Several factors are driving the radialization of the ag tire market, according to Dave Paulk, manager field technical services, BKT USA Inc.
"No till and minimum till farming are two of them," he says. "Radial tires (also) perform much better and provide a longer tire life in many applications. This has also been a driving force. Although they are more expensive, the cost-per-hour of use is lower."
Paulk, who notes that increased flexion (IF) and very-high flexion (VF) technologies are being used more, says "radials are preferred in row crop farming because of higher speeds and higher weight carrying capacities. Radials are also used in sileage and manure hauling applications. These are on the highway for much of the time and run at higher speeds."
According to Paulk, though radials are used on some two-wheel drive tractors, "they are predominantly used on MFWD (higher-horsepower) and four wheel drive (4WD) tractors."
Some of the smaller MFWD’s (compact tractors) use bias-ply tires, he adds. But "in the case of MFWD on the higher horsepower tractors, both fronts and rears are radials. Full time 4WD tractors run the same size all the way around and most use radials.
"Implement tires have seen a big swing towards radials because of the size and weight of the implements and the speeds they are driven," he says. Radial implements are used on planters/seeders, chisel plows, cultivators, manure spreaders (wet and dry), sileage carts and grain carts. "Some bias (tires) are still used, but this segment has become more radial."
More benefits of radials
"Being able to run lower air pressures to minimize ground bearing pressure and soil compaction is a big selling point for radials," says Paulk.
Radials also "have a flatter footprint and provide more traction in the field. This leads to less slippage and less fuel consumption. Radials run smoother on the road and won’t wear out as quickly. They dissipate heat better and run cooler."
Paulk says radials are "more forgiving on air pressures, as maximum air pressure is often not required. You can run at higher speeds."
He adds that "there are some areas where bias work well and have an advantage over radials."
For one, bias ply ag tires "are less expensive than radials. The sidewalls of the bias tires are stiffer and stand up better. This minimizes rocks and sticks damaging the sidewalls when bushhogging and mowing. Stiffer sidewalls (also) have more stability on hillsides than radials."
The rounded shoulder doesn’t tear up grass as bad in pastures.
Bias ag tires are used on chore tractors or secondary tractors, says Paulk, who adds that you "generally see bias tires used in dairies, feed lots in hay (raking and bailing), and mowing."
