Standard tire sizes are the easiest of the two measurements to read. An example is “16, 9 — 30. Here, “16, 9” indicates the tire width in inches and “30” indicates that the tire will fit a 30 inch diameter wheel. An example of tractor tire sizes expressed in the standard format would be “14.9-42”.
The “14.9” means that the tire is 14.9 inches wide and the “42” indicates that this tire fits a 42 inch diameter wheel. The hyphen “: indicates that the construction of the tire has a skewed layer, but could be an “R” if the tire is radial. This example is actually the size of the tire I have on the back of my 4×4 diesel tractor. For the diameter of the tire, you must measure the circumference at the center line of the tire.
The easiest way to measure this distance is to use a chain. Secure the end of the rope at the starting point and wrap it around the tire. Mark the chain where it crosses the starting point. Now measure the length of the rope, which will be the circumference of the tire.
Divide the circumference measurement by 3.14 and that value is the diameter of the tire. The tire numbering system for lawn tractors with three numbers works in a. The first number before the “x” indicates the diameter of the tire when it is inflated and not under load. The middle number between the “x” and the “-” indicates the width of the tire.
The final number indicates the width of the tire. Please note that the last number is the width, not the diameter of the tire. This is always the case with the three-number sizing for lawn tractor tires and other tires for garden equipment. Let's talk about numbers, you'll probably see two sets of numbers.
The first number you'll notice is the width of the tire from one sidewall to the other. The width determines the buoyancy; the wider the tire, the more likely it is to have better traction on textured terrain, for example, on muddy dirt and sand. The second number is the diameter of the tire, which indicates whether a tire fits a tire of a certain size. If you see three numbers, the first number will be the height of the tire, followed by its width and tire diameter.
Consult your tractor manufacturer for guidance if you have questions about the different tire size compatibilities and how they affect the operation of the tractor. Even the best tractor for small farms can be useless with the wrong tire installed, so care must be taken when choosing the tire size to fit your tractor. Positive offset occurs when the hub mounting surface is more oriented toward the outside of the wheel, causing more of the wheel to be closer to the tractor. Since getting the right size of agricultural tractor tires is critical to the performance of your tractor, if you don't yet know where to start or have questions for help, you can always talk to a professional at any FIRESTONE AG CERTIFIED DEALER.
Tractors and implements require specific tire sizes, constructions and tread patterns to continue to operate at maximum efficiency. As if the gibberish wasn't cryptic enough, there are actually two ways manufacturers can express the size of their tractor tires. Depending on the tire manufacturer and application, almost all tire sizes are usually indicated in standard or metric sizes. This will likely determine if you're going to buy a premium brand or if it's better suited to a cheap tractor tire made in China.
The second step in choosing parts for your worn tires is to understand your options and adapt them to your needs, since what your tractor comes from the factory may not be the best tire to do what you need today. Now that you have the measurements of the width and diameter of the wheels, the measurements of the screw pattern and the offset of the wheels, you are ready to confidently buy the right wheels and tire for your tractor, equipment or trailer. Once again, a measuring tape or ruler will continue to work and give us a close enough approximation of the size of the holes so that we can identify the correct pattern. Negative offset occurs when the hub mounting surface faces the inside (or side of the hub) of the wheels, resulting in a greater part of the wheel at a greater distance from the hub or tractor.
When you're thinking about how to measure the tires and rims of a tractor, it's also important to check the inside of the heel fringe, as many manufacturers indicate the tire size there. More importantly, most modern farm tractors are 4×4, and changing this size ratio can destroy your gear train. . .