Should I Choose a Radial or a Bias Farm Tyre?

Agricultural tyres continue to evolve to meet the needs of today’s farmers, but whether to choose a bias or radial tyre remains a nagging question. So how do you make the decision of whether to save a few extra dollars by staying on older-fashioned bias tyres, and when are the features and benefits offered by radials worth the investment? Read on for some facts that may help you feel better about your decision.


Though the technology is nearly as old as pneumatic tyres themselves, bias-ply tyres still present a viable option for many machines. They are manufactured by lapping multiple plies of rubber diagonally over each other—also called “on the bias”—to create a single working unit. Because of the way bias tyres are engineered, the tyre’s sidewall and tread are connected and work together rather than independently.


The advantage of bias construction is that it creates a stiff, strong, durable tyre with rugged sidewalls, making it a great choice for machines threatened by stumps and rocks, or equipment that requires a lot of stability—for instance, tractors that often drive across hillsides. Bias-ply tyres are also typically less expensive than radials. Negatively, the stiffness of a bias tyre also means that bumps in the field are transferred throughout the entire machine, diminishing a tractor’s ride quality. And because of the way the diagonal plies transfer movement across the tyre carcass, when a bias tyre’s sidewall flexes, so does its tread, reducing traction and potentially increasing damage to your field.


Over the years, radial tyres continue to claim more and more of the global farm tyre market. As machinery has gotten larger and more powerful, radial tyres have been better able to meet the demands made of them by today’s heavier equipment. Unlike bias tyres, radial tyres are constructed in two parts that are designed to work independently of one another—the body plies run perpendicular to the bead, and the undertread area is wrapped around the tyre’s circumference by radial belts of fabric or steel. The belts create a broader, flatter footprint and provide increased resistance to tread punctures.


One of the distinct advantages offered by a radial tyre’s two-part design is that flex in the sidewall isn’t transferred to the tread, allowing for better traction, increased fuel efficiency, and reduced soil compaction and field damage (radials can have a 15-25% larger footprint than a bias tyre). All these qualities ultimately add up to more productivity and efficiency around the farm. Radial tyres will also last longer and provide a smoother ride than bias tyres.


Similar to the way radial tyres came to be globally accepted by overcoming the limitations of their bias-ply forbears, today’s IF/VF (Increased Flection/Very High Flexion) tyres are being produced to meet the new challenges facing today’s farmers: namely, larger and more powerful machinery and an improved understanding of the negative effect soil compaction has on yield. Simply put, IF/VF tyres are a radial with a sidewall engineered to allow for more flex. Because of this, IF/VF tyres can carry a higher load than conventional radial tyres. Furthermore, they can be used at a lower tyre pressure, allowing the tyre to create a larger footprint which improves traction, reduces slippage, and lessens soil compaction.


Of course, for radials and IF/VF tyres to outperform their bias counterparts, it’s critical that they be operated at the correct tyre pressure—so if you’re going to invest in a good set of radial or IF/VF tractor tyres, pick up a good tyre gauge at the same time.


Whether you’re looking at a bias, radial, or IF/VF tyre for your next farm tyre, Alliance Tyre has a bunch of great choices for your machine. The Alliance FarmPro 324 is an excellent option for farmers looking for an affordable do-everything bias-ply tyre. Purpose built to handle the numerous jobs tractors are tasked with around the farm, the 324 is a reliable, durable, and affordable option that’s ideally suited for general use tractors. As for radials, we’ve got a wide range of designs, from classic tractor lugs to our venerable Alliance 550 MultiUse, which is designed to handle whatever job you throw at it. In the field, the Alliance 550 provides great traction, low compaction, and excellent stability while also being capable of achieving high speeds on the road. The Alliance 354 IF/VF is one of our most advanced tractor tyres, with the ability to carry between 20% (IF) and 40% (VF) more load than a conventional radial as well as the ability to run using 20% (IF) and 40% (VF) less pressure than conventional radials.


Still wondering if a bias or radial tyre is right for your equipment’s needs or want to learn more about Alliance Tyre’s other great farm tyres? Contact TyreZim today to find the right tyre for your machine.