Alliance Tire Americas
James Crouch: National Product Manager—Agriculture
Tires are so durable in the field that it’s easy to forget that they can be damaged if they are stored incorrectly. The big hazards are letting them get out of shape and exposing the rubber compound to degradation.
The best way to store tires is standing up. If you stack them, be sure not to put smaller-diameter tires on the top of the pile—they can damage the sidewalls of the tires below them. A good rule is to avoid putting a tire on a stack that doesn’t cover most of the sidewall area of the tire below it.
If your tires are mounted when you store them, over-inflate them by 5 or 6 psi for storage to help them retain their shape over the off-season.
Rubber compounds are susceptible to damage from hydrocarbons, so keep them away from gas, diesel, oil, paint, solvents and mechanical fluids like hydraulic or brake fluid. They can also be weathered by exposure to UV, so keep stored tires out of direct sunlight.
Ozone can also degrade compound, so don’t store tires near electric motors, welders or transformers, which all create ozone as they operate.
As you get ready for the growing season, inspect your tires carefully. Make sure you don’t have any nails or other objects wedged into the tire (you’d be surprised what can have escaped your notice). Check sidewalls for blisters that indicate separation or impact damage, and for slashes or cuts that could threaten the integrity of the casing. Look over your tread for wear, chunking or cracks.
And, of course, adjust your inflation pressure to the proper level for the load and speed you will be operating at.
Invest in a tread depth gauge. They’re not expensive, and they’re easy to use. All you have to do is rest the feet of the gauge on your tread lugs or blocks and extend the probe into the space between the lugs. The key is to do it several times at different places in each tire. That way, you’ll pick up indications of uneven wear, which are important for determining whether your inflation pressure has been correct, and whether you need to rotate your tires more frequently.
Examining tread depth is important in determining whether your tires are worn out.
There’s no real, set number for when a farm tire is worn out. Obviously, if you see cords or damage, it’s time for a new tire. But there’s a little wiggle room on tire replacement based on what you expect that tire to do. If you’re counting on great traction to pull a disk or a planter, you’ll need some rubber on those lugs to get a good grip—same thing if you tend to run in muddy or slick conditions.
However, if the weather is dry or we’re just talking about a chore tractor that you use to pull a feed mixer or haul things around the yard, you might be able to squeeze an extra season out of a set of tires that are down to 20/32″ or so.
Think of it this way: if you just bought a thousand-dollar hunting rifle or a new drone, you’d make sure you took good care of it and stored it out of the weather. Your tires are worth that much or more. Treat them accordingly and you’ll be protecting your investment and setting yourself up for good performance this spring.
Continental Agriculture North America
Albert Sumera, Continental Commercial Specialty Tire Technical Solutions
As with any other tire that will not be used for a period of time, agriculture tires must be kept in clean, dry conditions and ventilated premises away from direct sunlight. They must be kept away from any source of ozone (for example an electric motor or transformer); away from chemicals, solvents, and hydrocarbons that may affect the nature of the rubber; and away from any objects that may pierce the rubber (sharp or pointed metal objects or tools). They should also be stored away from flames or hot objects.
Tires should be stacked if mounted, to avoid damage due to tension or compression. If mounted on a vehicle, de-ballast them as much as possible and over-inflate by 0.5 bar (7 psi) versus the operating air pressure used. Before the start of operations next season, check the physical condition of the tires and adjust to the correct operating air pressure.
Agriculture tires are normally used for a long period of time, however in instances when there is an observed substantial slippage (approximately more than 15%) depending on the surface of operation, the tires may be considered “worn out”. Being worn out is relative to where the machine and tires are being used and there is no general principle that can be applied to every situation.
Agriculture Tire Tread Depth Measurement:
- Tread measurement should be made on properly mounted tires. Tires normally grow after first inflation. This effect is very significant the first few hours and can go on for the rest of tire life in minimal dimensions.
- Recommendation for precise measurements at “new” condition:
- Set air pressure to 2.0-2.5 bar (29-36 psi) at mounting
- Run the tires for a few miles on road at max tractor speed
- Adjust the air pressure to the operating air pressure
- Measure the tread depth the next day (24 hours later)
- Because of difficulty and variance in measurement of tread depth of agriculture tires, it is decided to use the center-line as the simplest measurement method.
1. Measure on four locations along the center-line of the tire (see image 2).
2. Use a flexible steel ruler to align with the round shape of the tire diameter by pressing the top of the ruler to the inside of lug 1 and the bottom of the ruler to the inside of lug 3 (see image 3). If a flexible steel ruler is not available, you can also use a hack saw blade.
