How Tractor Tires Hookup 

An ag tire’s ability to deliver traction has a large influence on its performance—whether it’s helping pull a field cultivator through tight soils or putting a big tractor’s 500-hp to the ground, a tire’s ability to deliver traction is of the utmost importance to farmers. Because of this, manufacturers spend millions of dollars to engineer tires that can generate forces in the field and on the road without slipping. No single part of a tire is responsible for delivering traction; rather, it’s a combination of parts working together to deliver maximum performance. 

degenhardt deerePhoto courtesy of Degenhardt Tire 

Why Traction Matters to Farmers 

A tire providing the ideal amount of traction can increase productivity, improve efficiency, and reduce the fuel consumption of farm equipment. It can also stop slipping and sliding, which tears up fields and negatively impacts yield and costs farmers money. After all, a top-of-the-line tractor isn’t particularly helpful if it gets stuck in the field and a 500-hp tractor is under-performing if it’s only putting 400 horsepower to the ground. 

Factors Affecting an Ag Tire’s Traction 

Tread and Lugs: The tread pattern and lug depth play a major role in determining how much traction a tire delivers and makes matching a tire’s tread to the conditions facing it vital to the productivity of your equipment and health of your soil. For example:

  • R-1: A traditional R-1 bias-ply or radial tire is ideal for use in general farming applications in light soil, pulling implements at shallow depths, and providing good performance on the road. 
  • R-1W: With at least 20% deeper lugs, R-1W tires—like our new Agri Star II—are well-suited to operating in heavier, wetter soils.
  • R-2: Sometimes called rice/cane tires, R-2 tires such as the Agri Star 374 feature at least twice as much tread as an R-1 tire and are best used in extremely wet and muddy conditions.
  • R-5: R-5 is a designation we give our technical treads like the Alliance 550 MultiUse and 363 AgriFlex+—these hybrid designs combine wear-resistant features of industrial tires with high-traction farm tire features to deliver game-changing performance. For example, our 550s are a favorite of farmers working the steep slopes found in eastern Washington fields. 

Tread Angle: The angle at which the lugs are positioned will affect the performance of a farm tire—often having a tire with the correct tread angle is as important as having one with the proper tread depth.  A good rule of thumb is that lower-angle treads are a good choice for working in drier soils, and higher-angle treads are ideal for work in wet conditions or on steep terrain like hillsides. In some cases, such as our new Agri Star II, a tire will have multiple lug angles, allowing it to excel in a variety of conditions over its life.


Lug-to-Void Ratio: When it comes to a tire’s traction, the space between a tire’s lugs is as important as the lugs themselves. This is because the “empty” space between the lugs allows tires to dig into a surface and shed mud, dirt, and water. In general, treads with lower lug-to-void ratios work better on soft surfaces (such as in the field). The space between lugs cleans dirt from the tread, so each rotation of the tire has a clean bite for traction. Conversely, tires with higher lug-to-void ratios work better on hard surfaces (like on the road).

Radial Construction: Radial tires put a broader, longer, flatter, and more evenly distributed footprint on the ground than a tire with bias construction, which tends to form a crown in the center of a tire. Radial construction maximizes the amount of tread on the ground and leads to superior traction—a radial tire’s footprint can be as much 25% larger than a bias tire. Another way in which radial construction leads to improved traction is that their sidewalls transfer engine torque to the tread, putting valuable horsepower where you want it: on the ground. 

Radial tires also provide a more comfortable ride than their bias counterparts—a huge benefit for operators spending long days in the field and on the road and reducing wear and tear on expensive farm equipment. 

Steel Belts: To produce maximum traction, a tire should apply its force evenly across its entire contact patch. Steel belts are beneficial because they help tires create the largest contact patch possible while also distributing a machine’s weight uniformly across them and helping the tread maintain shape under load. Because of this, all of Alliance’s AgriFlex IF/VF tires—along with a host of other Alliance offerings—feature steel belts.

Tie Bars: Anchoring the tread to the tire are tie bars. Tie bars provide stability to lugs, keep them from shuffling under power, and allow treads to effectively bite into the ground.

Bead Bundles: The steel-wire bead bundles that hold a tire to the rim are also important in delivering engine power to the ground. Inadequate bead performance can cause the rim to slip inside the tire, burning up horsepower and fuel, and reducing tire life. The shape, gauge, and design of Alliance's bead bundles are a secret weapon in creating high-performing tires.

Pressure to Perform

To get the most traction out of your tires, it’s imperative to operate them at the proper pressure. Overinflating a tire reduces the size of its footprint and stiffens its sidewalls, reducing both its footprint (and thus its ability to bite for traction) and the efficiency of transferring an engine’s power. Conversely, an underinflated tire can compromise the consistency of a tire’s contact patch, even lifting the center of the tire off the ground. Other issues with underinflated tires include decreased lateral stability, an increase in heat buildup (the #1 enemy of tires), extreme pressure on the bead, and over-torquing the sidewalls. 

Few items on the farm will return as much on their investment as a $5 tire gauge, provided you use it. Don’t believe us? Check out our Tireside Chat: The Value of a Pressure Gauge and see for yourself!

Learn More About the Alliance Agriflex+ 372 

Application-Specific Tires

We're an industry leader in application-specific tires. Whether you need a high-traction solution for operating in the muddy rice fields of the South, a tire that perfectly balances the need of traction and flotation for the fields of the Midwest, or a solution for the steep slopes of the Northwest, we have the answer. Contact your local dealer or rep today to get a grip on the options available to your operation.