X

The radial revolution

A revolutionary construction for unrivalled performance...

Thanks to its X tyre with radial casing plies, Michelin set out to conquer the world with a considerable advance in technology.

Its revolutionary construction for the time had the special feature of separating the sidewall function from the crown function.

Dimensions

Dimension Seat Sculpture TT/TL Load Index Speed Code Section width (mm) Outside diameter Circ. bearing Rim width (mini-maxi) Tube
7.25 R 13 13'' X TT 90 S 180 654 1988 5.0 5.5 6.0 13 F 13
125 R 15 15'' X TL 68 S 127 598 1818 3.0 3.5 4.0 15 CB 13
125 R 400 400mm X TT 69 S 130 619 1882 125 135 16 C 13
135 R 400 400mm X TT 73 S 138 631 1918 125 135 145 16 C 13
145 R 400 400mm X TT 79 S 142 649 1973 145 155 16 E 13
155 R 400 400mm X TT 83 S 150 660 2006 145 155 165 16 E 13
165 R 400 400mm X TT 87 S 162 677 2059 155 165 185 16 F RET
185 R 400 400mm X TT 91 S 185 707 2149 165 185 16 F RET
5.50 R 16 16'' X TT 84 H 172 690 2088 4.5 5.0 6.0 16 F RET
185 R 16 16'' X TT 92 S 180 707 2139 4.5 5.5 6.0 16 F RET

Technical informations

Radial technology

The benefits of the radial tyre compared with the standard tyre were visible in all areas:

- greater safety: clearly improved road-holding, grip, braking.

- economical to use: double the mileage, significantly reduced fuel consumption.

- increased comfort thanks to sidewall flexibility.

In the 1950s, the superiority of the X tyre was such that a number of racing drivers adopted it, although Michelin was not officially involved in car racing.

Related links

The adventure of

X

Michelin innovation

The radial tyre was the first major innovation from Michelin and was initially marketed as the “X” tyre in 1949.

Lancia was the first car manufacturer to fit the X tyre as original equipment on the Aurelia model.

From 1955 onwards, radial technology became increasingly popular and the majority of European car manufacturers opted for this solution.

The X could be fitted to cars of very different categories, from the original and popular 2CV or Beetle to the fascinating Mercedes 190SL or Facel Vega.

1949

Launched in

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