Critical Choices: Tire and Track Selection

July 20, 2015

A piece of equipment is only as good as its tires or tracks; those elements determine how efficiently and economically a piece of equipment will work. They are a true productivity issue and can cost 10–20% of the total job cost. Improperly sized tracks can result in shortened service life. Outfitted with inadequate tires or tracks, the machine won’t perform to its full potential; worse yet, in some circumstances, it could be damaged by the wrong tires or tracks.

The universal message from tire and track manufacturers when it comes to selection is: know the application. The application determines the grade of tire—or track—needed, says Steve DePriest, sales product trainer with Hyundai Americas. But, as Mike Dembe, market development manager for construction North America Camoplast Solideal, points out, there are a lot of variables.

“Some styles of tires and tracks work better in certain applications than others,” explains George Valev, Director of Original Equipment Manufacturer (OEM) Accounts for McLaren Industries Inc. Steel tracks are ideal for the most aggressive terrain, while rubber tracks work well for most other jobs. When it comes to tires, pneumatic tires are most commonly used. However, if the job site is littered with debris, then solid rubber, foam-filled, or semi-pneumatic tires are better options.

While users have different criteria, tires are very important in the grand scheme, declares Aaron Murphy, vice president of Double Coin Tire. They deliver traction and mobility at a cost per hour. Unfortunately, purchase price too often becomes the main deciding factor in buying tires and tracks, rather than more important factors such overall performance, which leads to lower lifetime operating cost and application.

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While the “big guys” who work on a site for months, doing one job repeatedly, can afford to specialize in a specific type of tire or track, most contractors opt for the versatility of a multipurpose selection that will allow them to run under all conditions at multiple job sites. “Smaller contractors can’t afford to let equipment sit,” says Jim Enyart, technical service manager for BKT USA. For them more than the rest, selection depends on what the machine will be used for. “The choice is usually application-driven. Will you be working on flat ground or an incline? Will you be pushing dirt or smoothing it?”

Credit: Alliance Tire Group
Tread patterns characteristics

Deal With It
In addition to understanding the equipment and the application, Dembe says it’s a good idea to communicate conditions and issues to the dealer. “Have a conversation with the dealer; he will lead you and help you make an informed decision.”

The dealer plays a big role, Murphy concurs. Because dealers work with multiple end-user companies, they can share knowledge about warranties, support, OE cooperation, and end-user feedback about tire performance. “The dealer can be big influence.”

When selecting tires, go to a tire professional and ask for help in understanding the application and critical criteria, advises Bruce Besancon, vice president of marketing for Alliance Tire Americas Inc. “Contractors are good at their job, but they are not experts at tire selection.” One consideration he mentions is whether the machine is working daily or is a backup machine.

Because many equipment dealers don’t specialize in tires and tracks, Camoplast Solideal emphasizes dealer training, teaching them what questions to ask, educating them about the products and solutions and encouraging them to make a site visit so they become more knowledgeable. “They need to know about surface conditions, what the customer is doing with the machine, the type of loads—dense sand, wood chips, or something else…” Dembe elaborates.

Sometimes it’s best simply to go with the tires a machine comes with, and change to another type when it’s time to replace them. However, if you spec them the way you want from the start, Dembe points out that the cost of upgrading tires can often be rolled into the financing costs.

Tracking Decisions
“If you make a poor choice in tires, it could be disastrous,” states Besancon.

Disastrous and costly. “Everyone wants to run the Cadillac of equipment, but it must make business sense,” says Enyart, explaining that the decision is partly application and partly budget.

Dembe says tires and rubber tracks can be the most expensive consumable items on the equipment. “They are used in demanding applications and contractors go through them frequently. They’re expensive—and you have to multiply the cost times four (or two for tracks). Pay attention to what you’re using and what your options are, and you’ll minimize this cost.”

Select a product with the quality and performance you expect. Consider the warranty, who stands behind it with service and support and weigh the cost per hour versus the lowest purchase price.

