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The Inside Tread Tire Manufacturers Discuss How Off-Road Racing Spawns New Tire Durability Technologies By Dan Sanchez Everyone knows flat tires don’t win races, but over the five decades that racers have attempted to conquer Baja, tire technology has improved dramatically. Several tire manufacturers who have tested their products in Baja racing have seen the benefits of their efforts with new technologies and designs that are far superior to what has been manufactured in the past. Although today’s off-road enthusiast and racing tires seem almost indestructible, tire manufacturers are continuing to adapt to the changing vehicles. SCORE Trophy Truck and Class 1 buggies are dominant forces in off-road racing, but UTVs have also become a popular vehicle in this motorsports scene. For tire manufacturers, making a 40-inch Trophy Truck tire and a 32-inch UTV tire requires two completely different engineering teams and the help of many racers to design and manufacture a winning tire. Peter Calhoun, Motorsports Marketing Manager at BFGoodrich Tires, is one of the several tire industry insiders who gave us some insight into how they test in Baja and what some of the latest trends and technologies have come as a result, and what we can expect in the future. Cameron Parsons, Product Manager, Competition & Specialty Tires at Toyo Tire U.S.A. is another industry insider we spoke to, along with Fardad Niknam, Yokohama Tire Sr. Director of Product Planning and Marketing, and Mark Thornburg, President of Moto Race Tire. Score Journal: What kinds of tire innovations have been developed over the years from the company’s involvement in off-road racing? Peter Calhoun, BFGoodrich Tires: Racing is often used for research and development, as it is a dynamic real-life laboratory, where we can develop and test new construction techniques, materials, or processes. The best example goes back to our earliest days in off-road when BFGoodrich introduced the Radial All-Terrain T/A® in the mid-1970s. As America’s first manufacturer of radial tires, BFGoodrich was on the cutting edge of technology, but the radial tire had not yet gained the acceptance in the light-truck market that it had in passenger cars.  More recently both the All-Terrain T/A KO®2 and Mud-Terrain T/A KM3® included racing in Baja as part of their development process to test performance and durability on a variety of terrain. The “Baja Champion” inscription engraved into each sidewall of those models, is not a marketing slogan. It is battle proven and earned on the famed peninsula by winning a class at a SCORE sanctioned race. Cameron Parsons, Toyo Tires: We’ve made many positive developments over the years, contributing mostly to improved wear characteristics and drivability. Desert racing utilizes some of the harshest and most complicated racing surfaces in motorsports, pushing the tires’ limits in durability as well as handling performance. Toyo Tires has evolved its Open Country M/T-R desert race tires with compound, construction, and tread pattern changes that each lends to better wear life to increase the distance between needed pit stops while improving damage resistance from rocks and debris. Our latest, 2019 Baja 1000 winning, iteration came in the form of a 40” diameter tire, furthering the tire’s ability to withstand the desert’s punishing conditions and the race vehicles’ extremely high demands. Fardad Niknam, Yokohama Tires: Yokohama’s involvement in off-road motorsports has had a tremendous impact on our consumer tires, especially in the areas of compounding and carcass construction. Although it wasn’t a direct replacement, the GEO-SHIELD 3-ply casing used on our GEOLANDAR X-MT, GEOLANDAR M/T G003, and GEOLANDAR X-AT was a direct result of our development of the GEOLANDAR MT-R, the tire we currently use with off-road drivers Justin Lofton, Levi Shirley, and many others. Also, trying to find the correct balance of durability and traction for the MT-R helped tremendously in developing the compounds for the GEOLANDAR X-MT and GEOLANDAR M/T G003. We developed a new tire construction using Kevlar, high strength nylon, and high strength polyester. We use up to six layers for total tire construction that increases strength and puncture resistance throughout the tire. This construction also allows running flat for up to 50 miles. We also came up with what we call Dual Durometer. We use different rubber durometers in the lug than we use on the tire sidewall. We usually make the sidewall a harder rubber (higher duro), and the lug and softer duro (lower number). Our Apex Bead is a polymer insert layered from the bead wrap up the sidewall. This eliminates what’s called “Bead Pinch” where the tire pinches with the rim and causes puncture. SJ: Was there ever an “ah-ha” moment from a particular race or experience with a team the company had been working with? Calhoun: Not necessarily an ah-ha moment but one of BFGoodrich’s greatest strengths being part of Groupe Michelin is the vast array of motorsport disciplines we compete in globally, but