R-1 or R-1W: TIRE MANUFACTURER’S ANSWER

 

 

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

In the ag industry traction tires are classified by the depth of tread using the nomenclature R-1, R-1W. This industry standard allows tire manufactures to work within the standardized classifications so machine manufacturers and end users can properly compare tires. The R-1 has been the standard general farming tire for decades. Tread depths for R-1 tires depending on the size will run from 1.25” to 1.75” deep depending on the size of the tire. R-1W is of European origin, some call it the European R-1. R-1W tires are generally 20%-25% deeper than a standard R-1

That being said the question then arises what are the benefits of both and what applications are best for each. Typically on smaller HP tractors (<150HP) the manufacturers will fit the tractors with the R-1. These tractors are used in lighter more general applications. In addition R-1 tires tend to be less expensive and more cost effective for the manufacturers. However, R-1 tires do tend to perform better in some applications. In applications where the tires will see dryer harder conditions the R-1 will outperform and outlast the R-1W in most cases. R-1W’s perform better in softer slightly wetter soil conditions and typically clean better in those wetter conditions.

For example, a self-propelled sprayer is a good candidate for R-1 tires. The 25% deeper lug of the R-1W tends to leave deeper lug or cleat marks in the field and when making turns on the end rows they tend to rut and disrupt the residue more. During long transport runs the deeper lugs tend to heat up and flex more causing premature wear. Another example would be in scraper applications where due to the deeper lug of the R-1W in the high torque hard surface application the taller lug tends to be more unstable and flex causing lugs to sometimes be torn from the tire.

Up until now there has not been an R-1 choice for operators on the larger volume tires for larger tractors in the more arid regions, scraper applications or larger floater options for sprayers. The entire market has been R-1W’s. Titan is introducing the Optitorque Radial R-1 line expansion coming out with the 710/70R42 and 800/70R38 sizes for those operators and applications that an R-1 will outperform the R-1W. At the end of the day it really is up to the end user to determine the conditions he is running in and determine what tire they should be using and what will work best for them. They also need to make sure when comparing tires and tire brands, some may be comparing an R-1 to an R-1W , the good news is now at least, they will have more choices.

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Originally, the standard pattern was the “R-1” type and the “R-1W” (“W” stands for “wet”) was seen as the specialist for wet soil types with approximately 20% more tread depth. Between 1950 and 1975, developments were made in the agricultural tire business, such as the standard fishbone pattern and the radial agriculture tire. During this time, the “W” type became more popular and the preferred type for many farmers around the world. Today in many regions, the R1-W is the “standard” pattern with some tire lines only available in the R-1W pattern.

A reason for the R-1W preference may be that farmers expect 20% deeper tread to provide a 20% longer lifetime. Additionally, due to the more aggressive pattern, they may expect higher traction on the field.

With improved tire technologies and changes in operation today, this logic is not quite valid. From a wear perspective, the individual tread design and compound properties are much more important than the difference between R-1 and R-1W. For example:

• Comparing R-1 and R-1W, the deeper tread patterns often have smaller lugs, so the amount of rubber material withstanding wear is often the same on both tread types. In the end, this should result in comparable lifetime.
• To have proper self-cleaning with heavy soil types in combination with deeper tread, the distance between lugs needs to be greater. This also reduces the amount of rubber withstanding wear on the R-1W types.

The amount of road transportation and transport speeds have increased during the past 20 years. On the road, the R-1 can have the advantage:

• On average, they have a wider lug surface making contact with the road/hard ground which allows a better force transfer.
• Lower lugs allow better intersection of the lug front on the road without trouble for self-cleaning on the field. This allows tire designers to optimize rolling comfort properties with less limitations, such as noise and vibration.

Of course, tractors are mainly designed to work on the field and less on the road. So, let´s look at the differences between R-1 and R-1W in field applications.

Soil types are quite individual. Even the same soil type can have different characteristics depending on the thickness of different soil layers, the distance to harder underground layers, and individual and changing weather conditions that impact humidity content. A general recommendation for R-1 or R-1W based only on soil type cannot be made.

