Understanding Tyres and Types part 2– Tyre Tread Type
Published On 25-Oct-2017
As important as it is for you to understand the types of tyres and their properties, it is important for you to understand the tread types too. A variety of road and weather conditions necessitate the use of different treads on tyres. The same tyres which are used in dry conditions will also be used when it rains or while negotiating your way through a gravel-laden path. So, here we present to you the various tread types that can be seen on tyres today, along with their purpose:
- Unidirectional Tread Type
[caption id="attachment_3822" align="alignnone" width="500"]
Motorcycle tyres always sport unidirectional tread type.[/caption]
Unidirectional tread type aims to establish a simple concept - a tyre can not be used outside of its limitations. In this case, a unidirectional tread type tyre cannot be used on the left side of the car when it is meant for the right side (and vice-versa). This is done to ensure a few things – (a) tyre rotation becomes a careful practice as rotation can happen from front to rear axle and vice-versa, not from left to right; (b) you always take care of how the tyre is mounted as the tread direction determines the rolling direction of the rubber, and; (c) the effects of hydroplaning can be minimised. The last part is the reason why unidirectional tyres are used for wet-surface applications more specifically than any other type.
- Symmetrical Tread Type
Symmetrical tread pattern is almost every major car makers' favourite type of tread pattern. Symmetrical tread pattern tyre have same tread pattern throughout their surface. This ensures that there are no limitations when it comes to tyre rotation. Since the construction material stays the same throughout the tyre, this tread pattern type serves well for all-purpose usage but fails when put to a dedicated use, say racing.
- Asymmetrical Tread Type
Asymmetrical tread is a type which is meant to give different qualities to a tyre. This is done by using different compounds for different tread types on the tyre. This ensures that if a tyre needs to offer high levels of grip on dry and wet surfaces, such properties can be engineered into the tyre. Usually, large tread blocks are used on the outside of the tyre to offer maximum stability as the car corners while the small blocks on the inner portion minimise the effects of aquaplaning. Since these tyres combine various qualities, they are also costlier than their symmetrical tread type counterparts and are limited to performance car applications.
- Unidirectional/Asymmetrical Tread Type
Unidirectional/Asymmetrical tread type combines the best qualities of both the unidirectional and asymmetrical tread types. This tread type bestows best of dry and wet weather handling capabilities on the tyre. However, tyres with such a tread type face the same restrictions of tyre rotation as those on unidirectional kind i.e. they can be switched from front to rear axle and vice-versa but not from left side to right side. Tyres sporting this type of tread are costlier than their asymmetrical counterparts too, owing to their capabilities.
So, these are the tread types used on tyres made today. Except symmetrical, all other tread types ensure limited tyre rotation abilities and hence, call for caution. Thus, always check the sizes of all tyres on your car. If your car wears different size tyres on rear than those on front, the tyre rotation possibilities become even more limited (in the case of asymmetrical type, side to side; in the case of unidirectional type, no possibility of tyre rotation).