How Michelin's 1946 radial tyre patent changed tyre construction — a brief, factual history.
Most drivers have never given radial construction a second thought, but it's the reason modern tyres perform the way they do. Here's a brief, factual look at where it came from.
On 4 June 1946, Michelin registered a patent in Paris for a new tyre construction method: the steel-belted radial. The patent was filed in the name of Pierre-Marcel Bourdon, Michelin's Technical Director at the time. It was a significant departure from the cross-ply tyres that dominated the market, and it took a few more years of development before it reached the public.
In a cross-ply tyre, the internal plies run diagonally and overlap each other, which means the tread and sidewalls flex together rather than independently. A radial tyre's plies run straight across, at roughly right angles to the direction of travel, with a stabilising steel belt beneath the tread. This lets the sidewalls flex without disturbing the tread's contact with the road — improving grip, comfort and tyre life compared with the cross-ply designs of the time.
The radial tyre, badged the Michelin X, made its public debut around 1948–1949. From there, radial construction gradually became the industry standard, and other manufacturers developed their own radial designs over the following decades.
The basic radial principle from that 1946 patent — independent flex between tread and sidewall — is still what's under the tread of modern car and van tyres. It's a reminder that a lot of what keeps modern driving safe and comfortable comes down to engineering most drivers never think about.