As the “W” for “wet” says, 20% more tread depth shows significant traction advantages, especially on wet soil types where the lugs sink completely into soil. This additional traction is only given if the soil between the lugs is compressed properly though. If the soil is too dry, or the ground underneath the loose soil is too hard, the compression of the loose material won’t occur in the interlug section. In this situation, a lower tread depth will compress the soil a little bit more allowing additional traction force to be transferred, like the following picture displays.

Recommendations for Farmers

Lifting the implement, driving over an exemplary soil area and “reading” the imprints of the tire from time to time can tell farmers about the situation of the “gear-pairing” between their specific soil condition and tires. This builds up expertise for the next tire selection.

If the traction forces don’t deem an advantage of one type over the other, consider the increased risk for wrinkles in the connection between the lug and tread base associated with higher lugs.

Another factor that needs to be considered for the choice between R-1 and R-1W is the application. On many soil types, especially when wet, the “W” type can generate better traction. But for many applications, the traction is not the limiting factor, such as seeding applications or PTO-driven implements. Here a wider and more even footprint of the R-1 or even a partly worn tire causes less impact to the soil, which needs to be eliminated by the implement.

One quite special and sensitive application is the grassland operation where deep and sharp lugs can cut the turf surface. The effects from this may make the track areas unusable if mud or earth could be picked up in the silage and harm the fermentation. The right tread design and tread depth is very important here.

A good example to always use the optimum tread depth is practiced in the Netherlands. They have an active sale and resale market with realistic prices for used tires. In wet soil areas for tillage and ploughing, new R-1W tires with less than 50% wear can be used. Afterwards the partly worn-down tires are welcome to be sold in their wide areas of grassland farming with wet surface conditions that are highly sensitive. They are used in this grassland application until worn down completely.

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

First what is a R-1, R-1W, R-2, HF-1, F-2 etc.? It defines the tread pattern of each tire and follows norms/rules established by TRA (USA) and ETRTO (Europe). R-1 and R-1W are the tread patterns used mainly for traction in agriculture and is the typical lug type design. The main difference – defined by norms – is that the lug of an R-1W tire is 20% taller than the lug of an R-1. R-1W is an evolution of the R-1 that started in Europe as the soil conditions there are normally more humid than in the U.S. From there the W in R-1W means WET.

Each tire manufacturer has it’s own lug design (width, length, angle, shape, quantity) and follows his experience and development to provide the best traction capabilities in each soil condition. Trelleborg with the exclusive Progressive Traction (PT) line up adds an additional small lug in the base of the normal lug providing an additional anchor point. The result is an improvement in traction increasing the power transfer from the transmission to the soil. This wider lug base also increases the damage resistance of the lug.

Most Europe based tire manufacturers – as Trelleborg – offer a complete Radial R-1W (WET) lineup, combined with the flexible sidewall tire construction, that deliver a flatter tread profile than conventional R-1 tread pattern. This design provides a larger footprint on the ground, with more and longer lugs contacting the soil at the same time and deeper into the soil. This provides a higher traction (less slippage, less fuel consumption) and lower compaction on the soil compared to R-1.

Having a tire that can perform under wetter condition without compromising performance expands the working window available for each job.  Also, another advantage of R-1W is as the lugs are 20% taller and a flatter profile, the tire has a longer and more even lug wear life as conventional R-1.

There are some cases where a R-1 lug height design performs better than a R-1W. This is the case with sprayers and spreaders. This equipment is traveling at high speed with full load on the road (hard surface) where all the pressure is on the lugs only. This high lug movement on hard soil generates higher amount of heat (worst enemy for tires) accelerating the wear of the lugs. In this specific case the tire manufacturer created sprayer specific series (Trelleborg with TM150) with a R-1 lug design height, but increased the number of lugs. This concept allows the load to be distributed on more lugs and generates less heat with faster dissipation.

