As one of the great sporting motorcycles of the mid-to-late 1970s, the Moto Guzzi 850 Le Mans was a masterpiece.
With all the major Italian manufacturers producing class-leading sporting machines, the mid-1970s was a halcyon time for the Italian motorcycle industry. In 1975, determined not to be outdone by Ducati, Laverda, and MV Agusta, Moto Guzzi released its spectacular 850 Le Mans.
Although derived from the existing 750 S and 750 S3 the Le Mans was faster and more stylish. With its cast alloy wheels, seat partly covering the fuel tank and small fairing with orange “Day-Glo” front section the Le Mans emphasised style over function. In doing so it also established a new order.
For the 850 Le Mans Moto Guzzi’s brilliant engineer Lino Tonti lengthened the stroke of the V7 Sport 750cc engine to 78mm and with 83mm pistons the displacement was 844cc. Most of the Le Mans’ performance boost over the 750 S3 came from the cylinder head. This included larger valves and higher (10.2:1) compression pistons, and combined with a pair of Dell’Orto 36mm carburettors breathing through open velocity stacks.
The high domed pistons increased performance, but cylinder flame propagation was inferior and the 850 Le Mans engine was prone to detonation and running hot. To improve throttle response the Le Mans also had a thinner and lighter flywheel.
Another update was to the exhaust system. Painted matt black to complement the rest of the styling, this featured single-walled 40mm header pipes, with a balance pipe across the front of the engine. Although quiet and efficient, unfortunately the black paint wasn’t very durable and rusted prematurely.
The claimed power for the Le Mans was 80 horsepower at 7300 rpm, but this was an optimistic claim.
As with the engine, the 850 Le Mans chassis was also similar to the 750 S3. The 35mm cartridge front fork included thinner walled tubes and the light alloy Borrani wheel rims were replaced by cast alloy FPS wheels, still with the same WM3 rim sizes (2.15×18 inch).
The Le Mans also featured the integrated braking system of the 750 S3 with Brembo 08 calipers, two drilled 300mm front discs and a 242mm rear disc. These brakes were extremely effective, and certainly amongst the best available in 1975. Although the 198kg dry weight was considerable for a sporting motorcycle, and the 1,70mm wheelbase moderate, the Le Mans was densely packaged and extremely compact.
But the raison d’être for the Le Mans was really about style more than performance. During the mid-1970s many European manufacturers saw the factory café racer as a way of countering the threat of cheaper, faster and continually improving Japanese motorcycles.
BMW started the trend with their ground-breaking R90S at the end of 1973, Norton followed with the John Player 850 of 1974, and in 1976 Ducati decided to put their limited edition 900 Super Sport into regular production. But none of these were as successful stylistic creations as the Le Mans.
The Moto Guzzi 850 Le Mans may have suffered from marginal execution and indifferent quality, but more than any other motorcycle it epitomizes the mid to late 1970s café racer style. And unlike some other deliberately styled motorcycles the Le Mans has stood the test of time.
The Le Mans was the right bike at the right time, offering similar performance to the Ducati 900 SS and Laverda 1000 3C, in a more civilised package. Tonti’s magnificent frame was still more than up to the task of harnessing the power of the 90-degree V-twin and the Le Mans was still one of the best handling motorcycles available.
With the excellent integral Brembo braking system it was hard to find a better-balanced all-round sporting motorcycle and the inclusion of an electric start and shaft final drive made it easy to live with. The Le Mans was a class-leading machine, and it had the looks to match.
Australia’s go-to-guy for classic motorcycle wisdom. Ian has written nearly 45 books on motorcycles that each offer unparalleled insight on the historical and technical development of particular makes and models.