What are radial tyres?
Updated 19 Feb 2021
Radial tyres are the most commonly used structure of tyre today. As passenger cars changed and the needs of customers changed, the previously used and now outdated bias structure of tyre was no longer up to scratch.
The first radial car tyre was commercialised in 1948 by Michelin in France and by the time the 1960s had come to an end, the radial tyre had reached the rest of Europe and Asia.
Radial tyres get their name due to the way they are constructed. The internal structure of the tyre sees cable plies radiate around the axis of the tyre, in addition to another ‘belt’ of plies forming the structure for the crown, or top, of the tyre. Plies are essentially layers of various materials within a tyre, with the number of layers and plies changing depending on how the manufacturer intends the tyre to be used.
This construction of radial tyres allows them to retain rigidity on the surface whilst having a great range of flexibility in the sidewall. This flexibility means radial tyres are better suited to powerful vehicles with rigid chassis and are able to handle high speeds better than a bias tyre.
Radial tyres also provide improved grip when going around corners due to their wider track under load. Another benefit of radial tyres and their flexible sidewalls is that they are better at handling imperfections in the road as the tyre works to absorb the bumps and knocks that would otherwise be transferred throughout the car.
In terms of tyre life, radial tyres again get the upper hand. Pressure in the contact area of a radial tyre is more evenly distributed than with a bias tyre. This means that radial tyres achieve more consistent wear.
Other general improvements that the radial tyres have over the bias tyre include longer tread life, improved steering and handling and less rolling resistance, which all translates to better fuel economy.
Although bias tyres are still used today in very specific circumstances, chances are your passenger vehicle will be fitted with radial tyres.
On weekdays Rowan can be found in the AutoGuru office, driving content and growth with the rest of the marketing team.
On weekends you’ll probably find him in the garage with his father restoring a 1958 Ford Star Model Customline or enjoying a cruise through the Gold Coast hinterland on his Suzuki GSX-R600.
Despite his passion for being behind the wheel (or handlebars), he looks forward to the day when he can commute to work in his own driverless car.