After Laboring in Europe, the R-1W Came to American Soil – With Success

Multiple codes are used to define agricultural tires. R-1, R-1W, F-2, I-1 and HF-2 are commonplace in ag tire manufacturer, dealer and farmer circles.

These codes are used to quickly explain which types of soils the tire should be used in (R-1, R-1W), or where it should be placed on the equipment (F-2), or if the tire is for implement (I-1) or high flotation (HF-2) applications.

R-1 tires, designed for traction on dryer, well-drained soils where a shallow tread with many lug edges is ideal, have been around for quite some time. The R-1W, with its deeper, widely spaced lugs for wetter soils is also available to farmers – and it’s popularity is still increasing.

The R-1W got its start in Europe long before it was migrated to North American farms by European manufacturers like Michelin and Trelleborg Weel Systems. And, although it is designed for wet soil, American farmers are finding the tire to be very practical in several types of geographic locations.

Early Beginnings

The history of the R-1W agricultural tire began several decades ago in Europe. It originally came in the form of a bias tire for use in wet, sticky, clay-type soil conditions.

However, like many bias-ply tires before it, the R-1W morphed into a radial tire. From there, it really grew in popularity on European farms.

"I remember R-1W bias tires dating back to the 1960s," says Bill Haney, of technical customer service support at Trelleborg Wheel Systems. "However, they were expensive. Factory duals and tire sizes in general increased, which made premium tires like the R-1W bias less popular.

"In Europe, ag tire radialization started in the 1950s and became popular there well before it did in the U.S., which is similar to the slow start of radial passenger and truck tires in U.S. Also, in northern Europe the heavier, moist soils favored the development and use of R-1W radials."

The difference in soils between Europe and America is the main reason behind the R-1W taking nearly 20 years to catch on in the "new world." American farmers, while operating in drier conditions, have a much longer window in which to work.

"In general, the soils in Europe are wetter during the planting and harvesting seasons," says Dave Weed, applications engineer for agricultural tires at Goodyear. "This is particularly true in northern Europe, where the growing season is shorter than much of North America. This forces European farmers to work their fields when the soils are poor for traction.

"To handle these conditions, decades ago tire companies developed tires with deeper and more widely spaced tread lugs to facilitate traction. And it was only when the global market invited the import/export of equipment that the concept of defining different designs became reality. North America had already used the R-1 definition, so to describe the ‘European’ design, the R-1W was used, with the ‘W’ representing ‘wet.’"

Just as with all other radial tires, the R-1W in the U.S. didn’t catch on for a while. "The concept of an R-1W was introduced in the late 1980s for the North American market," says Chad Hake, vice president of marketing and sales, Michelin North America Agricultural Tires. The tire finally took hold when American manufacturers sold 710/70R38 sized tires to OEs for the European market.

"The Europeans require large single radial tires for their narrow roads and entrances into their fields," says Ken Brodbeck, manager OE/export sales engineering for Firestone Agricultural Tires. "The American tire and tractor companies then realized eight of these large tires on American 4WD tractors provide an excellent combination for reduced tire pressures and reduced soil compaction, along with great tread life."

"The R-1Ws were used mostly in large, single applications and offered better traction, less slip, better fuel economy and a very good ride. These features still hold true today," says Haney. "In North America, in climate zones similar to northern Europe, changes such as larger equipment brought about the need for better traction, longer travel distances and improved efficiency and economy – all the things the R1-W radial allows."

Operating Conditions

With drier conditions and a longer growing season in the U.S., the R-1W needed more than just a 710/70R38 size before it really caught on. But was it a confluence of events or a more specific reason that led to the R-1W populating American farms?

Even with North America’s dry soil conditions, there are always areas of wet, heavy, clay soils along rivers, behind levies, and around lakes. It’s these types of conditions that make the R-1W an optimal tire for many farmers.

"American farmers have rapidly come to appreciate the performance of this tire in the variety of working conditions they face everyday," says Hake. "The lug pattern typically associated with the R-1W gives long, smooth wear, which, when coupled with the additional tread depth, provides longer tire life."

Even with an overabundance of dry soil, Weed of Goodyear believes that the R-1W fits the bill for a lot of American farmers. "Heavy wet soils require R-1W designs for optimal traction," he says. "While the gross acreage of wet soils in North America is not nearly as large as the overall drier areas, the R-1W offers desirable value to a meaningful number of farmers."

Workable Benefits

Outside of operating extremely well in the wet, there are other benefits to the R-1W. It can operate at low pressure, has deep tread with good traction and – even if not exactly correct ®“ a perceived flotation advantage. All of these features have combined to make the tire very attractive to cost-conscious American farmers.

"The R-1W has approximately 30% to 60% more tread depth than traditional R1 designs," says Michelin’s Hake. "Many of the typical R-1W tread designs incorporate the 45º, long-bar/long-bar design, which means the lug size and spacing are equally distributed around the tread area of the tire. Plus, the tire is available in most all agricultural sizes."

Inflation pressure and ground pressure are always critical to farmers, who often find themselves working around high-dollar crops in places where extra care needs to be taken. "The amount of inflation pressure required for the tire is based on the tire size and the load," says Weed. "Ground pressure is equal to the tire inflation pressure plus one to two psi of equivalent stiffness, representing the tire casing stiffness as it deflects under load.

"The choice of using an R-1W should be based solely on the traction capacity of the soils and not one of any perceived flotation advantage compared to other designs, such as R-1, R-2, R-3."

Practical Application

Since the R-1W is still relatively new on American soil and its popularity is still increasing, farmers are probably still asking their dealers about what types of equipment they can mount the tire on and why. Any specific geographic region or type of crop requirements run a close second and third.

"This tire tends to be popular on large equipment and in most commercial field crops," says Trelleborg’s Haney. "Usually you will see these tures used with higher value crops and on higher productivity farms. The level of acceptance with customers is very high. Once they use them, customers like them very much.

"Up to now, they were mainly sold on larger equipment. But now tractors – especially the European ones ®“ are starting to come in with R-1W radials. Higher speed tractors are also better suited to the tires, with some rated as high as 45 mph."

"R-1W tires can be used on any type of farm equipment that would typically fit an R1 or R2 type of agricultural equipment," says Hake. "Geographical use is not limited to specific regions or types of crops."

Goodyear’s Weed prefaces any conversation about the best application of an R-1W with one economic caveat. "Europe has been steadfast in continuing to use R-1W design tires even though there are regions such as Spain, southern France, Italy, and others that could use a traditional R-1 tire with good results," he says.

"The world’s ag tire design is dominated by R-1W, and tire companies – to avoid tying up excessive capital by having two complete lines of R-1 and R-1W tires ®“ opt for the R-1W first. It will be that way until demand permits multiple designs. Under this scenario, the best traction choice is not always being made by the farmer."

However, Haney feels that, when in doubt, going with the R-1W is a better choice. "The R-1Ws favor moist soil conditions, and the dry land performance is acceptable," he says. "Even dry fields can have wet springs, so to default to the R-1W in dry conditions is a better compromise than, say, using an R-1 tire in very wet conditions."

With all of its pluses, the R-1W will continue to make greater inroads in North America and manufacturers will continue to push them. Anyone who doubts that need look no further than the radial passenger tire.

While North America was slow to embrace the passenger radial, once it caught on its popularity was unquestioned.