also the vast experience we can draw on from our other consumer and business units. From circuit racing at the highest levels of sports car racing to MotoGP, aircraft to mining, agriculture to trucking, we can develop unique product solutions in motorsport using this experience that no other competitor in the world can pull from within a single organization. Parsons: We’ve experienced a few of these moments that have lent to our secret sauce in our latest 40” Open Country M/T-R. Through close communications with our racers and studying a whole lot of data, we’ve discovered some key elements that have helped us improve upon our race tires and to help the teams better set up their vehicles to complement these tires. Thornburg: We teamed up with Phil Cagliero in 2017 who won the Ultra 4 series and the Ultra 4 West. He used the same set of tires for all of the races with zero flats. At the start of the 2018 season, he didn’t want to take them off. I told Phil I wanted to show them at races, he agreed to change, and thankfully he won the next race or I was in the dog house. He did not want to take the tires off! He won on one set of tires.  SJ: What makes a full racing tire different from an off-road enthusiast tire? Calhoun: When we look at the sport of desert racing and race tires versus light-truck recreational tires, the most immediate difference is the Department of Transportation (DOT) compliance which is required for tires to be operated on public roadways in the U.S.A. and Canada. Tires are one of the most highly regulated components on a vehicle and all those markings on the sidewall are not there for aesthetics. They all tell a story to the trained eye, the most obvious its size, but also load capacities, speed ratings, maximum pressures, where and when it is was manufactured, and much more. So it is both performance and safety-related. For non-DOT race tires, or in BFG slang “red labels”, these are pure race tires not intended for highway use. They are purpose-designed and built for one intention to win races. This allows some freedom and a more open playbook for the designers and engineers to extract maximum performance. Where street-legality or civility is not required, nor is a tire that lasts 50k miles. Parsons: A full race tire often uses a different compound and/or construction from an enthusiast tire. That being said, the Open Country M/T-R desert racing tire is very similar to our Open Country M/T, which is available to enthusiasts everywhere. The racing tire is built with extra reinforcements to make it more durable and puncture-resistant, to better last in the environment that it’s intended for. With this extra reinforcement and protection comes extra weight, which is why the race tire is intended for racing vehicles only. The Open Country M/T carries over the off-road performance characteristics of the race tire while offering more road-oriented features for enthusiasts. Niknam: The racing tire needs to stand up to completely different stresses than a replacement consumer product. Motorsports products need to withstand much higher horsepower and torque which are rarely found in consumer trucks. The high-speed and brutal terrain found in Baja racing is unlike anything a consumer will experience in their personal vehicle. Racers will use the tire to its max in a very limited time so the tire is developed to optimize for those conditions. On the other side, we need to consider tread wear, road noise, and style when developing a consumer tire to make everyday drivability and value a priority. Thornburg: Our MRT XROX DD truck tire works for both, Race and drive home on the same set. We use a stickier compound so wear is in the 30K range. Off-road tires have stronger sidewall construction and a stickier rubber compound. We combined and used special carbons to increase wear with the stickier compound. SJ: Racers often give feedback, but what type of info are engineers looking for (ie. temperatures, visual cues, feel, etc.), and how does that translate to making changes in the tire? Calhoun: Our engineers love to talk about tires. No other tire company I know of is as engaged with the community to give and receive feedback as BFGoodrich or Michelin, and this does not matter where we compete. There never can be too much information to put into their data-bank to continually improve our product and services based on real-life experience in competition. From a performance standpoint, it all starts with pressures and temperatures, and tire engineers talk about “hot” pressures. That is the target hot operating pressure to maximize the performance of your race vehicle. This will take into account parameters such as vehicle weight, tire model & size, ambient temperatures, racecourse conditions, etc. There is no cut and paste answer to what the right pressure is for your application, but that is where our engineers on-site can be of great assistance and are a great added value to using BFGoodrich tires along with our award-winning pit support program. Parsons: We look for as much information as possible! More details provide