Radial vs. Bias Irrigation Tires: The Differences?

There are various options to choose from when choosing new irrigation tires. Read our guide to learn the difference between radial and bias ply tires.

Published on
February 5, 2021 9:01:53 AM PST February 5, 2021 9:01:53 AM PSTth, February 5, 2021 9:01:53 AM PST

Let’s talk about irrigation tires. We’ve discussed tractor tires in previous blogs, but we have yet to dive into the world of irrigation tires. There are three main problems when it comes to irrigation tires: they go flat, get stuck, and leave ruts. Knowing the differences between radial and bias ply tires can make choosing the right tire much easier. Since buying new tires is an investment, it is important to make the most informed decision. Keep reading if you’re interested in learning more about what makes these two types of tires so different. 


Different Types of Tires

Although there are two popular options in the irrigation tire department, bias ply and radial, there is also one more option. High-density polyethylene tires, or “no flat’s” as they are more commonly known in the industry, are another choice for your irrigation system. Non-directional bias tires are another up-and-coming alternative we have seen emerge in recent years. The benefits for non-directional tires are not having to worry about which direction tires are mounted and less rutting because mud is not as easily displaced. However, since bias ply and radial tires are the two most popular options when it comes to irrigation, let’s explore the differences between them. 


Radial Tires Explained

After the radial tire was invented, things were forever changed in irrigation. The innovation of the radial tire is great for irrigation due to its design. With radial tires, the sidewall and the tread function as two independent features. Dawson Tire and Wheel brought radial technology to the pivot irrigation world. The primary advantages to choosing a radial tire is reduced tracking and a higher load capacity. This is beneficial to crops, as some tires can leave ruts over a foot deep. Having huge divots and ruts all over the fields may result in reduced yield and the potential to cause damage to your farm equipment. 


Radial tires have the potential to last two to three times longer than other tires because the cord plies are positioned at 90 degrees to the direction of travel. The sidewall is independent of the tread, which means it has more flex and a wider track. Having more contact area with the ground results in better weight dispersion, and ultimately reduced rutting. Another fact about radial tires is that they require lower air pressure than their bias counterparts. Radial tires can be set to around 15 to 18 psi. Because radial tires have more flex, they are less likely to puncture or get stuck out in the field. While radial tires are a great option for irrigation, they are typically more expensive than bias ply options. 


Bias Ply Tires Explained 

Although bias ply and radial tires serve a similar function, they do have some noticeable differences. Bias ply tires have multiple rubber plies that overlap one another, meaning that the crown of the tire and sidewalls are not independent. Bias ply tires are thick and stiff. Because of how bias tires are designed, they have less flexibility and tend to cause deeper ruts. This is something to keep in mind, as it may affect the longevity or function of the tire over time. Radial tires seem to out perform bias in nearly every aspect, however, the cost savings of a bias ply tire may be worth the short falls to many ag producers.


Why Choose Radial?

While it ultimately depends upon the soil type and amount of water applied during each pivot rotation, there are many clear reasons to choose a radial tire. If tracking/ rutting is a concern in your field, the reduced air pressure and increased flexibility of a radial tire will be beneficial. If your field primarily consists of sandy/ loamy soil, a bias ply tire should work just fine.  


Bias ply tires typically have a shorter tread life than radial tires, so while cost savings upfront may be appealing, it may not necessarily result in reduced cost overall. While bias ply tires are still a good option, radial tires have dominated the industry since their introduction.  


Tire Options

There are many options to consider when choosing which tires to buy for your irrigation pivot system. Now that you know the these key differences, you can assess which option is best for your farm and application. If you are in the market for irrigation pivot tires, check out Dawson Tire and Wheel. We have many cost-efficient options for top industry manufacturers including: Vortexx, Petlas, Trelleborg, Firestone, Rainmax, and many moreDawson Tire and Wheel is home to a no-flat pivot tire option called Rhinogator. Composed of high-density polyethylene and coated with a UV protectant, these tires are a great option for softer soils and minimal water applications. We also offer our own brand of radial, bias, and bias non-directional tires called Vortexx® which boast a five year warranty.  


At Dawson Tire and Wheel, we are fully invested in the ag tire business. Feel free to reach out with any questions you have regarding our multiple brands of irrigation tires or any other agricultural tire and wheels.