Look at all the options to understand which offers the best operational cost. Murphy points out that the purchaser is not always the operator, and that the operator may know the conditions better, so it may be wise to include him in the decision.

Decisions are often stacked, one contingent upon another. The first is tire or track. “A tire is a 30-minute change by a trained professional,” estimates Besancon. “Track is difficult.” Downtime is minimized with tires; it takes longer to fix track than a tire.

“There are trade-offs with tracks,” adds Enyart. Tracks can last a long time, depending on whether they’re rubber or steel, but there is more long-term maintenance required. “There are a lot of rollers and bearing and bushings—lots of pieces and parts of the operating system that require greasing—a lot of moving parts.” The drive and pulleys are an issue.

“The driving mechanism is what fails over time.”

Maintenance costs are higher for track because it has more pieces and a more complicated drive chain. “Track is more maintenance; tire is air pressure only,” Besancon sums up. Operating costs may be higher as well, particularly in the area of fuel consumption. “Tracks carry more weight, so they burn more fuel.”

Machines equipped with steel track can’t be run on hard surfaces, so site location must be taken into consideration during the selection process. When working in unimproved or wet areas, machines need traction and protection. Motorgraders doing finish work require stability to keep the blade even. Conversely, rubber track is best on improved ground. Additionally, DePriest says steel track is used on most “midsize and up” equipment.

Although in general, track is more robust than tires and can go through rebar and metal, ground pressure is an issue. Wide track works best on soft ground, and narrow track works best on hard ground. Wide tracks on medium ground can bind the gears, sprockets and undercarriage if you run over rock. The pivot point on wide track gets more torque, which can cause it to bend. Narrow track has less tendency to bend. To determine what the situation calls for, DePriest instructs contractors to “figure out the total weight of the machine, divided by how much track touches the ground.”

Besancon provides a list of decision factors:

  • Mobility—do you have to travel 100 yards or 5 miles?
  • Speed
  • Will equipment be trailered or driven to the site?

Decisions That Tire You Out
Opting for tires brings no fewer decisions. Perhaps the easiest way out is to run the tires the equipment came with. Most OEMs put “a large volume of equipment on a multipurpose tire, not an application-specific tire,” observes Murphy. An all-purpose general tire does the job in multiple applications. Most contractors don’t swap out tires, DePriest observes. “They leave them on the machine until they’re worn out; that’s why they choose middle-grade tire.”

Tires should provide traction, protection and mobility, says Besancon. He recommends the Alliance 550 as a good multipurpose four-season tire that provides light traction, a good ride, and biting edges in snow.

To determine whether a multipurpose tire is good enough or a specialty tire is required, similar decision factors for track selection apply, with a few additions:

  • Type of vehicle
  • Distance traveled
  • Speed
  • Load type and weight
  • Ground surface characteristics

Speed will determine tread depth. An “L” tire’s maximum speed is 5 miles per hour, a “G” tire’s maximum speed is 25 miles per hour, and an “E” tire’s maximum speed is 30 miles per hour. Load will determine pressure requirements, ply, and star rating. Ground surface characteristics will determine tread pattern and traction requirements.

Once out in the field, the contractor may want to make some tire changes, unless he’s able to afford separate equipment for multiple applications. If a contractor is considering a different tire, he should look at the application and usage. Tire choice will reflect the environment, not the type of equipment, explains Murphy. For example, when working in sandy soil in Florida, cut and chip resistance is not as important as traction. But doing road work in Colorado’s rocky soil requires a different type of tire to do the same job.

Tread Lightly
Soil conditions can also dictate tread patterns. Although Murphy says he hasn’t seen a lot of change in tread patterns because “what the equipment is doing hasn’t changed much,” Besancon says changing the tread pattern, size, and compounds are the only things manufacturers can do; everything else is up to the operator.

