Difference between Bias and Radial Tyres - TyreCafe
By Editor News ( Mar 29, 2019 )There are numerous factors that need to be looked upon while opting for the best-suited tyre for your bike or scooter. Durability, grip, control on a wet surface, cornering ability, tread capacity, cost are to name some. Tyre manufacturers have come up with different types of tyres like bias, radial, tube and tubeless to fulfil the requirements of different bikes and road conditions. It is important to understand the Difference and Features of Bias and Radial Tyres, as both of them are designed to serve a specific purpose.
There are huge disparities in the world of motorbikes and scooters. For different types of two-wheelers and road conditions, different types of tyres are required. To adapt to this wide variety of requirements, tyre manufacturers have come up with two types of tyre architecture- The bias or cross-ply structure and the radial structure.
The carcass of a bias tyre consists of diagonally oriented cable plies. The plies are stacked crosswise over the direction of the cables. The structure is uniform and the tyre crown and sidewalls have similar mechanical properties.
In a radial structure, the cables radiate around the axis of the tyre. In addition, the crown consists of plies forming a belt. The sidewalls and crown, therefore, have specific characteristics. These two structures generate different types of performance. In contact with the ground, thanks to more flexible sidewalls, a radial tyre provides good grip on the road. Its footprint is not as long as that of a bias tyre but is wider, offering more grip at a sharper angle when taking bends.
The pressure in the radial tyre contact area is more evenly distributed which ultimately means more uniform wear. Thanks once again to its flexible sidewalls, a radial tyre offers greater ride comfort at high speed by cushioning irregularities in the road surface.
A bias tyre, however, is better able to withstand a heavy load as its sidewalls are more rigid. At high speed, the profile of a bias tyre becomes deformed to the extent that it affects handling. A radial tyre, however, remains stable thanks to its crown belt with a continuous integrated cable around the circumference.
As we have seen the bias structure is suitable for vehicles travelling at a moderate speed with small or medium-sized engines and a reasonably flexible chassis. It is also suitable for heavy or heavily loaded bikes. The radial structure becomes a necessity for more powerful vehicles with an extremely rigid chassis and once used for sport. It enables speeds in excess of 150 miles per hour to be reached.
Let’s look at the key difference between bias and radial tyres:
- Speed - The bias structure is suitable for vehicles travelling at a moderate speed. The radial structure, however, enables speeds in excess of 150 miles per hour.
- Engine – Bias tyres are suitable for small or medium sized engines. Radial Tyres are used for comparatively powerful engines.
- Chassis – Bias structures is suitable for flexible chassis, whereas, the radial structure is suitable for rigid chassis.
- Suitable bike – Bias tyres are suitable for heavy or heavily loaded bikes. Radial tyres, however, are suitable for sports bikes.