our engineers and R&D team with the big picture, helping us understand every element that contributes to a tire’s performance. We pull data from the vehicles, considering everything such as g forces, driver inputs, suspension activity, and of course tire data. As useful as onboard data is, it only tells a part of the story. Feedback from the drivers and co-drivers, tire temperatures, inflation pressures, and a visual inspection of the tires help fill in the remaining details. There are situations where gathering data in only one or a couple of these areas won’t tell you enough, or might even lead you to the wrong conclusion, so it is always important to collect as much information as you can. Niknam: We have worked with several racers and our engineers collect everything from driving feedback, temperature, hardness change, and appearance. We frequently take the tires back after races and run endurance and/or C-Twist tests to measure heel and tow wear on tire tread. We also optimized the tread pattern by hand-cutting tires during the race sessions to find the best tread for a particular condition. Thornburg: We are looking for levels of traction, tire flex, stiffness, and separate PSI. We’re also looking at how well the tread cleans and always want to know load, temperature, PSI, under various driving conditions and terrain. SJ: We’ve seen tire diameters increase, why does this change, and is there a point where diameters can be too large? Calhoun: In the simplest of terms bigger tires, smaller holes. And yes there can be a point of diminishing return for as when the tire grows larger in diameter, it most often gains weight. Some race cars simply do not have the power or suspension travel to maximize its use and with the additional rotational mass can also put a strain on driveline parts such as CV’s and wheel bearings. In some classes regulations also come into play on the wheel and tire size to maintain a desired performance or cost level, not everyone drives a Trophy Truck. Parsons: The increase in tire diameters comes with a few benefits. A larger tire suffers less rolling interference when it comes to obstacles and debris. It also offers higher ground clearance, helping save equipment in severe off-road conditions. A larger tire also means greater internal air volume, increasing its load-carrying capacity over smaller tires, which is becoming very important in regards to how heavy and powerful modern race trucks have become. One of the main trade-offs, however, is unsprung mass and spinning inertia. For many enthusiast vehicles, some large diameter tires may be too heavy and cause extra stress on the drivetrain and suspension components. Niknam: While the trend has been a steady increase in diameters, it is doubtful this will increase beyond 40-inches given the current equipment. Racers like larger diameter tires as they provide more clearance and better overall balance. However, there is a tipping point at which tires will not be balanced as the diameter increases. That said, drivers are still winning with 39-inch tires in the unlimited classes.  Thornburg: In the UTV segment, tire diameters increase to add clearance for rocks, whoops sections, and sand. Increased rim sizes can help with using larger brake calipers for improved stopping. The point the tire is too heavy for the vehicles would be the limits.  SJ: Are tires made differently now than they were several decades ago with modern tools, CAD, and other methods that can improve their design? Calhoun: The design and engineering process may have changed with modern tools, but the actual manufacturing process of a radial tire is very much as it has been for decades since its introduction by Michelin. You still have over 200 unique components that go into every single tire, but each has its unique recipe depending on its intended use.  There are very few components on a modern vehicle that takes as long to design and develop as a radial tire and when you are looking at original equipment (OE) tires in partnership with the manufacturers they are highly tuned to meet their performance targets for ride comfort, handling, braking, rolling resistance, and noise to name a few. Parsons: Tire technology is always improving, especially in compound developments and construction capabilities. The common thought in regards to compounds is that traction and wear rates are a trade-off; you can’t gain one without suffering losses in the other. Thanks to discoveries and developments that happen in the background, we’re able to close in on getting the best of both. And thanks to our ATOM (Advanced Tire Operation Module) manufacturing process, Toyo Tires can build tires with extreme precision to consistently achieve near-perfect roundness and uniformity. Still, we aim to always learn and find ways to make further improvements. This comes through strenuous testing from the lab to real-world applications, ensuring that we are always trying new things and analyzing what benefits are to be found. Niknam: Tire technology has leaped forward in the areas of compounding, construction, and building techniques. A few generations ago, mud terrain tires were little more than small agriculture tires. Yokohama’s GEOLANDAR M/T’s and GEOLANDAR X-AT’s durability and traction make those old tires look prehistoric by comparison. Thornburg: Yes, the ply on a tire used to mean how many belts it had. Eight-ply had eight belts. The Radial tire changed construction allowing different materials to be used in the belting process increasing strength with fewer belts.  