Tread patterns are determined by application, states Murphy. Most common is a “multipurpose tread,” but for severe environments, a deeper, more durable tread is needed.

“There are different tread patterns for different applications,” confirms DePriest. “Most tires have a standard tread similar to a Michelin pattern—a middle-of-the-road tread pattern. If you need more grip, you’ll want a different style of tread.”

Traditional tread patterns offer a certain amount of versatility and can usually handle rain and snow, but they don’t accommodate mud, says Enyart. Working in mud requires traction, which calls for a directional pattern and lug style. “For loose or wet soil, you need an open pattern. A more open tread clears mud better. If the voids between the lugs fill with mud, you’ve got a slick.”

This kind of pattern, typical on L-4 and L-5 tires, wears faster and holds heat. It’s why articulated dumps don’t drive on the road. “There are always trade-offs,” notes Enyart.

Tread patterns vary widely, depending on the application. If all a large company does is road building, Enyart says by way of an example, county and state road graders will choose a specific tread pattern designed for efficiency, consistency, and adequate traction for local soils. Mini excavators are generally outfitted with a diamond pattern with rounded tread that is easy on turf.

On softer soil or around office buildings or in a residential setting, more stability is needed, indicates Murphy. That means a different tread pattern. “A grader only grades one way, so you need optional traction to go one way. A loader needs traction for forward and backward; dump trucks also need traction in both directions.”

A directional lug design provides “biting traction” in the travel direction, and good steering.

A block pattern benefits on hard surfaces. Block-type tires are puncture-resistant and resist wear from concrete or asphalt that would grind lugs or bars into nubbins. But unless they’re designed for good self-cleaning, they will quickly turn into racing slicks in the mud.

Mud calls for lugs or self-cleaning bars. A line of blocks down the centerline provides stability and durability on hard surfaces. Overlapping bar treads or block-type tires with a line of big blocks in the center deliver similar benefits, and improve ride smoothness.

“High under tread” refers to a large mass of rubber beneath the tread blocks—a puncture resistance feature. This is not a good choice for transport driving at road speeds because heat builds up. Heat kills tires.

Alliance’s basic 550, designed with sweeping lugs broken up into blocks, provides more edges for traction in snow. The blocks are closer together than a standard, ag-style lug tire, which provides a smoother ride and puts more rubber in contact with the ground—the rubber-to-void ratio. A high rubber-to-void ratio provides a large footprint, smooth ride, high tread wear life, and minimum surface damage. The large footprint is good for flotation and can help with traction, especially in snow or loose ground.

The Solideal SKS 775 for skid-steer loaders works on hard surfaces and for severe duty applications such as road building, waste recycling, and demolition. “It has a massive 50/32nds tread depth,” says Dembe, “and a high lug-to-void ratio.” Incorporating hauler steps to clear out mud, it won’t bog down. The innovative tread pattern is combined with a sidewall impact guard for added protection.

Another new offering for skid-steers from Solideal is the SKS 732, a premium off-road tire with massive tread depth for durability, long life, and traction. Its curved and tapered tread lug design enhances traction, and even wearing. “It has wrap-around hauler steps—a mud cleanout device,” explains Dembe. “Clean tread means higher traction.”

It also features an innovative and radical side wall design. The impact guard, or “reverse sidewall,” creates a wedge to deflect material and reduce cracking. “It protects from flat tires due to sidewall impact,” says Dembe. Sidewall construction is important for machines that operate on slopes, grades, or piles of dirt because it provides stability. The trade-off, however, can be heat building and a stiff ride.

A rib or street-type pattern provides a smoother ride with more mobility, suitable for finish grading, explains Besancon. The number of grooves provides efficient self-cleaning of soil.

Radial Versus Bias
When it comes to traction, radials provide more of it than bias tires. They also provide better flotation, ride, wear over a lifetime and comfort, lists Enyart. Grading is more accurate. Bias tires run on higher air pressure, making the machine bounce, diminishing accuracy and operator comfort. “Radials have less slip, which affects productivity.” Bias tires spin, causing the operator to lose time and be less productive. It also increases tread wear.

