Understanding the Anatomy of a Tire

Bridgestone Team 

It's important to get to know the basic anatomy of agricultural tires—including each of the tire’s components—so you can see how tire construction shapes performance. With this knowledge, you’ll better understand the role each part plays in helping your farm’s tires deliver when you’re in the field for soil prep, planting, spraying, or harvest.

Read on for everything you need to know about the anatomy of your tires.

Let’s take a closer look of an Ag tire
1. Bead

Beads anchor the tire to the rim and allow the tire to stay "seated" on the wheel.

2. Bead filter

Bead fillers stabilize the lower sidewall by enveloping the bead and extending up into the sidewall to maximize stability, steering response, and case durability.

3. Innerliner

Liners protect the cord body by insulating the tubes from the cords. Liners are essential for resisting air and moisture permeation.

4. Belts

Belts determine the shape, or footprint, of the tire. Belts work together with the cords to add stability and strength.

5. Tread design

Treads engage with the soil or paved surface to provide traction. Tread design varies between tires to help maximize grip and resist wear and tear.

6. Sidewall

Sidewalls consist of flexible rubber and add lateral stability. They protect the body plies and inner liner from stubble and debris. Sidewall flex is a key factor in choosing the right tire for your job or equipment.

7. Lug Butters

Lug depth is important for traction. Along with the lug buttress, it helps keep your treads stable.

8. Body Plies

Cords run radially from bead to bead, setting the strength and load capacity of the tire, and providing lateral stability.

Bias vs. radial: which is best?

Bias ply tires use multiple plies of rubber crisscrossed over one another, connecting the sidewall and tread. Radial tires, on the other hand, are built in two separate parts: the body plies run perpendicular to the bead and steel belts circle under the tread. This design means sidewall movement isn’t transferred into the tread, so radials help reduce soil compaction.

Bias tires are a great fit for forestry or non-tillage equipment and usually cost less than radials. Radials give you a broader footprint for better traction, lower soil compaction, and improved fuel efficiency. For more guidance, connect with a certified Firestone Ag Dealer to find the right tire for your needs.

Bias tires – a cost-effective solution

Bias tires are perfect for smaller, lightweight production equipment that requires extra stability for non-tillage work.

  • Stiff sidewalls help with forestry work and cut resistance

  • Crisscross body plies create internal friction that create stability but run hot

  • Cost effective options for older or lightweight equipment

  • Best when you need protection against sidewall punctures

  • Not recommended for everyday tillage or production

Radial tires – dependable fuel economy

More traction means better fuel economy and helps you cover more ground. Radial tires can last up to 30% longer than bias tires, and radial options with AD2 technology let you carry more weight at lower inflation pressure.

  • Shows an advantage of 6% to 14% in traction, fuel economy and reduced wheel slippage over bias tires. 

  • Bigger footprint, longer tread wear and a smoother ride.

  • More resistant to tread cuts and punctures.

  • Typically easier to repair

  • Runs cooler over long days

  • Ideal for larger equipment

AD2 tires have a larger footprint that can help improve the productivity of today's heavier equipment with less time in the field and reduced fuel consumption. They can help you carry the same loads at lower pressure, reduce soil compaction, and improved traction.

How to understand tire size

When choosing the right tire size for your tractor and your farm’s traction needs, you will be looking at a set of numbers on the sidewall of your tire for guidance.

  • Tire width

  • Aspect ratio

  • Radial (if applicable)

  • Tire diameter

For a deeper dive into these measurements and choosing your tires, check out our How to Read a Tire Guide



Making sense of tread patterns

R-1 – Regular Agriculture: aggressive patters that deliver traction in most common soil conditions – it’s also the standard tread for dry-land farming.

R-1W – Premium Tread Agriculture: built for wet or sticky soil types. R-1W lugs are up to 20% deeper than on an R-1, so you get extra grip where you need it.

R-2 – Wet Farming Applications: made for super wet conditions, with treads that are twice as deep as an R-1 and more space between lugs for wet or flooded fields. Typical applications are rice, sugar cane and high-value vegetable crops.

R-3 – Shallow Industrial: R-3 is a non-aggressive pattern for minimal ground disturbance sites like airports, gold courses, cemeteries or roadside maintenance. Its relatively closed tread pattern is designed to evenly distribute the load on maintenance trailers and grain carts.

R-4 – Construction & Light Industrial: R-4 tires are intended to be operated on hard surfaces with backhoes and small loaders, with a tread depth approximately 70% of the R1 tread.

Find the right tire

There are many tires to choose from, but finding the right tire for your needs is simple with our Tire Selector tool.

What others are reading



Solutions for you