Do I need to start shopping for new tires? Tread wear, especially on rear tires, is blatantly obvious every time we climb aboard the machine. But what about the rims? Like every other part of a tractor, rims can and will wear out, so is now the time for a change?
There are times when changing the “shoes” on our tractor requires a rim change as well. Take our old picking tractor as an example. Yes, I know that using a mounted corn picker puts us about 60 years behind the times, but at some point, you decide to go with what you have until the opportunity for more profit outweighs the total cost of change.
The issue with the tractor that operated the mounted corn picker was that it continued to run the original 18.4-by-34 tires as it came from the factory 18 years prior, and because they were worn out, the 34-inch tires were too short.
If you weren’t careful crossing any ditch or uneven ground, the rear end of the picker (especially if we had the husker unit on for ear corn) could smack the ground and beach the tractor. And since it had the picker on, places to hook a chain that could withstand the power needed to drag the tractor free were limited.
When we lost the clutch prior to the 1992 corn harvest, we concluded that the time to upgrade the tires and the rims was right. We could have changed everything from the axles out, but the cast center rims were in great shape (and expensive), so they stayed.
A new set of 18.4-by-38 radials showed up at the farm as well as a set of double bevel rims that allowed the 38-inch tires to fit the 34-inch center hubs. What a difference.
The trouble with rear of the picker beaching? Gone! The drawbar was raised nearly a foot. The radials were like bolting on 50 extra horses. The tires with those special rims transformed our old tractor.
Out can require a rim change as much as up. Putting wider, flotation tires on your tractor will likely require a rim change as well. Putting a “too wide” tire on a “too narrow” rim will cause the new tire to “round up” and ride on the very center of the tread, instead of letting the tread set flat on the ground for maximum pulling leverage.
Another consideration that we discuss a good bit in my job as an animal science extension agent is the tractor’s track through the field. How much a tractor can straddle comes into play, especially when mowing hay.
Most of my producers would use a mower/conditioner to cut their hay crops and, if that is the case, we advise clients to set the discharge of their mower to leave a swath width equal to 80% of the mowing width. In other words, a 10-foot, 4-inch cutterhead needs to leave a swath of just over 99 inches. Why?
Light exposure. If you pile the newly cut hay up in a nice tight windrow, a large portion of the crop is shaded, if not completely in the dark. This slows drying time down greatly.
That said, the average width of a standard utility tractor is around 75 inches, but they can range from 70 to 83 inches in width. A 99-inch swath means you are running over your hay at every pass.
As much as possible, you need to configure your hubs, rims and tires to match the output of your equipment, especially in valuable hay crops.
But let’s say that you aren’t using this particular tractor in hay; you just want it to be as stout and stable as possible. When selecting new rims for this machine, it is best to consider several factors.
First, what is the capacity of the rim? The load capacity of the rim is crucial to prevent overloading, which can lead to premature failure and safety concerns.
Next, match the size of the rims to the size of the tires you need. Finally, the rims should be able to deal with whatever you throw at them. They should be able to withstand moisture, chemicals and fertilizer.
Outside influences aren’t the only stress on your tractor’s rims. Some fluid suspensions used for ballast can be very corrosive to the metals used in ag rims. You will see this especially around the valve stem.
The rim is an essential element in that it bears the weight of your tractor and transmits engine torque to the tire, and then to the ground. It must be proportionally sized and take into account the weight of your tractor with its implements and your engine power. If not, there is a risk that the rim may break.
Tractor rims come in many shapes and configurations; however, most fall into three main types: the W rim, the DW and the TW rim.
The single well shaped rim, W: This is an old model which is starting to be replaced by the double well shaped rim for large or medium-sized tires because for the W model, the mounting of the second bead wire is more difficult. This model is less resistant than the more recent designs. However, the W rim is still suitable for small-sized rims, for which there are no DW or TW models on the market.
The double well shaped rim, DW: This design is the most used at present because it is more robust than the W model and is easier to use during mounting and setting up operations. It allows more possibilities for the disc.
The TW shape is a design that is growing in popularity; it offers extra structural resistance, and its shape makes mounting easier as the tire slides more progressively over the three steps when putting the bead in place.
In the end, knowing your needs and what your tractor is capable of will point you to the rims you need to best fit your operation. Keep an open mind and take the time to consider every possible scenario. Then, your choice will be clear.
-(1).webp?height=auto&t=1780520834&width=285 "63549-pearce-Relatively-speaking---is-it-RFV-or-RFQ---field-sticks---IMG_3094-(Yoana-N)-(1).jpg")