3. Measure with a tire gauge down to the deepest point between lug 1 and 2 (see image 3).
4. We recommend measuring the tires every 500-1,000 hours, but the first measurement after fitment should be done earlier. During the first 100 hours the wear rate is generally higher (which is normal for all types of tires).
BKT USA, Inc.
Dave Paulk: Manager Field Technical Services
As spring tilling, spraying, and planting begins, farmers are reliant on good tires with minimal downtime. At this point of the year, downtime costs time and money- but before equipment is stored for the winter, there are things that can be done to minimize tire and equipment problems in the spring.
1. Tires should be checked for cracks, cuts, bulges, or any other type of visible damage. If there is any damage or possibility for failure, this gives time to replace or repair tires before they are needed again. Be sure to check tread depth. If the tire has less than 20-25% tread left, the tires may need to be replaced sometime during the next year. This gives the farmer time to budget for new tires.
There are several ways to measure tread depth. An OTR tread depth gauge can be used and bought through suppliers that cater to the tire business. Also, a straight edge with a ruler can also be used by laying the straight edge over the top of the lugs. Measure from the base of the tire to the straight edge with the ruler as close to the center of the tire as possible.
2. Make sure lug nuts are tightened to correct specifications. Check the bolts for wheel weights to ensure they are tight.
3. Inflate tires to the maximum recommended inflation pressure by the manufacturer for storage. Ambient air temperatures can cause air pressures to move up and down during the winter months when the equipment is not in use. Air pressures generally decrease in cold weather, causing the tires to go flat if they are not inflated enough. If tires go flat during the winter, the rim can damage the sidewalls by sitting on them. It is a good idea to check tires periodically while the equipment is stored to ensure they don’t go flat.
When taking the equipment out for use after storage, set air at correct recommended pressures to carry the weight of the tractor and equipment. This will ensure the tire is not damaged and will minimize soil compaction. Do not drive on flat tires.
4. Make sure tires are clean before storage. Clean the mud, sticks, and rocks from lugs and remove mud from the rim and weights (if wheel weights are used). In general, it is a good idea to store the equipment clean. When it is used again, it is ready to go.
5. If possible, it is best to store equipment inside in a cool and dry place. This keeps the sun, wind, rain, and snow from weathering the tractor and the tires. Ozone in the air and sunlight can cause rubber to age prematurely. It is best to keep rubber products away from electric motors, oils, fuels, and resins. If the tractor will be sitting for several months or more, it is best if the tires are not parked on rocks or asphalt. Rocks can damage tires if they lose air pressure. Also, asphalt is an oil-based material that will cause rubber to deteriorate over time. If the tractor must be left outside, cover the tires with a waterproof tarpaulin to avoid contact with ultra violet rays and bad weather.
There is really no cut and dried way to determine when it is time to replace tires based on tread depth. A tire that needs to be replaced in wet dirt may be fine in dry dirt. As tire lugs wear down, they can start slipping excessively which can increase fuel costs and time. Newer model tractors have wheel slip indicators where they should be in the 8-15% range, the closer to 8% the better. If the tire seems to be pushing dirt back behind it farther than normal, there is a good chance there is too much slippage. At this point, tires should be changed for optimal performance, and fuel and time savings.
All of these tips will help maximize tire life and minimize downtime.
Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW
Ag tires are designed to withstand the usage conditions of their respective application, but in order to achieve their full performance potential they must be maintained appropriately, which includes the condition in which they are stored in the off season in order to minimize the chance of experiencing an ozone/weather cracking condition over the winter months when the equipment is inactive.
Rubber compounds that are exposed to the atmosphere are formulated to resist deterioration caused by ozone. It may be hard to believe but the rubber compound properties constantly evolve due to their service and storage conditions. Improper storage can result in various tire conditions to develop including weather/ozone cracking also known as veneer cracking, dry rot, and weather checking if tires are not stored properly when not in use.
Ozone/weather cracking appears as a condition where small cracks/checks develop sometimes very quickly. This condition can appear from normal aging or late in its service life. It typically appears in higher stress areas on the tire near lettering of between the lugs.
Normally it does not affect the service life of the tire however, it can be aggravated by improper storage and/or exposure to high concentrations of ozone.
In order to help avoid potential tire degradation, maximize tire performance, and ultimately prevent premature removals, we generally recommend a few things to help minimize these types of conditions. If you think about what causes the condition, the surface of the tire or rubber with tension or stress and exposed to sources of ozone and UV light the common sense approach would be to eliminate those.