An L-3 radial is spec’ed the most, says DePriest. “It’s standard on wheel loaders for road and building applications. An L-3 bias is cost-efficient, but has more bounce. “The radial has more support; less bounce under load. If you’re not using a machine on roads, you may not care, but if the bias sits for a long time, it gets a lump when cold.”

Hyundai carries five brands of tires, allowing the customer to choose. But, says DePriest, the cost difference is a factor in the decision. “Radials are expensive.”

The price difference between bias and radials is not as big now, says Enyart, explaining that while the upfront cost remains higher, the long-term operating cost is lower.

“People want [radials] so they’ve become cheaper to produce,” explains Murphy, who adds that “some manufacturers don’t even make bias anymore. Bias tires are for a specific need. Why buy high-end radials?”

He lists some of the benefits of radial tires:

  • They run much cooler, enabling them to run more hours
  • They are more forgiving when they run over obstacles
  • They provide better traction
  • They provide better fuel economy
  • The contribute to increased vehicle steadiness
  • They exhibit superior cut resistance

As a rule of thumb, radials provide better traction, cut resistance for tread, heat resistance, flotation, and fuel economy. They generally wear better. Bias tires offer vehicle stability and cut resistance for sidewalls. They are self-cleaning and repairable. They are also typically less expensive.

Types of Tires
Double Coin provides some basic explanations for the different types of tires and their potential uses. An E-1 rib design tire is typically used on free-rolling axles. E-1 tires are used on steering axles of dump vehicles or material handling equipment. Designed with a one-to-one lug-to-void ratio that provides good traction in sand and soft soil materials, E-2 tires are most commonly used on self-loading scrapers. E-3 tires have a two-to-one lug-to-void ratio, providing resistance to rock damage and good traction. They are primarily used on end dumps, bottom dumps, articulated dumps, and scrapers. These tires offer good heat resistance for use in operations where long-haul distances and high speeds are encountered. The shallow rib tread of the E-7 lends itself to equipment that runs in soft, sandy soil. It is also often used on asphalt spreader vehicles.

L tires for OTR loader and dozer applications feature heavy construction that limits them to slow speeds and short haul distances: up to 5 miles per hour for 250 feet. L tires are also used in load and carry applications: up to 15 miles per hour for distances up to 2,000 feet.

L-2 tires provide maximum traction in sand and soft soil conditions, as well as tread-cleaning benefits. The L-3 rock design adds rock resistance to traction for loader operations. The L-4 rock design has a heavy tread mass for more rock resistance and tread life over the L-3. The L-5 rock design is the most popular type of loader tire because of its extremely heavy tread mass for even greater rock resistance and extended tread life in severe rock conditions. For the ultimate in resisting rock damage and penetration, the L-5S solid features massive tread and smooth design to eliminate shoulder lug tearing in severe rock loader applications.

“Solid tires are an increasing trend,” indicates Dembe. Based on end-user input and extensive development that includes benchmark testing and real-world field testing, Camoplast Solideal recently introduced a solid tire for skid-steer loaders: the SKS 793S. Its non-directional tread pattern is great for mixed applications. The reusable wheel translates to a lower cost per hour, while its elongated aperture design reduces cracking and its tread depth increases service life over previous versions.

Alliance also has a new line for skid-steers: the Beefy Baby Solid. Besancon explains that it is best for “very heavy duty applications like recycling, demo and rebuilding in urban areas or harsh environments with a lot of concrete, and rebar, where its solid and deep tread offer more protection.”

Even if a job site is not filled with debris, Valev says “semi-pneumatic tires are an ideal solution because of their deep treads that provide for better traction and longer wear factor than standard pneumatic tires.” Although there are some exceptions, he says, many tires and tracks perform well across a variety of applications.

