Flotation is the name of the game when it comes to tire performance during harvest. Traction takes a back seat to flotation as farmers have to move massive combines across fields that can turn treacherous with late-season rains. How do you gain flotation? You give your machine a bigger footprint with bigger tires. Whenever farmers talk about increasing their combines’ flotation, the discussion always revolves around the fronts. But you can’t afford to forget your combine’s rear tires.
Larger is Generally Always Better
In any given year, a lot of farmers call NTS looking to upgrade their combine tires. (Sometimes at the last minute or in the middle of harvest.) The conversation usually goes something like this: “It’s wet, time is running out, and I need to get back in the field.” And in a bone dry year we hear, “How soon can you get a service truck out to me? I have a wheel cracked out again.”
Combines are heavier than ever, especially with chopping and folding heads and hopper extensions to boot. That’s why farmers are often looking to upsize their combines’ front tires. Up front, there are two directions to go: either switch to LSW super singles or go with wider duals. Both options supersize a combine’s footprint for significantly better performance in the mud and better durability too—no more cracked wheels bringing harvest to a halt.
Bigger is Better for Your Combine’s Rear Tires Too
For the best shot at a smooth harvest, you also have to pay attention to your combine’s rear tires. Here’s a common scenario we see:
- A farmer has struggled to keep harvest on track the last few years because his combine keeps sinking into the mud and getting stuck. So, he gives us a call and we switch his combine fronts over from 520 duals to 800 duals.
- The farmer’s combine now has much better flotation up front, but still struggles to cross those wet spots because the combine’s rear tires aren’t sized to match the new front setup.
It’s not only the front of a combine that’s heavy. A combine’s rear might not tip the scale when compared to the front end, but it will sink just as well into soft, muddy soil and contribute to high levels of soil compaction. So you have to pay attention to the rubber on your combine’s rear to totally optimize its footprint.
Our Top Combine Rear Tire Size Recommendations
Whether a farmer decides to upgrade his combine’s front tires to wide duals (800/70R38 for example) or LSW super singles (1400/30R46 for example), the combine’s rear tires should also be swapped out. A 750-width tire (750/60R30 for example) should be the bare minimum rear tire for today’s largest combines.
Larger rear tires on your combine improves the machine’s overall footprint and avoids the common pitfall of the combine’s front floating over a wet spot only to find that the rear still sinks in. And since most combines now have rear wheel assist, you’re getting an important boost in traction as well with a larger rear tire size.
So which do you choose for your combine? Talk to one of our tire experts and we’ll guide you to the best choice for your needs based on your combine class and front tire/track setup.
Go CFO and Avoid Bias Tires at All Costs
Why shop for CFO-rated combine rears? CFO tires can better support your combine’s weight because they can temporarily carry 55% more load than standard radial tires (under 10 miles per hour and for 1 mile at a time).
Read More: CFO Tires Keep Your Harvest from Sinking
Every CFO-rated is based on an IF- or VF-rated radial design. These are tires that are designed to carry higher loads at lower air pressures. Remember that, in the field, you want your tires’ pressures as low as possible to prevent sinking, rutting, and deep soil compaction. Over time, compaction has the nasty side effect of decreasing your yields. So it pays to steer clear of it by running at the lowest safe tire pressure in the field. IF and VF tires will get you there.
Whatever you do, ditch those old bias-ply tires. Yes, even on your combine’s rear. A bias tire’s small footprint is harder on your soil and is much more likely to leave you stuck—either in the mud or with a sudden tire failure. For your farm’s largest machines, your combine included, radial is the only sensible way to go.
Mount Rear Tires Backward or Forward?
Is the old practice of mounting combine rear tires backward a good or bad idea? It’s probably better to mount them forward. That said, when installing combine rears on customers’ machines, we at NTS generally defer to each customer’s wishes.
Originally, combine rear tires were mounted backward to provide a smoother ride and better mud cleanout. And, with more combines becoming equipped with rear-wheel assist, some farmers felt that the backward-mounted rears would give them better traction if they had to back out of a wet spot. However, there are two reasons why it’s better to mount your combine rear tires forward:
- When moving forward with the rear tires mounted backward, the lugs will be directing all of the stubble toward the tire’s center. This raises the risk of a puncture and will eat up the tire faster from wear and tear.
- With rear-wheel assist, you’ll want the tread facing forward anyway so your rear tires can provide optimum traction to help move the combine across the field.
Set Your Combine Up for Success with the Right Tires
It isn’t hard to properly set up your combine for maximum flotation and harvest uptime. Simply call NTS Tire Supply and talk to one of our tire experts. We’ve helped farmers and equipment dealers set up hundreds of combines and we can help you optimize your combine’s front and rear tire setups too. Why invest in an aftermarket tire/wheel setup for your combine? Fewer (or no) deep ruts. Less calls for a tow strap. And no tire or wheel failures to clog up harvest. We’re here to help you Drive Your Farm Forward.