In a perfect world the best case scenario would be to block equipment off the ground to remove the load and let air out of the tires to relieve the stress on the tire surface. In addition, the unit should be stored in a covered environment away from sources of ozone which would include electric motors/machines, engine exhaust, welding equipment, battery chargers, transformers, and mercury vapor lamps. Other equipment that may produce sparks or electrical discharges should also be avoided. Covering the tires with an opaque wrap will eliminate the chances any UV light to attack the surface of the tires. I realize that it seems like a lot of work, but if you follow any of these suggestions or you realize you are accidentally exposing you tires to harmful elements you can take whatever counter measures to minimize the risks.
Depending on who you talk to and the applications, tires can run for decades and be literally smooth and they still perform the job just as well as the day they installed them. Of course those are rare but my point is that depending your performance expectation the idea of “worn out” may differ. Most companies will consider a tire “worn out” when the tread depth is less than 80% or 90% of the original tread depths. Warranties are based on this. If you are experiencing excessive reduction in performance due to lack of traction then it may be time to start shopping for a new set of tires.
Typically tread depths on Ag tires are taken across the center of the tire between the nose of the lugs. Using a depth gauge is the best way but you can use a ruler or tape measure with a straight edge to get the same measurement.
Precision Inflation, LLC
Ken Brodbeck, VP of Technology
Time to change horses?
Some things never change. Grandpa or Dad checked the team of horses every day. Adding new shoes, repairing a harness or replacing a feed box.
Grandpa spent 5 to 10 minutes every day caring for his horses. What if we spend 5 minutes per week checking our tires rather than brushing and feeding the horses?
At the end and beginning of the season:
- Check TIRE PRESSURE!! Inflate to recommended plus 2 to 3 psi for weather changes. A tire monitoring or On the Go Inflation System makes this simple!
- Check for any cuts or breaks in the tire tread, shoulder, sidewall and bead area.
- Is there irregular tread wear? This may stem from over or under-inflation!
- Store tires in a dark and electric motor/welder free area. Sun and ozone kill tires.
- Keep petroleum-based liquids and grease away from tires.
- Reset tire pressure at the beginning of the season for the machine’s heaviest load, such as a large front fold planter.
- At a minimum, check tire pressure once per week during use.
When to put the tire/horse out to pasture?
- When the R-1 or R-1W tire will no longer do the job!
- Excessive slippage in heavy drawbar applications
- Will no longer hold air and cannot be repaired
- There are numerous cuts or cracks into the tire cord body
- Your favorite tire dealer has a special rebate deal. A half worn tire may value to trade in for a new set of shoes!
- If you need to measure tread depth, choose the worst wear location, lay a straight edge across two tread bars and measure to the base of the tire with a ruler.
Our grandfathers took 5 minutes every day to feed and water the work horses, we should take 5 minutes a week to check our iron horses’ rubber shoes!
Michelin Ag
David Graden: Operational Market Manager – Agriculture
Over the years, I have seen many methods producers have used to either prolong the life of their tires or prevent the effects of winter storage on the following season. These would include parking their machine (tires) on wood or concrete blocks, taking weight off of the tires by raising the machine off the ground, covering tires with a sheet or tarp, increasing the air pressure to maximum psi, etc. The reality is, there are only a couple of simple actions a machine owner should take to help maximize the life of their tires and ensure optimum performance the following season.
After harvest season has come to an end, your machinery has been washed and you are ready to button up things for winter, I recommend parking your machine in a cool dry place. Washing your machine thoroughly will show evidence of any fluid leaking throughout the storage period. Additionally, make sure your tires aren’t sitting in chemicals, hydraulic fluid, fuel or oil. Petroleum based fluids will eat rubber and cause your tires to crack at the contact area.
Next, raise the air pressure of your tires to the maximum air pressure recommended on the sidewall of the tire. As the ambient temperature falls, so does the psi in your tires in addition to the natural loss of air pressure over time. When you return to use your machine, and pull out of storage for the season, reset your air pressures to the recommended psi. Your tire manufacturer representative should be able to assist you with this. As I have stated before, all Michelin Ag reps have the capability of weighing machines and recommending exact air pressures to help your machine perform exceptionally well.
Determining when a Michelin Ag tire is worn out is a great discussion with any end user. If you were to ask a producer to tell you when their tractor tires are worn out, they would probably give you a confused look and a response of, “When the tread is gone!”
Michelin Ag tires are standard R-1W with very specific rubber compounds and lugs designed to wear slower and more consistent than R-1 competition, as shown below. By design, when a Michelin Ag tire is deemed by many to be worn out, there is still plenty of tread with sharp biting edges with a consistent void ratio.
