Implement Tires Earn Respect
By Jim Patrico
Progressive Farmer Contributing Editor
Pity the poor implement tire, little guy and unsung hero of the farm field. Tractor tires get all the glory with their giant lugs, flexing sides and imposing heights. But implement tires are the ones in the trenches. No bigger than truck tires, they carry the planters and the tillage tools, which are the reasons those fancy tractor tires are in the field in the first place.
Until recently, implement tires have been treated as commodities: Make them good but make them as cheaply as possible because farmers aren’t going to pay much for them. That meant using standard compounds and little in the way of new technology. Heck, the tires that come on a new $200,000 planter often aren’t even new tires. They are used truck tires that have been given some new tread to go off-road.
Suddenly, though, the attitude toward implement tires is changing. The work-a-day grunts are going high tech. They are getting sleek IF and VF bodies, and new compounds. Some of them are even getting Kevlar jackets to make them almost bulletproof.
What has changed the attitude toward implement tires is the change of environment in which they now work. The loads they carry today are huge; a 40-foot tandem disk can weigh 30,000 pounds. The fields themselves are filled with corn stubble that is tougher and sharper than it was just a few years ago.
"It’s like you are going across a field with bayonets every 7 inches," said Tom Rodgers, sales and marketing director for Firestone ag tires.
All of this led to problems of compaction building in fields when every bushel of yield counts and with tires going flat at the most inopportune times, like during a short planting window.
Farmers complained and manufacturers are responding.
"We do all this work on tractor tires so we get the psi down to 8 or 10, and make the tires squat to create a bigger footprint," Rodgers said. "Then we pull behind it what is basically a road roller, which creates all kinds of compaction."
That’s one way to describe implements and the tires they ride on.
Imagine a 36-row hopper-style planter that stretches 60 feet wide. When it folds, it rides on four tires that have to fit into a relatively small envelope—about 31 inches in diameter and 9 inches wide.
"Unfortunately, you have to inflate your tires to 100 to 105 psi to carry all that load," said Scott Sloan, ag product manager for Titan/Goodyear. "Once that thing [the planter] unfolds, you have these four tires that no longer have to be at that high psi … but they still are. Now you have these giant pizza cutters rolling through the field compacting the soil."
That’s another way to describe implements and the tires on which they ride.
The effect of compaction from implement tires varies, but it’s never good. "I have seen yield monitors [in a field planted with a 24-row planter where] … every 12 rows you see four rows that are lower yielding because of planter tires causing compaction," Sloan said.
Radial tires fight compaction by stretching a tire’s footprint to reduce pressure on the soil. Major tire manufacturers have been doing that with the big guys — tractor and combine tires — for years. They recently began offering the little guys — implement tires — the radial treatment.
Firestone launched its Destination Farm brand implement tires last year and now offers two versions in several sizes. IF-designated radials can carry 20% more load than a bias tire at the same air pressure. VF-designated radials can carry 40% more load than a bias tire at the same air pressure.
Titan’s new radial implement tires are the Goodyear FS24s, which come in several sizes. They are highway rated at 30 mph and have a load capacity of 6,400 pounds at 73 psi. Comparable bias tires have a load capacity of 5,616 pounds at 90 psi. The radial advantage is clear.
Michelin’s XP27 radials are sized exclusively for large implements like tillage tools. "The demand has really picked up because these machines are getting so enormous," said James Crouch, Michelin’s farm segment marketing manager for North America. He expects that’s a long-term trend: "Demand for premium radial tires will continue to increase because manufacturers are not going to suddenly start making implements smaller."
So far, radial implement tires are mainly available as replacements. Some shortline manufacturers have gone to radials as options on new equipment. Larger original equipment manufacturers (OEMs), however, have been slow to offer them.
Taller, wider tires with a larger air chamber would be an ideal long-term solution for compaction, Sloan said, because they could hold more weight with less psi. But such tires won’t fit in the envelope implement designers now reserve for tires.
"We have been telling them [OEMs] for years and years that as planters and tillage tools get bigger — if they keep that same size envelope — there is nowhere to go but up for inflation rates, which means more compaction."
He hopes OEMs might be close to making some major design changes. "I think you are going to see some pretty dramatic shifts in the next year or so in the way planters are designed to kind of open up that envelope."
Rodgers is not convinced: "There is certain [equipment] geography you can’t get away from. I think there will be some changes, but we are not going to see tractor-sized tires on implements."
Another possibility is to create an automated system that would lower the psi on carrier wheels when they are in the field and raise it again when they are in transport mode. The technology is available but so far not on the market. Of course, manual inflation changes are possible, if time-consuming.
The issue of stalk damage to implement tires has been around ever since new corn hybrids with stronger stalks hit the market. It reached a head for Titan a few years ago when Iowa farmer Mark Dimit complained loudly to the company that his two new planters suffered six flats in one planting season. His wasn’t the first complaint, but it struck a nerve. The following year, Titan gave him some new tires to test that contained Kevlar.
Part of the reason Dimit and others are having stalk damage problems is that implement tires must be dual-purpose tires. If they are to run on the highway, they must be constructed with soft compounds that can take the heat road friction generates. Hard compounds crack too easily under heat, and treads separate.
Yet in the field, soft compounds are at the mercy of today’s tough stubble. It pecks at tires and creates tiny holes and premature wear. In extreme instances, it will even puncture a tire.
Manufacturers typically order highway service tires primarily because of their ability to carry 20% higher loads at 30 mph, said Sloan, whose company (Titan) supplies the majority of implement tires to OEMs in the U.S.
"The highway service tires have to meet certain DOT requirements [they must be able to run safely at 30 mph, for instance], but stubble puncture resistance is not one of them," Sloan said. "When the tough stubble meets the softer, cooler-running highway tread, it created a perfect storm. We were really getting beat up."
WHAT TO DO?
Using steel belts and steel bodies is one strategy to make tires more puncture resistant; Firestone and Michelin both created radial implement tires with that type of construction to ward off stubble. The strategy allows the companies to create tires with radial configurations that are highway rated (30 mph).
Titan decided on a more unusual strategy. It used multi-ply nylon construction in its implement tires. In some of its newer tires, it doubled the number of plies and added belts made of Kevlar, the material used in bulletproof vests. "A bulletproof vest doesn’t have just one large ply in it, it has multiple layers," Sloan explains.
To complete the package, Titan engineers built the whole thing with a tractor tire compound that is resistant to stubble. Titan’s Stubble Guard implement tires cost 40% more than its other tires. But, Sloan points out, "In the heat of battle in planting season, you don’t want a flat tire, much less six; service calls are expensive."
Stubble Guard is not rated to run 30 mph on the highway but can be used for transport at lower speeds.
For tougher tires that are highway rated, Titan offers Goodyear Stubble Resistant tires with new compounds and nylon — but no Kevlar — belts.
With so many more options, implement tires are getting more respect.
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