Finally, it has been a custom to use the R-2 design (taller lugs) in muddy conditions like in rice fields. The traction performance and grip are superior in these muddy field but was not adequate at all for not so muddy soil condition or road transport. The lugs would suffer high stress, bend with higher damage possibility, higher wear and very uncomfortable ride. Trelleborg in order to offer an alternative to these conditions has developed and launch recently to the US market the 480/80R50 TM600 Rice PT with a new and innovative R-1W+ profile. These lugs of these tires are taller than the “normal” R-1W but shorter than a R-2, combining the positive aspects of both tread pattern (R-1W and R-2) and the exclusive Progressive Traction concept from Trelleborg.

In sum, always think about the specific application when choosing whether to use R-1 or R-1W.

CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Why would a dealer recommend an R-1W over an R-1? Why would a farmer buy either one?

The difference between the R-1 and R-1W is the tread depth. The “W” designation stands for “Wet” and has approximately 25% deeper tread depth. Remember this is an approximate! The reality is that when comparing tread depths between different product lines from the same manufacturer or from different manufacturers, there are most likely other design differences than just the depth of the tread. These differences should be a primary concern in the buying or selling process. Tread depth should be a secondary concern.

The primary objective should be to identify the best product for the application, period! Making the best choice can only be achieved by identifying the application as well as the features and benefits that are needed or required. Does the specific application require increased load carrying capacities, high speed capabilities, maximized traction, flotation . . . or does it just need to hold air for the application? The application and features required should drive you to the best product. The answers may lead you to bias, radial, high speed, flotation, row crop, IF, VF or even IF CFO product lines, among others.

In the majority of cases, multiple tread depths are unlikely to be a factor in making the purchasing decision.

Comparing the various options based on a cost per 32nd of tread depth helps with cost comparisons. The R-1’s will cost less due to reduced tread depths which translates to less rubber in the tire. Don’t get caught pricing a “tire” against another “tire” without the details or you may get caught appearing to be out of the market price-wise!

Tread depths can enter in the buying decision where the equipment is only operating in dry conditions or is not utilized in applications requiring maximum power to the ground, or other high-performance features.

No farmer plans to operate their equipment in wet, muddy conditions but when they have to, they would be better served with R-1W’s over R-1’s due to the additional traction the deeper lugs can provide. Dry conditions either stay dry or go to wet and wet conditions only stay the same or go towards the dry side with time. Amazing! It’s much better to be prepared with the deeper tread depth radial tires for wet conditions because down time during harvest season can really hurt the bottom line.

If you are comparing costs of an R-1 vs an R-1W you should see at least a 25% price gap to seriously consider the R1. The R-1W has about 25% more tread depth and in the majority of applications, the increased tread depths will deliver a longer service life that will correspond with the increased tread depth percentage. Keep in mind when you start with an R-1W you can run the tires for quite some time and with the right amount of tread removal, you will then have your R-1.

If pricing is the only consideration, then the cheaper the better. But the cheapest tire may end up being the most expensive in the long run. We tend to get what we pay for.

What is the best buy? It is very simple . . . the correct tire for the application and operation. The tire that provides the performance and trouble-free service life that fits the farmer’s needs is by far the best option.

Just keep in mind . . . a deeper treaded R-1W might provide a bit of insurance against wet conditions when it is needed the most!

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

Before the R-1W was introduced to the U.S., there was an R-1 and R-2. The R-1 was designed for general farming, while the R-2 was designed for extremely wet conditions such as with rice and sugar cane (Rice and Cane tire). These tires were used before radials were popular and bias tires were most common.

As equipment got larger and heavier and farming practices changed, bias tires gave way to radial farm tires in most types of farming. Radial tires are designed to carry heavier loads at less air pressure and generally last longer when they are driven on the highway. Because of the body construction, bias tires have a tendency to squirm and wear out quicker when run on the road.

The R-1W was originally designed as a fit between the R-1 and the R-2. The R-1W has approximately 20% deeper tread than an R-1 and 20% less tread than the R-2. With today’s tire and compounding technology for radials, the R-1W is used where both the R-1 and R-2 were used with bias tires.

