Have you ever paid attention to your tyre? Besides having a general idea that they are black and round, have you really looked at your tyres? If you have, you may have noticed that your tyres have a certain pattern on their surface. This pattern is called the tyre tread pattern. The tyre tread pattern influences tyre performance to a large extent.
The Tyre Tread and the Tyre Tread Pattern
The tyre tread is the rubber on the surface of the tyre. It is the portion of the tyre that directly comes in contact with the road. Thus the main function of the tyre tread is to provide grip and keep the vehicle stable. But the tread, which is a smooth band of rubber, cannot provide any grip by itself. Hence patterns are cut into it for grip. And this is nothing but the tread pattern.
Besides, riding surfaces may vary greatly, containing mud, snow, ice, water, off road, smooth pavement etc. So the tyre tread is moulded into a specific pattern, making the tyre suitable for that particular surface. And hence we have different types of tread patterns for different types of tyres.
Basic Tyre Tread Patterns & Their Functions
Symmetric Tread Pattern
As the name indicates these tyres display an identical tread pattern on either side of the central tyre rib. It features continuous ribs or independent tread blocks in the same arrangement along the entire circumference of the tyre. Symmetric tyres are quite popular in passenger cars and provide a good balance between wet and dry traction, while maintaining steering responsiveness.
Asymmetric Tread Pattern
One of the most popular tread patterns in passenger cars, this pattern is designed to optimise grip on both wet and dry surfaces, without one compromising the other. In this tread pattern, the outer tyre shoulder exhibits large and wide compact tread blocks that increase the contact patch on dry roads, resulting in better handling and increased steering responsiveness.
The inner tyre shoulder has smaller independent tread blocks (similar to the symmetric tread pattern) with numerous longitudinal and transverse channels (also called sipes). The purpose of these channels is to evacuate the surface water lodged in the tread. Thus the contact patch between the surface and the tyre increases, resulting in increased resistance to aquaplaning and better wet handling characteristics.
Directional Tread Pattern
Tyres with directional tread pattern have unique V-shaped grooves that radiate outwards from the central tyre rib to either sides. Such tyres are particularly efficient in dispersing water when the vehicle is moving at high speeds and hence are suited for performance vehicles.
Snow/Mud Tread Pattern
The tread pattern for snow tyres is characterised by the presence of numerous sipes which provides biting edges. It also has tread blocks with deep and wide grooves which enhance the traction on snow.
Mud terrain tyre tread pattern has large chunky tread blocks that dig into the mud and offer increased grip. Also the large open design enables the tyres to self-clean, getting rid of mud stuck in between the lugs.
Snow/mud tyres are not recommended for regular surfaces as they have a reduced contact patch that compromises traction on these roads. Besides their particular tread pattern makes these tyres very noisy on normal roads.
This article has been written by Azzam Sheikh, tyre consultant at Tyre-Shopper UK.