At first glance, farms may not look much different than they did decades ago. From an operational standpoint, however, they are changing significantly. Each farmer is covering more ground than ever due to consolidation, while equipment is getting bigger and heavier.
As a result, large farm tires are undergoing changes, as well -- and radialization tops the list. "Bias is losing to radial at an increasing rate," says Terry Speck (in photo), co-owner of Bowling Green, Ohio-based Speck Sales, which has carried farm tires since the 1950s. "I don't sell as many bias tires as I used to in the larger stuff."
"We're selling very few (large bias) tractor tires anymore," says Bill Schaefer, co-owner of Tandem Tire & Auto Service in Potosi, Wis. Reasons for the bias decrease vary.
But bias tires aren't ready to give up control of the large farm tire market just yet.
Radial revolution
There aren't as many new applications for bias farm tires as there are for radials, according to Mark Pillow, Goodyear Tire & Rubber Co. marketing director, farm tires. Pillow calls large farm tire radialization "the natural evolution we've seen in other segments of the market."
"We're hardly selling any 20.8x38s" in bias, says Schaefer, "and no more 20.8x42s. It's been going that way for the past five or six years." Tandem Tire's Potosi location services farmers in Iowa and Illinois in addition to its home state.
Price is a major factor, according to Schaefer. "The pricing of radials seems to be getting closer to the pricing of bias tires."
Five years ago, the price of a radial might exceed the price of a bias unit by $150, he says. Now the average difference has fallen to between $75 and $100.
"Bias is slowing down for us," says Bob Graham, president of Spencer, Iowa-based Graham Tire Co., which has 22 outlets in Iowa, Nebraska, South Dakota and Minnesota. Radials tend to perform better in situations that require high levels of traction, he says. "Most farmers know the differences between" radial and bias farm tires. "There used to be questions about radials, but that's a thing of the past."
"For years, large farm tire radialization has stood at 12% to 13%," says Ray Evans, executive vice president of engineering, marketing and sales for Titan Tire Corp. "In the original equipment market, it's 70% or more," though he notes that radialization at both the OE and replacement levels has taken place slowly.
Bias benefits
Bias tires are far from obsolete, according to tire manufacturers. "If you look at the United States market today, about 48% (of the large farm tire segment) is radial," says Pillow. "If you go back five years, that segment was 42% radial. I don't know how much further the big bias segment will radialize in the U.S." Radials comprise 63% of the large farm tire market in Europe, he says, "but they do a lot more road travel over there."
Pillow predicts domestic large farm tire radialization will top out at 70% to 75% within the next five to six years. "There will always be a spot for bias." Ninety-percent of the overall North American farm tire market is still bias, including front and rear tires, according to Goodyear statistics. "There's still a wide base for them."
Bias large farm tires still offer advantages when it comes to certain applications, say tiremakers and dealers.
1. Old tractors "are designed for bias tires," says Len Wagner, manager of field engineering for Firestone Agricultural Tire Co. (FATC) "Bias tires are still the best choice for older tractors because they void power hop," which is frequently induced by using radials on aged models.
Equal weight distribution between the front and rear axles of older tractors is difficult to achieve, according to Wagner. And there are plenty of old tractors still in use. "Farm equipment, especially tractors, doesn't seem to get retired. When a farmer buys a new tractor, what does he do with his old tractor? He keeps it," often for decades.
2. Combines remain popular bias applications. "We're almost 100% bias on combines," says Tandem Tire's Schaefer. "Lots of combines are coming out with OE bias tires."
"The only place I'm selling many (large bias tires) is on combines," says Speck. His combine tire customers tend to prefer bias construction. "Their biggest complaint with radials is that when they're going down the road, they get too much rocking back and forth. Over the years, I've had people who put radials on their combines and were uncomfortable, so we put bias tires on." Speck now steers combine owners toward bias units. "It's not much fun changing tires the second time around."
3. Flotation-oriented applications like fertilizer applicators and manure spreaders benefit from bias tires. "Flotation is a key buzz-word, especially this past year," says Titan's Evans. "We had a wet spring and a lot of equipment couldn't get out in the field. And when they did, it was too wet. Summer turned out to be dry and we had the reverse problem: stubble. Stubble can be pretty brutal. Stalks dry and (become) little spikes. Eventually they'll pierce the carcass and cause a flat."
