If you go tractor shopping, you soon find out there are a bunch of choices to make. Even among tractors of the same manufacturer, you need to know what your present needs are and what your future needs might be to select the best tractor for your operation.
The same goes for shopping for new tires for your tractor. What brands are best? What size tires should I use – an exact replacement or smaller/larger? Should I go with bias ply tires or the generally more expensive radials? Your selection might even affect where you buy your tires and who mounts them based on local availability.
So what is the best choice? I hate to continue to use the old lawyer phrase, but “it depends” is the most correct answer. Given that fact, we can still walk through a few discussion points and help you on your quest for your tractor’s “new shoes.”
First, where do you farm? That might seem like an odd question, but tire sizes, tread styles and construction types are determined a good deal by where they are being used. Sandy or wet soils require a different tread type on both the front and rear of the tractor.
For example, rice farming may call for a single-rib front tire (on two-wheel-drive models, of course) and an extra deep lug to deal with the wetter soils. If you are new to farming or new to the area, it might be wise to discuss tires with your neighbors and see what tires they are running successfully or otherwise.
Second, how spread out is your operation? Running tractors on pavement for long distances is hard on tractor tire treads. It has been my experience radials hold up better in applications where a lot of roadwork is required. The extra life given by the radial designs makes up for the added expense of the higher purchase price in a hurry when you use your tractors over the road.
Third, what crops are you farming? Soil compaction is a major contributor to lower crop productivity in many fields across the U.S. A wider and longer “footprint” under your tractor may be needed to help reduce soil compaction, especially in wet conditions or in crops that are either more susceptible to compaction issues (such as alfalfa) or among crops that require more frequent trips across the field, such as silage corn supplemented by manure applications.
Next, what is the main “job” of the tractor in question? As we just mentioned, crops can play a huge role in deciding which tires are best, but there are different applications within the same cropping system. For example, a high-flotation tire will be very desirable in a cornfield; however, that same tire will make the chore of packing the bunker silo being filled from that same field much more difficult.
In the silo, we are looking to apply as much pressure per square inch as we possibly can – just the opposite of our work in the field. Of course, the way a tractor is balanced and ballasted plays a major role as well, but that is a topic for another article.
How much horsepower is your tractor capable of making? My wife will swear to you I always gravitate to the “bigger is better” and “more expensive is better” camps. Frankly, I haven’t done a lot to dispel this myth. But there are times when putting $5,000 into the tires of a tractor worth $4,500 just doesn’t make sense.
A well-designed bias ply tire is just fine for some of my smaller tractors that just don’t have the power or ability requiring a more expensive radial tire to apply a better grip. I also have an antique tractor or two that require special tires to retain their nostalgic look. These tires are also not built for tough pulls and roadwork; however, that apparently is not a determining factor in the price of these specialty tires.
While we generally think about the rear tires of tractors because of their size and expense, the front tires also need to be considered for functionality. One very important consideration in mechanical front-wheel-drive and four-wheel-drive tractors is matching tires up all around the tractor.
Just like a four-wheel-drive pickup, front-wheel-assist and four-wheel-drive tractors have lead-lag ratios that allow tires to work in concert when power is applied. Fiddling with different-sized tires or different tire configurations can cause the rears to “push” the front tires or the front tires to “drag” the rear. Either way, excessive and unnecessary tire wear will result, and powertrain damage is a real possibility.
Front tire tread design is also a factor. Some brands will alter the front tread patterns slightly with great effect on performance. The cleats of the tires may be curved outward as they approach the center of the tire to provide a degree of steering assistance.
These tires often carry a moniker that will identify them as specialty front tires for mechanical front-wheel-drive tractors. I have found they do a great job keeping the tractor “in line.”
When I was more actively farming, I had a tractor specially fitted for over-the-road work. I used step-up rims to increase the rear tire size from 34 inches to 38. I also used aircraft tires on its narrow front end to cut down on flats and give the tractor a more stable front footprint on pavement.
The result was a tractor with a higher top-end speed and the handling of a race car. While we are on the subject, step rims or fitting a larger hub and wheel on a tractor may cause issues with the hitch. A quick hitch may be needed to allow the three-point hitch to use an implement without it striking the rear tires.
The wheel and tire configurations listed above worked well for me on that particular tractor, but it certainly isn’t for everyone. Over the years, I was asked about the safety of that tractor, and my answer was that a tractor is only as safe as the person driving it.
Which brings us right back to the original “lawyer speak” answer. What tire is best for your tractor? It really depends on you. Walking your way through some of the previous questions will help, but in the end the decision is yours to make. Consider what is best for you, but please consider the safest way to operate your tractor. The most important – and only irreplaceable piece on the tractor – sits in the operator’s seat. 
Andy Overbay holds a Ph.D. in ag education and has more than 40 years of hands-on dairy and farming experience.
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Andy Overbay
- Extension Agent
- Virginia Cooperative Extension
- Email Andy Overbays
