AG Tire Talk
AG Tire Talk How to reduce road lope on sprayers Modern Tire Dealer has partnered with AG Tire Talk to provide answers to the insightful questions farm tire dealers have about farm tire technology. Launched by tire industry veteran James Tuschner in 2016, www.agtiretalk.com gives agricultural tire manufacturers competing in the U.S. the opportunity to answer each question, and help their dealers better connect with their customers. A trending question followed by an abridged version of the answers will appear in our Commercial Tire Dealer section every other month; for the complete answers, check out www.agtiretalk.com!
Question: In sprayer applications, what is your recommendation to improve driver comfort and reduce road lope? Bradley Harris, manager of global agricultural field engineering, Firestone Ag Division, Bridgestone Americas Tire Operations LLC: With the high center of gravity of high clearance sprayers, operators tend to feel more roll and sway of the vehicle compared to a tractor. This feeling is amplified when narrow tires are installed and the vehicle is transported down the road with half a tank of liquid. Firestone Ag recommends to all customers to follow these guidelines: 1. Use the appropriate section width tire on the machine. When the machine is not in the field with a current crop, purchase and use the OE-approved flotation tire with a width of 520 mm (20.8 inches) to 800 mm (30.5 inches). 2. Use IF or VF tires. IF- and VF-marked tires carry more load at the same inflation pressure as the same-sized standard radial tire. 3. Tender the sprayer at the field. Don’t travel down the road with product in the tank.
Road lope occurs when the wheel assemblies have a high and low spot. When changing tires on these machines, it becomes important to make sure the tire/wheel assemblies are concentric — centered on the centerline of the axle — to prevent road lope. Norberto Herbener, OE applications engineer, Mitas Tires North America Inc.: Road lope is produced when equipment bounces during transport, forcing the driver to reduce speed. Tire quality, design, and incorrect end user usage are a few causes of road lope. There are many solutions to solve the issue. Tire technology has evolved at a rapid pace, changing the mind-set of tires being a “black doughnut” to a complex and fundamental part of equipment. As agriculture equipment has grown over the years in size and weight, users have requested
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a larger footprint for less compaction to protect their farm land. This has also been a trend for sprayer users to request width options to minimize damage to the standing crop. As a solution to this issue, VF (Very Flexible) technology was introduced and allows for an increase of 40% on the load capacity at same pressure and speed or a 40% reduction in inflation pressure at same load and speed. As we know, the load capacity of a tire is dominated by the volume of air in the tire. The more air at higher inflation pressure, the higher the load carrying capacity. This is the reason why sprayer tires have been evolving not only to incorporate VF technology, but also to introduce higher aspect ratios, for example the 380/105R50, keeping the same width and rim size but higher load capacity. This characteristic, combined with very flexible sidewalls increases the contact area and ride comfort. In summary, the best way to resolve the issue of road lope is to ensure use of the correct inflation pressure. James Crouch, marketing specialist, Alliance Tire Americas Inc.: A smooth, comfortable ride is better for sprayer operators in two important ways. On an immediate level, it reduces driver fatigue, which helps keep their reflexes sharp and their driving safe. And a machine that doesn’t shimmy or bounce down the road is much easier to control, which helps keep everybody safer. On a longer-term level, studies of equipment operators in other industries have found that oscillations at 4 to 8 vibrations per second transmitted by machinery from the ground surface can be amplified by the driver’s body, which can cause back and joint pain. High-amplitude shocks — like a jolt from hitting a rut in the field — can also contribute to injury and strain. At the Alliance Tire Group Inc., we’re addressing ride quality and rode lope sprayers in several ways with our Alliance Agriflex+ 363 VF row-crop tire. First, the block-style tread pattern is optimized for a smooth, stable ride on the road because we recognize that half of a sprayer operator’s time can be spent on pavement or gravel, getting from field to field and back to the loading pad. The heavy center rib, evenly
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