Agricultural Tire Deflection and the Impact on Traction, Flotation, and Appearance

Technical Bulletin

MAXAM on Tire Deflection and the Impact on Traction, Flotation, and Appearance

AG Technical BulletinWhat is Tire Deflection and why is it important for both traction impact & flotation impact? How does the grower fully maximize deflection?

All agricultural tires either radial constructed or bias / conventional constructed are designed by size or footprint to fulfill following specific functions:

  • Carry the Load
  • Transmit the torque (or driving power)
  • Resist the lateral forces
  • Allow the chosen equipment to fulfill its purpose whether in a powered or towed function

By design, radial tire construction accounts for 20% of the carcass load or pressure on the soil, while the compressed air in the tire chamber accounts for 80% of the carrying capacity. Radial tires therefore always rely on compressed air to carry the given load. How do we know that the air in the tires is carrying the load? By the shape of its sidewall deflection or “tire bulge” under a given load.

What is Tire Deflection?

Tire deflection is the amount of “bulge” the tire lowers under load as the weight or torque is applied to the tire by the equipment axle. The deflection is the calculated difference in height between an “unloaded” tire section height and the “under-load” tire section height normally measured from tread face/shoulder to the wheel flange. The deflection amount or percentage is the difference between the two heights.

In simple terms, if the tires are under light load or in an “unladen” condition the footprint becomes smaller as the sidewall deflection is minimal. As the weight or load increases on the tire and the deflection increase, the tire footprint becomes longer along the tread face contacting the soil.

The tire deflection created by managing the correct air pressure for a given load or speed will adjust the tire footprint length or size increasing both the tractive power (traction) or flotation (ground pressure) ensuring the tires can deliver the optimal performance. In some instances, tires may appear to be under-inflated, when in fact they are “deflecting” at the sidewall to ensure the tread face is providing the correct gross flat plate delivering every ounce of performance the tires were designed to convey.

A grower can maximize his tire deflection by having a clear understanding of the weight and speed he or she will be applying on his tires for any given load. Adjusting the air pressure to ensure his tire deflection and resulting footprint is optimized to his working conditions will allow him to achieve:

  • Traction (reduced fuel cost)
  • Flotation (reduced compaction = greater yield)
  • Faster through the field (labor cost)
  • Improved tire life (tire value & wear life)

MAXAM agricultural tires are designed to deliver an optimized footprint ensuring the best possible traction and flotation for the grower’s powered and towed vehicle needs. MAXAM’s growing family of radial and bias-ply tires deliver performance solutions tailored for the agricultural industry. Backed by a world-class warranty program our radial agricultural tires are designed to deliver the value our customers expect from MAXAM. Try the MAXAM Advantage in your field today!

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