Your Guide to Understanding Tire Science

Tires are often overlooked, but they are essential to the successful operation of many construction vehicles. They are incredibly sophisticated, highly engineered products that derive much of their performance power from two elements: compounding and tread design.

Compounding

Seemingly generic and nondescript rubber compounds are the building blocks of better tire performance. In simple terms, compounds consist of various formulary ingredients that can be tweaked to generate specific performance benefits, depending on a tire’s intended application, the surface it is designed to travel across and other factors. Up to 4 to 6 compounds can be found in the crown area of a standard construction tire, starting at the tread and extending all the way down to the tire carcass. It is paramount that attention is paid to how different compounds interact with one another while the tire is in operation. 

Because construction vehicles roll over challenging surfaces that are often strewn with rocks and other potentially tire-penetrating debris, construction tires should be tough and cut-resistant to help counter the tremendous amount of scrubbing that can be caused by near-constant contact with ultra-abrasive surfaces. To achieve these properties, some tire manufacturers add a higher percentage of carbon black filler, which offers reinforcement and gives tires their trademark hue. Tires that contain compounds with more carbon black filler in them are typically more abrasion- and cut-resistant.

Tread Design

Construction vehicles often travel across a variety of surfaces, from loose gravel and slippery mud to dry, tightly packed dirt. This can all happen in the same shift, which makes traction a critical performance benefit. In construction applications, one way to boost traction is by using a tire with a deeper, “more luggy” tread pattern. Tire suppliers sometimes use the term “net to gross” to describe this concept. Tires with higher net to gross generally feature more open tread patterns for enhanced traction. Tires with lower net to gross swing the other way; they have less open tread patterns that often offer lower levels of traction. 

The level of tread depth and traction required can be influenced by the type of machine and the anticipated underfoot condition—or, in other words, the composition of the material underneath your tires. For example, an articulated dump truck that operates on softer surfaces typically will require a tire with less tread depth. However, a tire that boasts deeper tread depth might be more appropriate for a vehicle that rolls across more severe surfaces. When in doubt about tread depth, tread patterns or tread compounds, always consult an authorized commercial tire dealer. A knowledgeable dealer can help you evaluate your equipment’s needs and underfoot conditions and make appropriate recommendations for each piece of equipment. 

When evaluating your equipment needs, don’t overlook the tire’s sidewall, which plays a major role in equipment stability. As a general rule of thumb, the stiffer the sidewall, the more stability a tire provides. Tire manufacturers sometimes stiffen a tire’s sidewall by increasing its thickness, tweaking its compound and/or adding reinforcements. In addition, make sure that tires are not mismatched around the vehicle. For optimal performance, stick with identical diameters, tread patterns, tread depth and tire construction (radial or bias), regardless of axle. This simple but effective practice can help reduce the incidence and rate of tire wear. 

Using tires that feature the right compounds and tread design is just one part of the performance equation. Tires that have been placed into service need to be systematically maintained. Inspect your tires’ inflation levels at least once a day, or even better, before each shift. Avoid both under- and over-inflation, since both conditions can impair tire performance. Also, check tires for outward signs of developing problems, including nicks and cuts. A qualified tire professional can help you address these issues. By keeping the above principles in mind, you can help optimize your tire investment, and in turn, the efficiency of your overall operation.