SJ: With modern tires, it would seem there’s little room for improvement. Are there certain areas that can still be designed to provide better traction, handling, etc? Calhoun: There is always room for improvement, but of course improvement means different things to different users. Some want wear, some want grip, some want ride comfort, some want noise. A trademark of BFGoodrich and Michelin tires has always been the well-rounded performance we offer in our consumer tire models, but this is also an area where race tires can differ significantly and take performance to the extreme. We’ll get racer input for more grip or improved wear, but ride comfort and noise are not things we hear often from our racing customers. The other consideration is that as cars evolve, tires evolve, or in some cases the other way around to complete the package. In 2014 when the Baja KR2 was introduced it added improved grip under acceleration, corner turn-in, and braking versus the old warhorse Baja KR; and then the engine builders could throw more power at the truck. So now in 2020, it is not unheard of to hear of 1000+ crank horsepower Trophy Trucks when maybe 5-6 years ago 750-800 was a more common number. Putting that amount of horsepower to the ground would not have happened with the tires of 10+ years ago. Parsons: While most tires follow a similar formula in their design and construction, there is a surprising level of detail where you can still make significant changes. A lot of it comes down to materials and construction techniques, which are constantly being improved upon. Take a look at tires in almost any category ten years ago compared to today, they might look the same but their performance is drastically different. Niknam: There is still room for improvement in all areas of tire development: compound, construction, and manufacturing. Small improvements in all these areas can add up to a more useable and valuable tire. As vehicle and driver needs evolve, Yokohama will continue to press development to meet those needs and push tire technology forward. Thornburg: Yes, we are always looking for new advantages to make a stronger lighter grippier tire. One of MRT’s largest expense is in R&D. Continuous improvement. Innovation is the key to our success. MRT is not like other tires.   SJ: UTVs are becoming one of the most popular vehicles for off-road racing and recreation. What are some of the advancements being made to improve tires for these vehicles? Calhoun: UTV’s are a perfect example of where a high quality, high performing tire can completely change the user experience. UTV’s as off-road recreational vehicles are not being regulated to the extent of automobiles or light-trucks, and are most often being delivered with underwhelming tires. When upgraded to include a true performance wheel and tire package, with a desert racing provenance, such as the BFGoodrich Baja T/A KR2 or Mud-Terrain KM3, this can transform the vehicle’s performance and ultimately the enjoyment of the owner. The KR2 and KM3 are both recipients of our decades of learnings in off-road racing and are designed and engineered in the USA specifically for UTV’s; they are not a light-truck tire repurposed. Parsons: UTVs and side-by-sides are booming in popularity, and as a result, they are also becoming much more diverse in their usage and capabilities. Now, each of the major side-by-side manufacturers offers upgraded trims of their vehicle models, packed with powerful motors and advanced handling components and design. This means consumers are exploring rougher and overall more demanding uses for their side-by-sides. This is why Toyo Tires jumped straight to offering a 32x9.50R15LT tire specific for side-by-side applications as the company’s introduction to this segment. This Open Country SxS tire carries over design and construction similarities from the Open Country M/T-R desert racing tire, to better complement high-performance side-by-side vehicles on rough trails or in off-road racing environments. Niknam: Developing a radial tire that works on UTVs in real life is still in the early stages. The balance between durability, weight, and traction performance still needs work. We are working with the best UTV team to bring a radial tire that works for UTVs. The Yokohama Super Digger III bias tire is currently leading in the areas of balanced performance and weight. Thornburg: All the above is used in our UTV tires. MRT has the strongest, lightest UTV tire in the industry. We spent a lot of time and resources testing the latest innovations in the UTV arena. SJ

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