Michelin F1 Radial

It's brave move for a new player to change the rules of the game. On the eve of Michelin's return to F1, Keith Howard recalls how they transferred road technology to the track and altered the technical baseline for good.

French tyre giant Michelin took an inordinately long time to add their name to the long roster of Formula One tyre suppliers, which already included Continental, Goodyear, Engelbert, Dunlop, Firestone and Pirelli. But when they finally came to the party in 1977, they brought something radical, or rather, radial. With crossply tyres still the norm in grand prix racing, Michelin were about to re-enact the revolution which had already swept through the road tyre market during the 1960s.

When it departed F1 at the end of the 1984 season, Michelin had notched up 59 wins, three drivers' titles and two constructors' titles, and reckoned they had made their point. Indeed they had: Goodyear, which had enjoyed a monopoly in Fl before the arrival of Michelin and then Pirelli, held out against the radial for as long as possible, but even they had succumbed by then. They introduced their first wet radial tyre, the distinctive directional `gatorback', at Monaco in 1983, and their first radial slick for the 1984 season. From that point on, the radial ruled.

Michelin's long postponed arrival on the grand prix scene had a lot to do with the fact that, for all France's important contributions to the early years of motorsport, Formula One had been a high-octane game played out principally by the Germans, the Italians and the British. Matra had shown that France could compete, though, and when Renault — then still a Regie d'Etat, a state-owned company — decided to enter Fl in 1977, Michelin came with them. This was to be an all-French technology showcase, proof to the racing world that France could trade blows with the best.

There were obvious marketing reasons for Michelin to field a radial. Doing something different to the competition is a justification in its own right, but more importantly the Michelin name was historically wedded to radial tyre construction. Although it was two Englishmen — Gray and Sloper — who first patented the essential elements of the radial a year before the eruption of WWI, it was not until two years after WWII that the first radial tyre was developed for sale: the famous Michelin X. To be so intimately associated with the birth of the radial and then, 30 years on, arrive in F1 with a crossply would not have looked right. Just as significantly, there were good technical justifications for charting the radial course — inherent advantages that had already been verified on the road and in other motorsport arenas including Le Mans, and which help offset Goodyear's long years of Fl experience. These innate advantages were numerous and varied, many of them arising from the fact that the enhanced tread rigidity of a radial — provided by the circumferential tread plies, which act rather like a thin beam — substantially improves the consistency of contact with the road.

Braking and tractive grip increase as a result, slip angles are reduced on cornering, steering response is sharpened, lateral stability is improved and tread wear slashed. Rolling resistance is cut also, which helps save a little on fuel consumption, and the tyre 'grows' less under the centrifugal forces that accompany high-speed wheel rotation. Although Michelin couldn't have known it when they made the decision to enter F1, the improved control over ride height that this ensures would become a welcome benefit in the ground-effect era.

Failings of the radial were much fewer. Early radial road.tyres had suffered sudden breakaway at the limit of adhesion, making them treacherous inextrermis, but that problem had long since been ameliorated by changes in carcass construction. Increased sensitivity to wheel camber remained a disadvantage, but that could be straightforwardly addressed by changes to suspension geometry.

Being an exclusive bedmate of Renault did Michelin no favours in 1977. The turbocharged RS01, having first tested the previous winter, made its debut at Silverstone for the British Grand Prix in July, in the hands ofJean-Pierre Jabouille. It qualified a lowly 21st and lasted just 16 laps before expiring.

For a new team, such failure was forgiveable, but the poor performance continued through 1977 and '78. Spectacular engine detonations and a spate of fires reduced Renault to pitlane joke status; only later would the team's pioneering use of turbocharged power come to be recognised as visionary.

In fact, Renault, although eventually accumulating 15 race wins (the first, appropriately, the French Grand Prix with Jabouille in 1979, the last the 1983 Austrian Grand Prix with Alain Prost), contributed solidly rather than spectacularly to Michelin's success — a total of 296 points spread over eight seasons. Ironically, it was as a supplier to Italian and British teams that the French tyre maker scaled Fl 's heights.

Ferrari switched to Michelin for 1978, Carlos Reutemann chalking up the radial tyre's first Formula One victory at the season's second race in Brazil. The following year, Ferrari took Michelin to their first championship — a remarkable achievement for a tyre manufacturer which, at the start of the season, had amassed less than two years of Fl experience. Jody Scheckter narrowly won the drivers' crown from his team-mate Gilles Villeneuve, and so the 312T4 cleaned up the constructors' honours, too.

Goodyear regained the ascendancy in 1980, temporarily withdrew from Fl for a good part of 1981 due to the FISA/FOCA crisis, and then won again in 1982, so that Michelin's early success began to look like a flash in the pan. But two successive championship seasons in 1983 and 1984, first with Brabham (Nelson Piquet) and then McLaren (Niki Lauda), who also secured the constructors' championship, saw Michelin depart the fray in dominant form, bequeathing further development of the Fl radial to Pirelli and recent converts Goodyear. Any hope that Renault might finally deliver it a championship, fulfilling that glorious French dream, had receded with Prost's narrow defeat in 1983, after which the team went into terminal decline.

Almost two decades on, Michelin is to make a comeback in 2001, hoping this time to provide Bridgestone, now the world's biggest tyre maker, the kind of bruising that will boost sales on the global forecourt. It seems unlikely they can repeat the trick and introduce a second mould-breaking technology, but who knows? Is it too fanciful, for instance, to imagine that Michelin might seek some way to promote their PAX run-flat wheel/tyre system, which claims handling benefits alongside its get you-home capability? Let's hope it isn't.