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"[1] and raced on it many times in the remainder of his career.

History

A cross comparison between a standard radial of the time and the Pirelli Cinturato

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.[2]

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.[3] 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.[4]

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 and Lotus Cars. By the end of 1968 Pirelli was exporting or directly manufacturing the Cinturato to or in as many as 137 countries worldwide.[5] 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.[6]

Cars that originally came with a Pirelli Cinturato option[7]
Tyre Size Cars
185VR16 CA67 Aston Martin 2-Litre Sports, Aston Martin DB2, Aston Martin DB2/4, Aston Martin DB Mark III, Aston Martin DB4, Aston Martin DB4 GT Zagato; Jaguar XK120, XK140, XK150 and C-Type; BMW 2500 and 375; 1950s and early 60s Maserati and Ferrari; Bristol up to the 409 in 1967; AC Ace; Triumph Gloria and Renown; Riley RM and Pathfinder; Lea Francis up to 1954; Daimler DB18
165HR14 CA67 Alfa Romeo Alfetta, Giulia & Spider; Audi 100; Austin Cambridge & A60 Countryman; BMW 1800 & 2000; Citroen GS; Lancia Flavia & Fulvia; Mazda 1800; MG MGB; MG Magnette; Morris Oxford; Peugeot 504; Porsche 924; Riley 4/68 & 4/72; Rover 2200TC; Wolsley 16/60
185VR15 CA67 Aston Martin DB4, DB5 and DB6; Jaguar E-type series 1 & 2 and Jaguar Mk1, Mk2 & S-type saloons; Daimler V8 saloon; Ferrari 250GT and 250GTE; Mercedes 220D; BMW 2600 and 3200; Citroen ID and DS; Morgan +8; Rover P4 and P5; Jensen CV8
155HR15 CA67 Alfa Romeo Giulietta and Giulia; Lancia Flavia and Appia; Lotus Elite; MG MGA; Peugeot 403 and 404; Triumph TR2 and TR3; Volkswagen Beetle
205VR15 CN72 AC 428; Aston Martin DB6 MkII; Aston Martin DBS; Bentley Type 1 (1966-1973); Ferrari 330 GT 2+2; Ferrari 500 Superfast; Ferrari 365 and Ferrari 365 GT 2+2; Bizzarrini Iso; Rivolta and Grifo; Lamborghini 350GT; Lamborghini 400GT; Lamborghini Islero; Lamborghini Miura and Lamborghini Espada, Maserati 4200 Quattroporte; Maserati Mistral 68; Maserati Mexico; Maserati Ghibli; Maserati Sebring; Rolls Royce Silver Shadow (1963-1973)

References

  1. ↑ "Juan Manuel Fangio Pirelli Cinturato advert". Pirelli. Retrieved 27 January 2014.
  2. ↑ Pattern of Progress, p. 2.
  3. ↑ Pattern of Progress, p. 3.
  4. ↑ Pattern of Progress, p.6.
  5. ↑ "History of the Pirelli Cinturato". Pirelli. Retrieved 27 January 2014.
  6. ↑ "Pirelli Cinturatto P7". VanzariAnvelope.net. Retrieved 2014-11-19.
  7. ↑ Fitment and pressure table for Cinturato car tyres, p. 3-8.

Bibliography

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External links