Yokohama Rolls out Latest Off-Highway Radial

March 15, 2023

Matt Wolfe

Yokohama announced a new off-highway radial tire as well as new sizes for existing tire families at CONEXPO 2023 in Las Vegas. The Galaxy Hippo all-steel radial high-traction loader tire was the most prominent announcement from the company’s press conference at the show.

"We think of rock tread for most loaders, but many of those machines are working in dirt, whether it's on construction jobs, demolition sites, or on farms," said Dhananjay Bisht, National Product Manager—Earthmoving, Construction and Industrial Tires for Yokohama Off-Highway Tires America, Inc. "The new Galaxy Hippo all-steel radial brings a dirt tread to the category to deliver the extra traction many loader operators need."

Radial revolution

Traditionally, loader tires have featured a bias ply construction over radial design. However, Yokohama believes that the new radial version of the Galaxy Hippo offers significant advantages in both puncture resistance, traction and wear, while maintaining stability that operators expect from their tires. It will be available in 20.5R25 and 23.5R25 sizes.

“What we realized in the market is that everybody is moving from a specialized machine to an all-purpose one,” said Bisht. “So they need a tire that allows that machine to work on as many surfaces as possible. With bias ply tires, there are still a lot of constraints. But, with a radial, we can offer a tire that allows customers to go from agriculture to construction without changing tires.”

Bisht also explained why Yokohama decided to develop the radial version of the Galaxy Hippo. “It was determining how you differentiate in the market,” he said. “And how we could bring that value and price point to so that the customer will be convinced to go from bias to radial. Everything is better with the radial version of this tire. You get better life, cost per mile, and overall performance.”

Yokohama stated that in field testing, the radial Galaxy Hippo outlasted bias-ply alternatives by as much as 50%. The company also highlighted that the radial construction permits retreading, which further extends the service life and lowers the total cost of ownership. The company also claims that the radial version is four times more resistant to punctures.

Not treading lightly

While designing the radial version of the Galaxy Hippo, Yokohama made significant alterations to the tread pattern. The radial’s lugs are reportedly thicker than those on the bias-ply version that are nearly perpendicular for maximum traction along the outer portion of the contact patch. The radial also features buttressed shoulders for additional traction.

“The bias tire featured lugs that were very prominent on the shoulder,” Bisht explained. “When you look at the contact patch of a bias tire, it trends towards the center. So the shoulder of the tread was never coming into play. To get any traction we had to increase the tread depth on the shoulder.”

Bisht continued, saying “With the radial construction, we can increase the footprint, provide a flatter cavity, and increase the tread arc, which will give the tire a wider face when it is touching the surface. When we compared this tire to our bias tire, we found that we were getting 7% more tire touching that ground with the same size tire. There is also less traction drop off as the [tire] wears because more of the tire is doing the work.”

The center portion of the tread lugs are curved to form an angled overlap, which according to Yokohama, provides more steady road manners and reduced wear at speeds up to 25 mph (40 kph). The nose of each lug was also widened, which produced a smoother and more stable ride while also reducing scrub wear when operating on hard surfaces.

“These tires are used for high torque application,” said Bisht. “So if you’re using a lug based tire, you have to give it this strong construction to sustain that torque. You have to give the lug base strength, and the lug angle is also designed to give it the strength to sustain the load and the torque.”

Bisht also described the self-cleaning capability of the tread design. “How the tire cleans is an agricultural concept,” he said. “The depth and depression (of the tread) defines how the tire cleans. So that is an angle we have to consider when we are designing a tire for this type of machine. We extended the lug in the center so that both the leading and trailing lug are touching the surface. There is much more continuity in terms of how much tread is touching the surface with the radial design than any bias tire.”

Sizing up

Yokohama also announced new sizes to their existing lineup at CONEXPO 2023. The RT41 radial will now be available in the 875/65R29 size. Yokohama claims this new size provides “extra width for added traction and stability.” The new size also reportedly features a unique multi-layer, cross-ply belt package that is woven with flexible steel belt wire.

Yokohama also claims that the L-4 tread blocks of the RT41 are 50% deeper than comparable L-3 designs, which adds service life by reducing heat buildup. Service life is also reportedly extended thanks to the abrasion- and cut-resistant rubber compound.

Yokohama also announced the 29.5R25 size for the RL52 loader radial. The RL52 is intended for high-capacity loaders in quarries and surface mines. Yokohama touts its RL52 loader radial as a “rugged L-5 radial for front-end loaders.”

The RL52 features a cut-resistant cap compound and flush tread design that Yokohama claims minimizes wear from abrasion. The RL52’s design also features rock tread lugs with a low lug-to-void ratio and buttress side protection to help prevent sidewall cuts and snags.

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