No matter what the application, downtime is a concern for contractors. McLaren Industries has developed a series of technologies to extend service life. For instance, the NuAir semi-pneumatic tires are designed to provide thousands of hours of service life with no downtime. Rubber tracks feature SpoolRite belting technology, which uses a single, jointless, non-overlapping, continuous steel belt with exclusive lug designs to maximize durability and extend undercarriage life.

The Cost of Choices
Extending the life of a tire has financial benefits. Cost of ownership is an important consideration in the choice of tire. For example, says Valev, semi-pneumatic tires cost more than pneumatic tires, but they have a lifespan that is at least three times longer. In addition, semi-pneumatic tires virtually eliminate costly downtime due to a flat tire.

“It’s easy to go with the cheapest product, but that’s a short-term solution,” Enyart cautions. He advises taking a long-term view instead. With increasing optimism about the economy, he sees more contractors willing to invest in tires, not just buy tires. Still, they watch their budgets carefully. While Murphy acknowledges that there is no typical company, he says many bigger companies are willing to take a risk on a new product in order to drive down the budget.

Several things affect the cost of a tire. The initial cost of a radial tire is higher than that of a bias tire, but the cost per hour depends on many factors, including maintenance, the operator and the application. “Tire life depends on how it’s used,” states DePriest.

Spec correctly for the job to make tires last longer. “If a machine is for X weight, but the contractor wants more and uses counterweights on back or fills the tires with water, the machine wears faster because it’s overworked,” DePriest elaborates. It’s an old trick. Some fill the tires 90% full with a water-saline solution or water-antifreeze mix to give them extra weight when they have heavy bucket loads or are pushing heavy material. Similarly, some contractors let the air out to get better surface contact on soft ground. Extended practice can cause premature wearing.

Tires are most often replaced due to punctures, but if they sit, unused, a long time, they become dry and can rot or crack. It can happen, especially to big contractors who keep machines on different tires for specific types of jobs.

Driving style, application, and job site are tough on tires. New equipment takes all of them into account, says Besancon. “As technology evolves, it helps reduce wheel slip and increase productivity.” Even technology like laser siting can be an advantage: when it takes less work to get results, there is less wear and tear on the tires.

Sometimes contractors who have experience with certain products don’t want to change. “They don’t want to try something new,” observes Murphy. It can be difficult for new manufacturers to convince them to try new products.

One way to convince reluctant customers is to manufacture better quality tires from natural rubber compounds instead of synthetics, Dembe believes. “It provides better performance. It’s cut- and chunk-resistant.” It’s part of Camoplast Solideal’s engineer and design philosophy, he says. “We’re vertically integrated: we own and control production, from tree to tread.”

Sell It Again, Sam
No matter how well-constructed a tire is, one day it will wear out. “Nobody wants to buy a machine with worn-out tires,” reflects Enyart.

Dembe concurs that it’s “tougher to sell at auction if there’s an obvious need for new tires or tracks.”

Tires play an important role in resale, Besancon believes. “Prospective customers ask: How many hours are on the engine? How much tread is on the tires? Ritchie Brothers include the percentage of tire on the machine in their ads.”

Murphy believes the amount of tread left on a tire is not as important as condition and brand. “An operator may over-use the tire, spin it, put the blade down too much or do other things that cause premature wear.”

While Enyart agrees that the operator makes all the difference in the world on the condition of the tires, he thinks most contractors don’t worry about resale. “They buy a machine to keep them in business and worry about resale later.”

Unfortunately, he says, because the construction industry has not good in recent years, many contractors are making purchase decisions based on short-term costs. “If the tires are cheap and can be run a couple years, many choose the cheaper option.” Although he thinks the economy is recovering, he believes people in the industry are cautious. “It’s hard to invest in a future with so much uncertainty. That’s why there’s so much downsizing—and so much equipment available.”