‘Kickin’ the tires’ on equipment trades

Progressive Dairyman Editor Lynn Jaynes Published on 22 December 2017
tractor tire tread depth

You’re ready to trade off a piece of farm equipment, or trade for another farmer’s iron. You’ve looked at the “blue book” value and searched similar sales on various internet sites. You think you are fully prepared to make a bid. But you’d be wrong. You’re not prepared until you’ve made some inspection of and determined value for the tires.

Times have changed. Tractor horsepower increased from 150 hp to 500 hp in the past 15 years, and tractor speeds went from 15 mph to 40 mph. Fifteen years ago, a BKT 460/85R38 radial tractor tire was considered a big size (69 inches in diameter at 327 pounds). Ten years ago, the Firestone 480/80R46 radial tractor tire was considered big (77.2 inches overall diameter at 497 pounds). Today “big” means tires up to 90 inches tall and 55 inches wide. The knowledge you had when you were first educated about tires is now sorely out of date.



As you assess tires on used equipment you are purchasing or trading in, consider these points – all of which affect the value of the total trade:

  • Tire size – Is what’s mounted on the equipment adequate for the horsepower and speed? Are you sure?
  • Tire brand – Top tier-one brands for holding value are (in no particular order) Firestone, Michelin and Trelleborg. These brands maximize the value of the machine. Middle range tires would include Goodyear, Mitas, Alliance, BKT and Dawson.
  • Tire model – Note the tire model. For instance, if it’s a Goodyear brand, is it a Super Traction, Dyna Torque or Ultra Torque?
  • Tread depth – Tread depth is the vertical measurement between the top of the tread rubber to the bottom of the tire’s deepest grooves. In the U.S., tread depth is measured in 32nds of an inch. Just make sure you’re measuring in the middle of the tire rather than toward the outer edges, which may give an inaccurate measurement and portray the tire as better than it really is.
  • Casing soundness – Check for weathering, cracks, cuts or stubble damage. Even if the tread depth is adequate, check for other tire damage. When corn is a big part of the growing crop, a lot of tires can have adequate tread but be pockmarked with stubble damage or other rips and tears related to weather or use stress.
  • Replacement price – Consider the current price for this tire in new condition.
  • Are tires matched – When duals are mounted, is the inside tire valued the same as the outside tire?

Figuring tire value

Once you’ve completed the initial assessment, the life of a tire can be measured in thirds.

First third: The tire will have 66 to 100 percent tread depth. At this stage, tires still hold value and life. Dealers that provide trade-in solutions, for instance, would still be interested in trading this tire and reselling it. Users will still benefit from this tire being on the machine. These tires are low-risk to both the user and the dealer.

Middle third: The tire will have 33 to 65 percent tread depth. This tire has life, but does not add much value to the equipment. Dealers that provide trade-in solutions would be hesitant to trade this tire. Resale value is questionable. From a user aspect, it might be a gamble using it on moving equipment.

Last third: A tire at this stage has 0 to 32 percent tread depth. It’s “bald.” This tire has minimal life and no value. No one wants this tire. Most dealers pay fees to have these types of tires removed from inventory, and most users immediately look for replacements on moving equipment for safe operating.


Tread depth

If you’re unfamiliar with a specific brand or tire model, don’t guess at tread depth; guessing doesn’t work. While it’s too much to ask users to be an expert on tires, resources are available from tire manufacturers and dealers.

To accurately measure tread depth:

  • Take a straight-edge object and lay it across the top of the tread bars. You can use a 32nds gauge or a tape measure that measures in 32nds (i.e., 1 ½ inches should read 48/32).
  • Measure from the straight edge that is sitting on the tread bars down to the casing of the tire.
  • Three measurements are needed: one in the center of the tire and one on either side – about half way out to the edge of the tire from the center.
  • The average of these three readings will give you the number you need to divide the new-tread number with. The new-tread number can be obtained from dealers or from manufacturer websites.

Recognize damage

Today’s farm tractors and implements move at faster speeds than ever before. And a tractor tire or sprayer tire blowout at 40 mph is much different than a blowout at 15 mph. Sidewall bubbles are frequently associated as causing blowouts. A sidewall bubble is a bulge protruding from the sidewall of the tire. It is caused by air leaking from the inside of the tire into the body of the tire. If a bubble in the sidewall is present, it’s a major safety concern. These tires are significantly weakened and blowouts are imminent. Especially on dual-mounted tires, check the sidewalls of all tires – especially those mounted on the inside where weaker tires are commonly placed.

Learn to accurately recognize tire damage, and don’t make the mistake of determining wear by hours used. A tractor or piece of equipment might be represented as only having 500 hours of work on it, “so the tires are still in good shape.” However, variables in work situations are wide – was it used in construction, in cornstalk stubble, in hay fields or light road traveling? Tires wear differently under different circumstances.

Tires hold value in ag equipment trades, but it’s easy to significantly misjudge their value. On today’s four-wheel-drive tractors, misjudging the tire value can be a $40,000 mistake if eight expensive tires have to be replaced.

It’s worth the time and effort to take a closer look when kickin’ the tires on used equipment.  end mark


Lynn Jaynes
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PHOTO: Tread depth is the vertical measurement between the top of the tread rubber to the bottom of the tire’s deepest groove. This helps you determine what the life of the tire will be and when it might need to be replaced. It all factors into the overall value of the equipment. Photo by Lynn Jaynes.

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