The R-1 is designed for general farming in dry dirt as the tread depth is not as deep. The R-1W is also used in this application and has a 20% deeper tread, providing a longer tire life. This is important because farms are now scattered and tractors must be transported on highways to move between farms.

R-2’s were designed for muddy conditions and is still the tire of choice for crop such as rice, cane, and vegetables in irrigated soil. In some of these conditions, the R-1W is used where the dirt is wet, but not muddy. The R-2 does not do well when they are driven on the road because the lugs are deep, bend easily, and can develop uneven tread wear.

The R-1W is a good all-around tire to use for general farming practices. BKT makes this tire with a 45-degree angle that does well in the field and rides and wears well on the highway. The extra tread depth gives it longer wear and more value for the money paid.

Radials in general are better than bias tires where soil compaction is a concern because they can be run at lower air pressures with higher load carrying capacities to lessen soil compaction. BKT radials are designed with a flatter footprint to distribute weight evenly. BKT also makes tires in the IF and VF design to lessen soil compaction where needed. The IF carries 20% more weight at the same air pressure as a standard tire and the VF carries 40% more weight at the same air pressure as a standard tire. Less air pressure equals less soil compaction, producing better crops.

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

R-1W tires have taken the farm tire market by storm, and it’s no mystery why. Just a few years ago, these extra-deep-lug farm tires were super-premium offerings, reserved for the biggest tractors and the largest farmers. Now, most of the top tire manufacturers have R-1W tires, prices have come down, and the deep-lug technology is within reach of most farmers.

When it comes to extra traction, heavy loads, and lots of torque, R-1W tires are the way to go.

Think of an R-1W as a classic R-1 directional tractor lug tire plus 20 percent more depth. The “W” in “R-1W” actually stands for “wet,” to indicate its increase in wet traction versus a traditional R-1. That’s perfect for Midwestern or Southern soils—gumbo soils or sandy loam where you want more bite. That R-1W lug is going to grab more earth and propel the tractor forward more effectively, while the area between the lugs keeps the tire on the surface of the soil.

And nowadays, with fields spread farther apart, it’s nice to have some more rubber to extend tire life on equipment that spends more time on the road. Beyond the extra depth, today’s R-1W tires also have better compounding than ever, which is great for longevity.

That said, sometimes all a farmer needs is a good, classic R-1. Say you’ve got a small chore tractor in your equipment yard—70 horsepower, loader on the front or a box scraper on the back—that doesn’t even leave the farm. You don’t need an extra-deep lug tearing up the ground for that. And if you’ve got a tractor that’s just pulling a tedder and a baler around a hay field, you don’t need the added expense of an R-1W. Basically, you’re not going to wear out that R-1 tire on a haying operation, so why pay more for extra tread you’re not going to use?

Another situation where it may be better to stick with R-1 tread rather than going to R-1W is on a high-clearance sprayer. The deeper R-1W lugs on a 380/90R46 tire will squirm more than the shallower ones on an R-1 of the same size. Obviously, that’s a disadvantage when you’re trying to run straight between the rows or steer a few thousand pounds of spray solution down the road. The R-1 will give you a more stable ride and build up less heat on the road between fields. Definitely a better choice for that application.

On the other hand, sometimes you want even more lug than an R-1W can deliver. In the muddy fields of rice and sugar cane in the South or sugar beets in the North, some farmers invest in R-2 tires, which have massive lugs more than 3 inches deep.

An R-2 tire works differently than R-1 and R-1W tires do. Instead of floating the tractor or combine up on the surface of the soil and reaching in for traction, R-2 lugs actually dig deep and scrape a layer of mud off the surface, clawing for drier soil below where they can get traction. The angle and lug design are extremely aggressive—more aggressive than you’d want in a drier field, especially if you are trying to stick to minimum tillage or no-till.

