1963 Lotus 25 racing car designed by Colin Chapman for the 1962 Formula 1 season
From blown diffusers to front-tyre-warming, toe-angle-adjusting steering columns, both born then banned in the past two decades, Formula One has been defined by relentless rule-bending engineering innovations since its inception. However, the most primal of them all doesn’t even hail from this century; it supersedes carbon fibre as F1’s go-to construction material in the 1980s.
The Lotus 25 of 1962 was the first F1 car to eschew the sport’s then de rigeur tubular spaceframe in favour of a stressed monocoque (French for “single-hull”). Like many game-changers in history, the idea was first penned on the back of a napkin. In this instance, Colin Chapman was doodling during a lunch with fellow F1 designer Frank Costin.
The monocoque wasted less surface space, tripled the strength and at just 29 kg, effectively halved the weight of the spaceframe of its predecessor. The hull – effectively a pair of pontoons held together by two bulkheads fore and aft of the driver – was sculpted around the driver’s body and the latter positioned almost entirely horizontally and earned the nickname “The Bathtub”. This construction dramatically narrowed the car (the 25 was the slimmest F1 had ever seen), aiding aerodynamic efficiency and therefore top speed.
Tickling the scales at a mere 451 kg and powered by a 150 kW 1,5-litre Coventry Climax V8, the Lotus 25 powered to success in seven out of 10 races in 1963 and six out of 10 races in 1965. It garnered the mercurial Jim Clark his sole pair of F1 crowns; and Lotus’ debut constructor’s title.
Their benefit was ably demonstrated and, over time, the use of monocoques became the default construction method for single-seater racers. The sheet aluminium would evolve into a honeycomb and then later composites, but the fundamentals of a tub with engine, transmission and suspension bolted on to it has never changed.
With its legacy immortalised in F1’s history books, there’s no better way for the Lotus 25 to celebrate its 60th birthday.