

Making sure nothing strange crops us is the main agenda of tire testing. For a car with a different suspension, aerodynamics, and undertray, Goodyear first wanted to make sure it was in the ballpark with what it thought would translate when arriving at the racetrack.

“Truly, every time we’ve gone to the racetrack, it’s fallen in place,” Stucker said. “I would say that’s a testament to not only the homework we’ve done, but NASCAR did with the race car. Probably the most significant thing is that the car will let us go with a little bit softer compound. It just seems to be the progression we’re learning as we go from racetrack to racetrack.”

There are two footnotes in the Goodyear Next Gen tire building process. First, they too were given more time to prepare when the project was delayed until 2022 because of the COVID-19 pandemic. However, it had nothing to do with the tire design, and everything to do with ramping up manufacturing.

“We know how to make 18-inch tires, and we have the equipment to make a certain number of 18-inch tires, but we didn’t have the equipment to make the number of tires needed,” Stucker said. “Just the volume of tires we use… there is no other series that has that many. Yeah, ramping up and making sure we had enough equipment and building machines, the conveyor belts to move product. Just a lot of changes that had to be made through the manufacturing facility to get us up and running, and that gave us the time to get that done.”

And second is that single, center-locking lug nut that is so polarizing.

“It doesn’t really change anything for us,” said Stucker. “The wheel dimension didn’t change other than the center lug. So, from a tire design perspective, it doesn’t make any difference to us. There is not a change for us.”

Next Gen makes its points-paying debut in three months and four days at the Daytona 500. But its first competitive race will be an exhibition event earlier that month at the LA Coliseum. Right now, Goodyear is confident it has a solid platform, but with organizational tests coming, including this week at Charlotte, that wider tire will continue to go through the paces.

“We just get a lot more feedback because now you’ve got more drivers at the same time on the track, and it’s their cars,” said Stucker. “We all know once the teams get something and start working on it, things evolve. We’ll start to get a lot, a lot of feedback so that we can make sure that we’re ready for the start of the season.”

MX-5 Cup | Round 1 – Daytona | Livestream