Tires represent a significant portion of equipment spending after operator and fuel costs. When considering whether to retain the standard tire as approved by the original equipment manufacturer, or to request a different model from the same line, or even to move to an aftermarket option, contractors need to consider whether the tire is designed specifically for the application (i.e., for the environment in which the equipment will be running). For example, a tire operating on rough terrain may need a deeper tread than one traveling primarily on asphalt. The goal is to reduce the per-hour operating costs; a tire that is designed for the application will last longer and be more environmentally sound, cost-effective and safe.

The upfront costs of radial and bias tires can be very different. Radial price tags can run as much as twice those of bias ply, but in the right setting, can last two to three times longer. 

Radial vs. Bias Ply
At the most basic level, a tire is a compact unit—consisting of rubber compounds and steel and textile reinforcing materials—that has to fulfill several basic functions, including safety, load carrying capacity, dimensional stability, traction force transfer, adhesion, shock absorbing capacity, weather resistance, and puncture and cut resistance.

While all tires are designed to meet those basic functions, differences exist. Today’s fleets are fairly evenly split between bias-ply tires and radials, both of which have associated benefits and impacts on operating costs.

Radial tires are the preferred modern design, providing better traction, a larger contact area and higher driving comfort due to sidewall flexibility. From cars and big earthmovers to tractors and motorcycles, most of the new equipment on the market today is equipped with radial tires. 

Bias-ply tires are an older design. The contact area of bias-ply tires is smaller, and the driving properties are affected by the rigid sidewall. The tires’ footprints vary, so contact with the surface is limited when changing driving direction or loads. On the technical side, bias-ply tires have a multi-wire bead design and generally are heavier.

A radial tire allows the sidewall and tread to function as two independent features of the tire. A bias tire has multiple rubber plies overlapping each other, and the crown and sidewalls are interdependent and act as one component. The radial tire has a flexible sidewall that provides benefits in that they are generally stronger than the comparable bias ply tire, and can envelop an object versus allowing it to penetrate and damage the tire. Also, radial tires are more easily repaired after they are damaged.

The diagonal ply construction of bias ply tires provides more rigid sidewalls, which are beneficial for uses where stability is extremely important. Bias ply tires are also generally less expensive. Radial tires typically run cooler, have a wider, longer and more stable footprint, leading to a longer tread life.

The Tech Inside the Tire
The premium tire industry has developed a range of innovative ways of looking past the tread, which is the most visible aspect of tire health, and into the tire’s inner workings. From “connected” tires that transmit tire health data (e.g., internal temperature, which has a huge impact on tire lifespan) to a fleet management system, there is a wide range of advanced designs that allow the product to increase productivity and improve safety while reducing a fleet’s environmental impact.

Because tires are critical to operation performance, construction executives should take the long view when making purchasing decisions. Rather than focusing on the price tag, consider the factors that contribute to the total cost of ownership: application, innovation and functionality. 


Jimmy McDonnell is director of OEM sales for the Trelleborg Wheel Systems industrial and construction tires operation in North America. For more information, contact Trelleborg here.