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From Concept To Trail: Tire Basics

Chevy Truck Blasting Through Mud
Ken Brubaker
| Senior Editor, Four Wheeler
Posted April 1, 2012

Tire 101

Tires are a lot like shoes. Any shoe will protect your foot but there are specific shoes for specific activities. What works well in one activity may not work so well in another. For example, a basketball shoe works really well on the court, but not so hot on a hiking trail. A hiking shoe works great in the trail environment, but doesn’t cut it on the court. Similarly, the same is true for tires. Any tire will allow your 4x4 to roll, but there are specific tires for specific types of terrain and there are compromises with each. Here’s the thing: Shoes are relatively inexpensive so it’s feasible to have several different types on hand to match whatever activity presents itself. Tires, on the other hand, are not inexpensive. This means you have to get it right the first time. To do that, you need to purchase tires that help maximize your rigs performance in the type of terrain you most often travel. The best way to do that is to understand basic tire construction and the basic features of a specific class of tire.

The Basics
There’s a lot that goes into a tire before it actually goes into production. Cooper Tire, maker of the familiar Discoverer tire, follows this procedure: 1.) Marketing concept development. 2.) Product development. 3.) Mold development and procurement. 4.) Prototype procurement. 5.) Prototype testing. 6.) Design certification. 7.) Manufacturing.

We’d love to show you the step-by-step process of how a tire is assembled, but almost every tire manufacturer restricts access to the actual tire construction process. This is because the tire business is very competitive and many of the processes and machines are proprietary. Basically, most radial tires consist of the inner liner, beads, body plies, antichafing strips, steel belts, tread, and sidewall. Most tire companies have technical centers where the staff can consist of mechanical and chemical engineers, chemists, physicists, and engineers. Among other things, these facilities are often where testing of the raw tire materials take place. During a tour of the Cooper Tire Technical Center in Findlay, Ohio, we saw its 7,500-square-foot materials laboratory where some of the machinery included a unit that is used to test rubber pellets. It could heat them, freeze them, and squash them to determine durability. Cooper has the ability to design, test, and evaluate tires on a computer. Of course, real world testing is mandatory, and for that Cooper has a sprawling 1,000-acre test center in Pearsall, Texas, which is home to a variety of asphalt tracks as well as numerous off-road courses. Point is, there’s a lot of technology and testing that goes into a tire before it gets the green light for mass production.

Quite simply, in the 4x4 world you can break tire styles down into three major classes: all-season, all-terrain, and mud-terrain. Each of those classes contains a significant number of variations. The all-season class offers tires that specialize in snow and ice, for example. The all-terrain class is loaded with different tread designs of varying aggressiveness. Similarly, the mud-terrain class includes everything from somewhat mild tread designs to wildly aggressive purpose-built tires.

It’s no secret that the average 4x4 spends the majority of its time on the pavement. This means that quiet operation and wet weather and snow performance rank high on the list of desirable features for these tires. Typically they have a mild tread pattern with small voids between the tread blocks to decrease noise and improve steering response. These tires will also have lots of siping to funnel water out of the tread blocks and offer increased grip on ice. Internal construction often varies by size and load rating. The downside to these tires is that the mild tread pattern means they slip more than they grab onto typical trail obstacles like rocks and dirt; most sidewalls aren’t designed for off-road travel so they’re susceptible to punctures; the soft tread can chunk in rocky terrain; and because they aren’t designed for it, they tend to load up in the mud. On-road, they’re the king, offering near-silent noise emissions, incredibly grippy performance, a smooth ride, low rolling resistance (which will help your vehicle’s fuel efficiency), and long wear characteristics. Off-road their construction helps to contribute to a smooth ride and they typically perform well in sand and snow when aired down.

Some of the tires in the all-season category include:
BFGoodrich Radial Long Trail Tour T/A
Cooper Discoverer H/T
Falken Landair H/T
General Grabber HTS
Goodyear Wrangler ST
Nitto Dura Grappler
Yokohama Geolandar H/T-S

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