Radial Tires vs. Bias-Ply Tires

A radial tire is a tire that the body plies run radially across the tire, perpendicular to the circumference of the tire. That allows the tire to flex more and permits a bigger footprint.

Radial tires have reigned supreme in agricultural work for almost 50 years, after emerging in the 1970s and besting the bias-ply tire design. These are almost always the ideal solution for large, heavyweight tractors and farm equipment, and agricultural users can get more work done faster in the field.

The radial farm tire design offers a bigger footprint and is designed to provide a smoother ride on different surfaces.

The more pliable radial tire construction increases contact area and will allow the tire to exert greater traction. It distributes weight more evenly and it’s more adept at handling off-road or wet road surface conditions.

Radial tires have lower rolling resistance - it takes less effort for the tires to roll over the terrain - so they build up less heat and achieve greater fuel economy. Radial tires with AD² technology can carry even more load at lower inflation pressure.

Again, radial tires better dissipate and manage their heat when in use. This helps the tires run cooler, improving tread life, and lengthening the overall lifespan of the tire.

Radial tires have a larger footprint that distributes weight more evenly over large areas.  They can also operate at lower inflation pressures than their bias counterparts. Agricultural users can achieve less soil compaction and greater crop yields with this design by managing inflation pressures to match the load to the required inflation pressure.

Agricultural tires are a long-term investment. Radial tires achieve longer and more even tread wear and are more resistant to cuts and punctures in the tread making repairs less often and sometimes designed to resist cuts and punctures in the tread. Combine that durability with better heat management, and this tips the scales for the radial tire.

There are few drawbacks of radial tires relative to their bias-ply counterparts. The cost of radial is sometimes higher leading to a larger starting investment and there may be certain use cases where radial isn’t the best for the terrain or desired usage.

Unlike the radial tire, bias-ply tires are engineered with a crisscross pattern of overlapping body plies, typically at 45-degree opposing angles. Bias tire construction allows the sidewalls to be more rigid and may provide more stability in extreme hill side applications.

While radial tires have set the industry standard for nearly 50 years and out-perform bias tires in most cases, the bias-ply tire design does still have a few advantages in select situations.

First, the bias tire construction is simpler than the radial, and so it tends to cost a little less. The bias tire design can be a cost-effective option for certain older secondary farm equipment. Second, the bias-ply tire design tends to have a stiffer sidewall that resists punctures, so if your work poses high risk for sidewall punctures this may be the tire for you. They can be beneficial for stability on particularly rough terrain at low speeds, like forestry and non-tillage work.

Bias tires may provide a lower upfront cost, but they have a faster wear rate and other drawbacks for common farming applications. They are designed to have less flexibility than radial which can lead to increased wheel slippage, reduced traction and provide a smaller footprint resulting in additional compaction.

Both tires can provide function and value based on individual application needs. Radial has become the standard in modern day agriculture but there may be times a bias is what your equipment needs. It is not a competition but rather understanding when and where to use each type of tire.

To summarize the difference between radial and bias-ply agricultural tires, here is a helpful table about the construction, benefits, drawbacks, and best uses for each type.

While some specific agricultural needs and equipment may call for the lower-cost bias tire option, in nearly all cases, we recommend radial tires for their longer life, smoother ride, and better outcomes.