Working with a tire dealer in Arkansas, Alliance just designed a revolutionary R-2 tire. Our new Agristar 374 R-2 tire delivers great traction, excellent self-cleaning—which is vital to keep tires from turning into clay-coated racing slicks after their first rotation in heavy, wet soils—and outstanding performance on the road. The old R-2 standards that have been on the market since the ’60s are poor performers on the road: the deep lugs gave a bouncy ride, and because they were so tall, they tended to squirm a lot. That also built up a lot of heat, which, as we know, is a sure way to kill a tire.

We completely redesigned the lug on our new R-2 tire. It’s deep—105/32″—but we’ve built it with a stair-step-style construction, tapered out at the bottom and anchored to a lug bar in the center of the tire to minimize squirm. Those truncated stair-step shapes also provide more biting edges in the mud for extra traction, and a wide nose on each lug smooths out the ride and improves steering even further. And everything about the sidewalls enhances the tire’s performance, from enhanced heat dissipation to extra flex that maintains a flatter, more even footprint for better traction and longer road wear.

So if you look at the variety of lug tractor/combine tires on the market—from standard R-1s to the extra 20 percent depth of an R-1W to the massive R-2 that is a full 3 inches deep—you can really take your pick of the tire that’s going to deliver the performance you’re looking for…and paying for.

Precision Inflation, LLC
Ken Brodbeck, Vice President of Technology

When should a user select a R-1 or R-1W? See the comparisons below:

R-1W over R-1:

1. 20% more life, especially if the machine does a significant amount of road travel.
2. Better tractor resale value.
3. Minor loss in traction over R-1 on firm dry soils.
4. Minor traction advantage in wet muddy conditions.
5. Eventually R-1W will become an R-1 tread after roughly 1000 hours.
6. Rear Sizes over 80” in diameter are only offered in R-1W.
7. Soil Compaction is directly related to tire pressure. R-1 and R-1W use the same load/pressure table. To minimize compaction, know your axle load and set the tires to the minimum pressure required by the tire manufacturer and check weekly. If you do not check tire pressures regularly, you should run 2 to 3 psi higher than the minimum to protect your tire investment.

R-1 over R-1W:

1. R-1 bias and radial are usually the lowest cost tires for low hour use tractors.
2. R1 treads are the favorite for most tractor pullers due to better grip on hard pulling tracks.
3. Think of a high horse power tractor puller using a slick with ¼” high tread bars. They win on firm tracks!
4. Older lower horsepower sizes may only come in R-1 tread.
5. Soil compaction, see point #7 above.

What about R-2 – Rice and Cane Tread?

1. R-2 tires work well in true mud with a solid plow pan.
2. In mud without a plow pan, you quickly bury the machine.
3. R-2 tires are expensive, rough riding on pavement and do not pull as well in normal moisture soils.
4. How about for “insurance in wet harvests?” You will probably be better off buying a large flotation size to keep tire pressure low and float over the soft spots.

Michelin Ag
David Graden: Operational Market Manager – Agriculture

R-1 and R-1W are tread designations used to describe a tire tread bar typically a corresponding usage. Most common designations found are R-1, R-1W, R-2, etc.

R-1 is a standard tread and typically used in applications that demand very little from the tire. For example, you may find an R-1 lug tire in dry farming or on general purpose chore tractors. And in some applications, conditions need to be ideal.

R-1W is typically considered a wet traction tire for use in softer soils. This lug design can have larger voids between lugs and deeper lugs than an R-1. These tires are also considered a deep tread or premium option for most tire manufacturers.

Here at Michelin AG, we only make R-1W tires. When it comes to putting more horsepower to the ground and improving traction in your less than ideal everyday conditions, let’s be honest. Think spring planting. No one has the luxury of working in ideal conditions. The standard R-1 just isn’t enough.

Take a look at the lugs on your AG tires next time you get the chance. What you will notice is an almost A-framed design, sweeping up at an angle from the front and the same angle back down along the trailing side. The basic reason for this type of lug design is stability. Unfortunately, as this type of lug wears, the biting edges will round over and eventually create a lug that resembles an angled bump instead of a tread bar.

