Pirelli Cinturato

The Pirelli Cinturato is a Pirelli-developed car tyre that was the first example of a wrap-around radial tyre structure. It was used to good effect in motorsport, and most modern tyres are based upon the design. The five-times Formula One World Champion Juan Manuel Fangio called the Pirelli Cinturato "Extraordinary" and raced on it many times in the remainder of his career.

First developed in 1952 under the name Pirelli Cintura, taking the name Cinturato in 1963, the tyre was composed of two or three carcass plies of cords laid at an angle of 90 degrees to the beads, and a belt of several plies laid circumferentially under the tread. Without a belt, the 90-degree plies would produce a casing which would greatly increase its sectional height on inflation. The belt, being inextensible, prevented the casing increasing in height when inflated, and the inflated tyre maintained almost the same dimensions as in the mould in which it went through vulcanisation. The belt was kept under tension, and the tread retained its flatter profile even when the tyre was inflated.

The Pirelli Cinturato may be compared to a wheel in which the rim is attached to the hub by means of fine spokes. The tread and belt are in effect the rim; the 90-degree or radial cord plies are the spokes; and the bead is the hub. The inextensible belt and the radial casing cords were the combined factors which gave the Cinturato tyre its special properties. The different geometric arrangement of the Cinturato carcass resulted in greater deformation (bulging) in the area of the tyre section which is under load, as opposed to previous radial tyres of the period. This caused no disadvantage and did not result in greater tyre casing fatigue. Rather than having the dynamic wave form behind the road contact area, it instead formed on the side wall, increasing stability whilst also allowing the heat generated by cornering and braking to be easily dispersed.

During the 1950s, 1960s and 1970s the Pirelli Cinturato was the original equipment tyre for many exotic Italian cars including Lamborghini, Lancia, Alfa Romeo, Maserati, Ferrari as well as for cars produced by other manufacturers worldwide, including MG, Rover Group, Volvo and Lotus Cars. Many other international car manufacturers such as Jaguar and Aston Martin that were still fitting crossply tyres as standard equipment fitted Pirelli Cinturato as their radial upgrade for customers that could afford it. By the end of 1968 Pirelli was exporting or directly manufacturing the Cinturato to or in as many as 137 countries worldwide. In 2014, the Pirelli Cinturato P7 was developed, derived from F1 technology, which had permitted Valtteri Bottas to drive his F1 car at a maximum speed of 316 km/h in fog.

...
Wikipedia