Rubber has a shelf life much like the bread in your pantry. Now that aromatic oils are no longer used in tire rubber, it begins to dry out as that tire ages.
For example, let’s say a typical tractor tire will last about 12 years, although the sidewalls are beginning to show significant age and reaching the end of their life- in many applications our tire will continue to complete the job efficiently with minimal slip due to design. Further, many folks would add a tube and use as much of the remaining tread as possible.
If you wanted to keep an eye on your tread and track my thoughts here, Michelin recommends taking tread measurements at the center of the tire, at the lug nose. If your tire pressures are set to recommended psi for the weight carried, your tires should wear nice and evenly across the face of each lug. If your tires are not wearing this way, you could have a mis-mounted tire or have a mechanical issue causing that tire to wear unevenly. Consult your manufacturer’s rep for recommendations or diagnostic.
Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer
After a hard season and harvest complete, it is now time to take a well-deserved break until the next growing season. This time of the year allows us to perform maintenance operations neglected during the growing season due to lack of time and prepare the equipment for a hassle-free performance next season.
It is important during this time to check your tires, as they are a key component of your operation. There are several points to consider when checking tires during the off season:
1 – Check for external damage that could compromise the tire’s structural integrity or performance. For example; nails, deer antlers, deep cuts, missing parts, etc. If any external damage is found, consult with your tire expert if you think it will affect the performance of the tire
2 – Check for correct bead seating on the rim and potential tire to rim slippage. If any issues are observed here let your tire expert assess the situation and correct if necessary.
3 – Check the bead area for material between the bead and the rim. If anything is found, be sure to remove it. If it’s difficult to remove let your tire dealer do it for you.
4 – Check the tire for signs of any uneven or excessive wear pattern that can be related to incorrect tire inflation pressure, incorrect tire size selection (that differ from a correct lead value depending on the tractor inter-axle ratio), excessive tire to soil slippage or damage/wear on steering components.
5 – Check the height of the lugs and replace the tires if the lugs are below 20-30% of its original height. The original measurement can be found in the tire manufacture data-book and web page. The lug height, or tread depth, is defined as 32nd of an inch and must be no less than 20-30% of the original value. If it’s below this value, the recommendation is to replace the worn-out tire. Low lugs significantly reduce the capability of the tire to transmit the equipment’s power to the ground, increasing the tire to soil slippage. The height of the lug can be checked by placing a flat plate between two adjacent lugs and measuring the depth of the inter lug area. This measurement must be taken at 1/3 and 2/3 of the length of the lug. Check in several areas of the tire.
6 – It is always recommended to store the equipment inside a shed and away from direct sunlight. Direct and prolonged exposure to sunlight can create superficial cracking and potentially dry out the tire.
7 – If possible, lift the equipment and place it on stands to allow the weight of the load to be released from the tires. You can also increase the inflation pressure so the tire maintains its round shape as much as possible. Take in to consideration that no tire is 100% air tight, so the tires will lose some air over time. Once the new season starts, recheck and adjust the inflation pressure to the recommended values depending on the equipment and application.
8 – If the tires are removed from the equipment to be stored during the off season, for example a floater set for sprayers, be sure to store them standing upright.
9 – Clean the tires as much as possible to remove dirt and other debris.
10 – Don’t allow the tires to come in contact with petroleum-based products or solvents.
11 – It’s recommended, when replacing worn out tires, to choose the same brand and size already installed for each axle of the equipment. This is because they are approved by the OEM’s. Tire specifications vary slightly between brands, even for the same nominal size, and it can damage your transmission if not chosen correctly. Also never mix radial with bias tires or R-1 with R-1W.
12 – In case you decide to change the size of the tires, consult with your equipment dealer to ensure the change is acceptable. Having a “non-approved” tire combination can damage your gearbox and final drives.
Always remember that the tires are a fundamental part of the equipment and taking good care of them will assure the correct, expected performance.
Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering
Before planting begins, farmers should perform a standard equipment check to make sure tractors, tillage and planters are in good working order. Checking oil, hoses and fittings is typically at the top of mind – but we can’t forget about tires. Firestone Ag has created a seven-step Tire Check list to help farmers quickly but effectively check their tires this off-season so they can maximize up-time when planting and growing seasons arrive.
The Firestone Ag Tire Check list provides seven steps that help to identify signs of tire wear. Regularly checking tires can help prevent and avoid more time-consuming problems in the field, therefore increasing the tires’ lifespan and a farmer’s profitability. After completing the 7-step list, if any abnormalities are found, a certified Firestone dealer can inspect the tire to know if repairing or replacing the tire is the best option for the farmer.
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.