Tires are incredibly complicated components of automotive design, allowing for a variety of driving demands from daily commutes to 200 mph bumper to bumper racing. A vehicle simply cannot travel safely without tires, and one of the crucial pieces of tire safety and capability is the tire tread. Anyone who has ever looked at a tire is likely well aware that tire tread differs from one tire model to the next, but few realize the importance of tire tread or how and why it varies. Beyond adding an intriguing look to a tire design, tire tread also serves as a critical role in automotive safety.
What is Tire Tread?
Many think of tire tread as the knobs or shapes that can be easily seen on the part of the tire that comes in contact with the road. Tire tread actually consists of several components including, the shape of the tire, the tread blocks (also known as tread lugs), the tread grooves, tread voids, wear bar, and any extra features such as a rain grooves and sipes. Tire tread isn't a singular piece, but the whole of the tire that stretches from shoulder to shoulder where the tread meets the sidewall.
The tread blocks are most often referred to simply as the tread. Tread blocks are the chunks of rubber that protrude from the surface of the tire. They're the part that actually touches the road. Between them are the grooves and tread voids. Some of these tread lugs may have sipes in them which are small, narrow grooves cut into the blocks. Sipes can generally be found on tires meant for driving in wet weather and winter weather.They enhance the ability to quickly push water out from under the tire and increase stability by locking together under pressure caused by turning and braking. Some tread blocks also contain metal studs within siped tread lugs. These features are found in snow tires.
The spaces between the tread blocks are called the tread voids or tread grooves. Tread voids help give the tire its traction by acting in two ways. First, they allow the tread blocks to move and flex as the tire tries to grip the road. Additionally, tread voids also provide the space for which water can escape when roadways are wet. Many tires manufactured for wet weather climates possess a high tread to void ratio, which means there is a high number of voids compared to tread blocks. The result is improved wet traction and braking ability.
Within the tread voids, there are small units of measure known as wear bars, a small line of rubber on the side of the tread blocks. These can be seen within the treads of a new tire, but become more prominent as tire tread begins to wear. Once the tread lugs reach the wear bar, it is recommended that the tire or tires be replaced.
The Importance of Tire Tread
As briefly mentioned, tire tread does provide a tire its ability to grip the road. However, this statement only begins to describe the effect that tread has on performance. Vehicles and tires are engineered with a particular kind of performance in mind, and there is a variety of tread patterns and types that match each kind of intended performance. Ultimately, as vehicle manufacturers continue to up the ante in terms of automotive technology, tire manufacturers answer the call, offering tire tread that is able to meet a vehicle's performance potential. Tire tread is capable of allowing vehicles to corner tighter, accelerate smoother, and brake quickly. Tire tread is also capable of helping to maximize fuel economy.
One of the most obvious benefits of specialized tire tread is in the use of off-road vehicles. Everything from Jeeps to 4x4 trucks, as well as heavy machinery such as tractors use off-road, or all-terrain, tires. The tread is designed to work over any ground surface, whether rocky, wet, or covered in mud.