The standard Michelin R-1W, however, will maintain those biting edges and deliver exceptional traction when up to 70% worn with up to an additional 50% tread life. The Michelin lug design is really to blame for this exceptional performance. Not only do Michelin rubber compounds tend to wear slower, but more rubber tends to bring longer tire life. Additionally, the upright nature of Michelin lugs leaves a very consistent shape throughout the entire life of the tire. This translates to traction, which in turn, burns less fuel by operating more efficiently.

Finally, since R-1W is the designation for all Michelin AG tires, our standard tire pricing isn’t far off from our competitor’s standard tire pricing. Meaning, you could purchase a Michelin Agribib 2 for a very comparable price as our leading competitor’s standard tire. The difference is you are getting much more tire at an even better price with Michelin. After a few years, you’ll have an R-1.

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When choosing to place radial traction tires on a tractor, one of the most common questions we hear is whether R-1 or R-1W tires are best. When looking at the price difference between the two tire types, farmers wonder what they get for the higher price of an R-1W. To help farmers make the most informed decision, here are some facts and performance benefits for R-1 and R-1W tires.

The language itself, R-1 and R-1W, is a tire industry standard defining the minimum designed tread depth of an agricultural traction tire. The Tire and Rim Association defines the minimum bar height based on the tire width and the aspect ratio (height of the sidewall). The R-1 designation is the standard tread depth. The tread depth of an R-1W tire is at least 20 percent deeper than the same sized R-1 tire. In simple terms, R-1W tires have a taller bar height, but all the other dimensions, such as overall diameter and rated load capacity, are the same between the R-1 and R-1W tires.

There is not a substantial performance difference between the two types of tires – particularly for farmers who are concerned about soil compaction. Soil compaction is the result of the axle load and the inflation pressure to carry the axle load. Since the two tires have the same load and inflation pressure, the tires will create the same amount of soil compaction. If farmers are concerned about soil compaction, it is more important to look at tire sizes or IF and VF tires that carry the axle loads of their tractors at pressures below 15 psi.

1. The traction difference between the two tires depends on the soil conditions in which the tires operate. The deeper R-1W tread depth does not automatically mean the tire has more traction. Traction is dependent on tread bar shape and the angle of the bars. However, when deciding between the types of tires, pay close attention to soil conditions and consider the following:
   Dry or normal soil moistures can use an R-1 tire. The R-1 and R-1W tires will have similar amounts of traction. Both tires work great in these soils, but if a farmer is debating the two tires because of cost vs. performance, the R-1 tire is more cost efficient.
2. In wetter soil conditions, even if they are borderline, consider using an R-1W tire. Just like in dry soils, the R-1W tire doesn’t generate more traction over the R-1, but the deeper skid will help maintain traction in higher slip ranges. The extra cost of the R-1W helps ensure traction in those areas, which helps with time and fuel efficiency.
3. In wet soils, like those in the Texas Bayou or the Gulf Coast region, neither the R-1W or the R-1 are the best choice. Instead, farmers could look to move up to an even deeper tread on R-2 tires. The tread depth of an R-2 tire is two times deeper than R-1 tires to help gain traction in those wet soils.

After considering the soil conditions, think through how often the tractor will be running on paved surfaces like the roads or concrete feedlots. If a farmer doesn’t have to drive many miles on the road to get to their fields or doesn’t operate in a concrete feed lot, then an R-1 tire is a good, cost effective solution. If a farmer does travel long distances to get to their fields, or if the tractor operates in concrete feedlots, move to an R-1W tire. The deep skid will allow the farmer to put more hours on the tractor before the tires need replaced.

Above all, consult with your local tire dealer to determine what type of tire works best in your area. It’s not always necessary to move to a more expensive type of tire based on traction or performance claims. If the conditions allow it, sticking with an R-1 tire may be a way to reduce costs in equipment maintenance.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.