In addition, there's still a demand for bias tires to outfit smaller equipment like pulling tractors, according to Goodyear's Pillow.
Specific tire attributes ensure bias viability in the large farm tire segment, including:
1. Durability. "Bias tires (provide) some degree of resistance to hazards like stone bruises and the snagging of sidewalls by stumps," Wagner says. "The bias sidewall is stronger than the radial sidewall; it can handle more."
2. Stability. "About half of our market is hilly," says Frank Anderson, president of Frank Anderson Tire Co. Inc., a single-location dealership in Columbus, Ind. "You have to watch" when using radials on severely uneven terrain, "especially on high center of gravity machines like combines," due to rim deflection and other factors.
3. Cost. Despite shrinking price disparities, bias tires are expected to remain less expensive than their radial counterparts. "Why would someone with an old tractor want to put radials on?" says Evans. "He doesn't have to spend the money."
"Some of these rims on old tractors can't take the stress that radials put on wheels," says Anderson. For activities like bush-hogging, mowing, grinding, auger and elevator work, and "utility jobs around the farm, it just won't be cost-effective to go radial."
"Statistically, the bias farm tire is very viable," says Bill Haney, technical customer service support representative for Trelleborg Wheel Systems. "There seems to be a core group of bias sizes," ranging from 14.9x24 through 20.8x42, "that are popular in the states. There are literally thousands of tractors that these sizes fit."
The decision to go with bias or radial sometimes depends on tractor horsepower. "If you go above 120 hp or 125 hp, the trend is a very high percentage of radials," says Anderson. It's more of a 50-50 split on models with less horsepower, he adds.
Size and plies
How much bigger can large bias farm tires get? Tiremakers continue to push the envelope as farm equipment increases in size and evolves in function. "I just did a pair of tires for a fellow with a new combine that holds 330 bushels," says Speck. "His old combine held 200 bushels." Common bias sizes in northwest Ohio, where Speck's dealership is located, once included 23.1x26 and 28L26. "But 30.5x32 is probably the single most popular size for us these days."
"As equipment gets larger, there's a need for more robust tire construction to handle heavier loads," says Titan's Evans. Farm tire equipment manufacturers "are looking for greater load-carrying capacity, which means more plies and heavier beads."
As a result, farm tire makers are building products with higher ply ratings. "Years ago, 12 plies used to be the upper limit for ag tires," says FATC's Wagner. "Now we're seeing up to 20 plies."
And Wagner expects ply ratings to increase a little more. Many rims in the field "will not readily accept tires with heavier ply ratings. They will have to be redesigned." Any increase in plies will have to be done in concert with OE equipment manufacturers, he says.
Farmers also want tires that comfortably fit between rows of their crops, according to Speck. "They don't want big, wide metric tires." Most rows in his service area are 30 inches wide. "Radial or bias, they want a (narrow) tire."
Tall, narrow tires also reduce soil compaction, which is a growing concern. "Ten to 15 years ago, I don't think farmers were as aware about the effects of compaction as they are now," says Speck. "Every farmer I know considers it to be a factor."
Large bias farm tire design is relatively stagnant, according to manufacturers. "Construction has pretty much matured," says Goodyear's Pillow, adding that most end users who demand higher load carrying capacities are switching to radials. "All we're doing is tweaking what we have. We're not putting a lot of research money into bias."
However, Tandem Tire's Schaefer has seen a shift in bias tire tread designs. Manufacturers "are moving away from long bar/short bar (configurations) and going toward long bar designs." Why? "Short bars wear prematurely on the road." Road-ability, of course, remains a primary concern. "Very few farmers in our area have one farm," says Speck. "A large farmer has 1,000 acres or more, and that might be in eight or nine different fields 30 to 40 miles apart."
Both manufacturers and dealers agree that large bias farm tires' place in the market will remain relatively secure -- despite the proliferation of radials. "There will always be a spot for bias," says Pillow. "Let's face it, a radial will always be more expensive than a bias. We'll continue to see it shrink, but the bias segment will never go away."
