Tire selection determines, in part, how well your earthmoving equipment can do its job. And with more applications switching to radials, the number of options you have to choose from has increased, making selection a bit more complicated.
"In the past, construction was largely a bias market," says Cara Junkins, Titan. "Over time, radials have become more readily available. They give the end user another option. But he needs to know what his specific operation is and what his risks are, then decide which will be the best tire."
Today's newer equipment is also typically larger and more powerful, yet runs on the same size tires. "As the equipment gets more powerful, you get closer to the limit of that tire," notes Steve White, Michelin. "Making the right choice is in some regards more difficult, because you have to take that important factor into consideration."
Selecting the right tire is also important if you intend to implement a retread program. "A tire's casing is approximately 75% of the tire construction weight," says Roger Best, senior field engineer, Off Road, U.S. and Canada Commercial Tire Sales Division, Bridgestone Americas Tire Operations. "Consider choosing major tire brands when purchasing new tires, because major manufacturers have invested heavily in research and development of premium casings, which are likely to be better candidates for retreading."
Equipment type and travel needs
To ensure you make the right tire choices, start by matching to the equipment type. Off-road tires are classified as "E" for earthmovers such as scrapers and articulated or rigid dump trucks; "L" for loaders and dozers; and "G" for graders.
"The forces and conditions in which each tire works are different," says White. "A loader tire will typically need more sidewall protection because of the areas in which it works. A transport tire may not have the same level of sidewall protection, but it's designed to take the stresses of the load at higher speeds. In the case of an articulated dump truck, the tires flex in different directions as it makes a turn.
"That's why it's important to have the proper tire for your application," he adds. "Each is designed for the forces it encounters."
Some manufacturers offer dual-marked tires, which are suitable for transport and loader applications. For example, an E-3/L-3 can be used on a loader or transport vehicle. "Don't try to crisscross tires unless it's dual marked," says Junkins. "If you have a loader, use an L tire; if you have an earthmover, use an E tire."
Earthmover tires also carry travel restrictions, so you will want to consider how far and how fast your equipment will be traveling. An "E" tire is designed to travel a maximum of 2.5 miles one way at a maximum speed of 30 mph; an "L" tire is designed for 250 ft. at 5 mph; and a "G" tire can travel unlimited working distances at 25 mph.
"A loader tire has a slower travel speed because loaders typically pick out of a pile and dump in a truck," says Junkins. "Because they travel at slower speeds, they can carry a heavier load. That's why it's important to match the tire to the vehicle. A loader tire's bead and carcass are designed to handle a heavier load, where an earthmover tire of the same size and ply rating won't carry the same amount of load unless it's dual marked."
If you travel further or faster than these parameters, you may want to consider a radial tire, which is more forgiving of the heat buildup created in these conditions. Radials are becoming more available and, in fact, they're all that Michelin manufactures. There are differences in the construction, and each offers advantages in certain applications.
"Investing in a radial tire in an application where sidewall cuts are the main reason for tire removal may not work," says Best. "Radial tires are more susceptible to sidewall cuts due to the flexing in the sidewall, where bias tires are very rigid in the sidewall. The radial tire has a very stiff tread due to the use of several steel belts within the construction design of the tire.