By Tire Agent Staff
January 07, 2022
Tire treads have four basic parts: the ribs, the grooves, the tread blocks, and the sipes. These tread patterns aren't just there for looks; they each have their own purpose, which we will explain as you read on. We'll also explain what the three basic types of tread patterns are for, which will help you decide what's best for your vehicle.
And, who knows, this knowledge might even make you a little more interesting at parties, as long as you don't go on too long about it.
If you'd prefer not to nerd out over tire tread anatomy and want to get straight to shopping, don't let us get in the way. Click "Shop New Tires Now" to get started. Otherwise, Tread Nerds, scroll on to read about ribs, grooves, blocks, and sipes.
As fans of true-crime TV and podcasts know, tire tread patterns have been key to solving many crimes. Vehicles leave their own "fingerprints" in the form of tire tracks, not only revealing the make and model of the tire but also helping detectives narrow to the make and model of suspicious vehicles.
But that's not why you're here. You're here to learn tire tread lingo. First up, let's define these four tire parts.
What are tread blocks? These are the raised parts of the tire that make contact with the road. The block provides traction.
Tire ribs are the raised section of the surface of the tire, a collection of tread blocks. What do tire ribs do? Well, think about the job of a tire: A vehicle tire must ...
This is the job of the tire tread, and the rib plays a significant role in vehicle stability.
Tire grooves are the deep channels between the ribs and tread blocks. They have an important job, especially in rain, snow, ice, slush, and mud. The grooves are designed to push those elements away from the car so the tires grip the road better. So, the next time you're a pedestrian and you get splashed by a car? That's the grooves at work.
Sipes are thin "cuts" that are molded into the blocks. Unlike grooves, which run the circumference of the tire, sipes are smaller and thinner grooves that provide more flexibility in tires. You want sipes in on- and off-road tires, loose dirt and gravel and, of course, ice and snow.
So, put ribs, blocks, grooves and sipes together and you've got your tread pattern. Most patterns fall into one of three categories: symmetrical, asymmetrical, and directional. There's also a less common directional/asymmetrical pattern, which is found in ultra-high-performance tires.
Asymmetrical tread patterns have two distinct tread patterns: an inner pattern and an outer pattern. The inner pattern is all about handling in wet conditions and preventing a vehicle from hydroplaning. The outer pattern is all about grip, especially on curves and corners. This type of tire is popular on high-performance vehicles.
An example of the asymmetrical tread pattern is in Toyo's Celsius CUV for SUVs and light trucks. The asymmetrical design offers steady grip and handling in wet or dry driving conditions.
You have to be careful when rotating asymmetrical tires; follow the manufacturers' recommendations. Tires with asymmetrical tread patterns typically have "this side out" on the sidewall of the tire that always must be facing out of the vehicle. Do only front-to-back and vice versa rotations.
A Symmetrical tread pattern has the same patterns on the inside and outside blocks of the tires.
Symmetrical tread patterns provide the smoothest driving experiences. This is the most common type of tread pattern. Both halves of the tire have the same pattern. They also tend to offer the quietest rides, low rolling resistance, and best fuel efficiency.
They are ideal for most passenger vehicles, but not necessarily for high-performance vehicles, and symmetrical tread patterns aren't usually found on all-weather or winter tires. If you're looking for an economical tire that will last a long time, choose one with a symmetrical tire pattern. These tires can be rotated several times, which extends the life of the tires.
Kumho ECO Solus KL21 has a symmetrical tread pattern -- no matter which way you turn the wheel, the pattern is the same.
Directional tire patterns are designed to make sure the tire rolls in one direction. That doesn't mean you can't back up a vehicle on the tire. It simply means that the treads are designed to move a vehicle forward, especially through snow and wet conditions. Many winter tires have directional tread patterns. What this means, though, is that you can't rotate directional tires from side to side; you can, however, rotate them front to back and vice versa.
You can see an example of the directional tread pattern in Lionhart's LH-503 all-season tires.
We mentioned the less-common directional asymmetrical tire tread pattern. It's an uncommon tire pattern, and tires with these patterns are only left or right-side vehicles. They cannot be rotated from the driver side to the passenger side or vice versa. These types of treads are found on competition tires, as well as ultra-high performance tires.