Bridgestone's North Star: Developing airless truck/bus tire

When it comes to nonpneumatic tire development, Bridgestone Americas Inc. likes to think it is aiming for the stars—a "North Star," more precisely.

Because when it comes to the company's proprietary Air Free tire development, the Nashville, Tenn.-based tire maker isn't so much concerned about the micromobility, OTR or passenger vehicles spaces just yet.

Birdgestone, instead, is thinking bigger.

Like, 50,000 pounds big.

Yes, the tire maker is targeting the commercial truck tire market with its Air Free tire development, and it's starting with trailer tires.

"We started off at the very beginning (with), don't short-putt," Jon Kimpel Bridgestone Americas' vice president of extended mobility solutions said during a May 31 conversation that was part of the tire maker's Thrive podcast series. "Meaning, don't go and go along with what is easy. Go with what there is an adjustable market for."

That decision may, on the surface, seem counterintuitive, even if it is the space where Bridgestone's airless tire technology could have the biggest impact. The commercial truck segment seems like a space you work up to, testing technologies and ideas at smaller loads—smaller applications—before taking that insight and applying it to trucks.

But the Bridgestone approach, though extremely challenging, makes sense, Brandon Nelson, Bridgestone Americas' manager of advanced extended mobility technology, said on the podcast.

"That trailer tire really being our North Star, really got us to aim higher," Nelson said. "We can scale that technology down. But it is really hard, when you have a solution that is set for something like a lower energy density, to scale that up and be successful."

The Bridgestone team knows that, because it's tried.

The tire maker's journey into the airless tire realm began with the rollout of an Air Free bike tire in 2013.

Four years later, Bridgestone purchased Resilient Technologies and its airless tire technology designed for off-road applications. And while that technology works—and works well in that space—it wasn't something that the Bridgestone team could easily and successfully scale up.

So the team rethought its approach and decided to aim high—at the space where the nonpneumatic tire technology is most needed.

"We decided that, today, the biggest need is more in the fleet market, the trucking market," Kimpel told Rubber News. "Especially in the trailer position, which tends to be a lower maintained wheel position, especially when it comes to air pressure.

"So we have been focusing a lot more of our efforts on the trucking industry, but with the sight that we can go and take that and apply that modeling and design and materials science to other applications in the future, like autonomous vehicles."

Tackling the truck tire space is one thing.

Doing it with an airless tire is something else.

"One of the things we don't realize about air tires—pneumatic tires—is that air does 80 percent of the work in carrying the load," Nelson said. "And it is very efficient, it's free, and it's lightweight—there are all these benefits to it. And so, when you take that out of the tire itself, you have to replace that with something. And so the materials are now doing the work."

That makes the structure of the nonpneumatic tire the single most important piece to puzzle out. Because that structure has to support a lot of weight, manage any hazard the road has to throw at it and be both lightweight and sustainable.

And all of that makes its design—and especially its materials—critical.

"First is getting to that stage of an efficient assembly that works," Kimpel said. "But then, longer term, how do we get to that and make sure the materials are recyclable?"

That is where Kimpel believes Bridgestone has an advantage, given the scope of the products it makes.

"You can categorize Bridgestone just as much as a material science company as it is a tire company," Kimpel said.

So the nonpneumatic tire team is expanding beyond its tire expertise in its search for the best materials. And it's an approach that Kimpel has encouraged, asking the team to seek the expertise of material scientists in aerospace and other industries.

"We have a lot of really strong, really great materials out there to choose from. But they are not that strong yet," Nelson said. "We are at a unique moment in time where the materials and the technology are starting to come together to make this possible, but it's still at the cutting edge, it's the tip of the spear. So it's very challenging to make it all work together."

Kimpel contends there are several factors that have bolstered Bridgestone's bold approach, but one is making the greatest difference: advancements in tire modeling. The technology, he said, has allowed the Bridgestone team to test thousands of ideas without missing a beat or losing valuable time and resources.

Nelson agrees. The ability to test ideas and prototypes through extremely accurate and reliable simulation has progressed the nonpneumatic tire development significantly, he said. And that ability also completely changed the team's approach.

"We are changing how we design. We are being more meticulous with how we design," Nelson said. "We are using our virtual tools in a way that we have never used before, and we are creating stronger technology every day."

So what, exactly, goes into the modeling that Bridgestone is leaning into? Well, just about everything.

"We're talking all of the elements in a tire, plus the full suspension on a truck, plus hitting objects on the roadway," Nelson said. "It is a large model, but one that the team has been able to develop in way that it runs quickly, it gives us reliable results, and coupling that with Amazon (Web Services), we are able to run thousands of iterations in weeks. And that is game-changing.

"Because before (that) we were running, you know, an iteration here and we're thinking about it, (and then running) an iteration there. And we would never have found the solution because you are just wandering in the dark so to speak.

"And now, we have the ability to map the whole space and we can say, 'Oh. That's where we need to be.' "

For Bridgestone, the significance of the modeling means it is not just changing the game for its Air Free tire development. It's changing the game for all of its tire development. Because some of the insights gleaned from the nonpneumatic tire simulations can apply across sectors.

"We have gone from a tire (iteration) that had a rolling resistance of 30—and if you are familiar with tires at all, that is unheard of," Nelson said. "The tire would actually light on fire at that point, riding down the road. … Now we are at—potentially—industry-leading rolling resistance, even among pneumatic tires. So that's a feat. That's impressive."