Evolution Wheel

A Deep Dive Into Pivot Tire Sizes

Written by Evolution Wheel | Dec 1, 2022 3:25:07 PM

Traditionally, a tire with a wider profile has more floatation, while a tire with a taller profile can dig deeper. Choosing the right size pivot tire for your irrigation system is a matter of following this simple rule.

Deep Ruts

Deep ruts, or pivot tracks, are inevitable when operating a center pivot system. The tires on the center pivot irrigation system travel over the same path repeatedly. As the tires travel, they dig into the mud under the system's weight, creating ruts.

Deep ruts create problems for irrigation farmers as they can damage the irrigation system and tires and get stuck, not to mention the damage to the crop going into the field to fix whatever problem the ruts are causing.

Tire Sizes

14.9 x 24 Pivot Tires

A standard solution farmers use to address deep ruts is changing the pivot tire size. The most common solution is a wider pivot tire. 14.9 x 24 is the most popular size; however, 16.9 x 24 is also an option in extreme cases.

The wide profile gives the tire more floatation as it spreads the irrigation system weight over a larger area. This means that it will take longer for ruts to develop to the point of damaging your machine. The problem with wider tires is that they damage a larger area of crops increasing yield loss.

11.2 x 38 Pivot Tires

The other solution is to use a taller tire. 11.2 x 38 pivot tires are the most common tall tires on the market. Making the tire taller gives the tire more clearance before damage occurs to the machine. It also means the tire damages less crop than the wider version.
 
Tall pivot tires still get stuck and become flat in the field, causing more headaches for farmers. A flat pivot tire is a huge issue. They fill with mud, damage drive trains, and even damage the tower due to drag. Replacing these tires takes time and money and often requires a tire shop with specialized equipment to be serviced.
 

EWRS-PIVOT Series

Another option is to use an airless tire like the EWRS-PIVOT Series airless irrigation tire. They are designed to prevent ruts from forming in the first place. This pivot tire is a 14.9 x 24 true-to-spec pivot tire with bi-directional tread and a concave profile.
 
Most pneumatic pivot tires have a concave profile where the tire center curves toward the edges. This shape pushes dirt out from underneath the tire, resulting in ruts. The EWRS-PIVOT Series' open profile holds dirt underneath the tire as it travels, preventing ruts from forming in the first place.
 
The EWRS-PIVOT series is also serviceable. They are composed of rubber segments that attach to a high-strength rim. This allows the operator to change out damaged segments when needed. It eliminates downtime due to flat or damaged tires. Since the EWRS-PIVOT Series is serviceable, it lasts the entire tread life span.