The 1925 24 Hours of Le Mans was the 3rd Grand Prix of Endurance, and took place on 20 and 21 June 1925. It was the last of the three races spanning 1923 to 1925 to determine the winner of the Rudge-Whitworth Triennial Cup, as well the second race of the inaugural Biennial Cup.
Regulations The Automobile Club de l'Ouest (ACO) was pleased with how the 1924 regulations had worked. They adjusted the hood-test so that all cars could do it at the same time. The start was the logical point and to stop drivers from jumping the gun they would be lined up on the opposite side of the track. When the flag fell, they would run across, put the hood up and then start the car and get away as quick as possible. This became the origin of the famous “Le Mans start” that was an institution of the race until 1969, when safety concerns led to its end.Spurring 2011, p.126
The ACO offered a FF500 prize for the quickest to put up their hood,Spurring 2011, p.144 and the French agent for Truffault-Hartford suspension parts offered a FF1000 prize to the car leading after the first lap. The hoods now had to stay up for at least the first twenty laps (about two hours), and they had to be examined by officials for robustness before being pulled down. In addition to the 20-lap rule between fluid replenishment, no liquids could now be added after 3pm, in the final hour of the race.
Another important change was that every car had to cross the finish line and take the chequered flag to be classified. Using the cars’ average race speeds, the officials would calculate each car's estimated position on the track at the 24-hour mark. The sliding scale of target distances were again adjusted, though not as severely as 1924. The distances included the following:
Engine size 1924Minimum laps 1925Minimum laps Required Average speed 3000cc 115 118 2000cc 102 108 1500cc 93 99 1100cc 85 91
This year there were a number of cash prizes awarded by the ACO and assorted sponsors for events ranging from leading at certain times to quietest and most comfortable cars. Finally, this race was the culmination of the inaugural Triennial and Biennial Cups. Only seven manufacturers' entries remained who had completed both the 1923 and 1924 races to be in contention for the Triennial Cup. There were eight entrants for the Biennial Cup. Both would be decided solely by the results in this race, not from the combined aggregate.Spurring 2011, p.125
The track With the further success of the race, the ACO looked at getting more permanent facilities. They tried to purchase the properties around the pit area at Les Raineries however the prices demanded by the landowners were too high.Laban 2001, p.46 Frustrated, the ACO instead resolved to relocate with more amenable neighbours by the hippodrome along Les Hunaudières, the main route from Le Mans to Tours.Clausager 1982, p.32-4 A new temporary pits, lighting and grandstands were set up on the Mulsanne Straight. The national roads board assisted by widening and sealing the track around the new pits area to assist with the new start procedure.
Entries The international attention that had come with Bentley's win the previous year drew a much bigger list of entries. Of the 68 submitted, 55 arrived for scrutineering. But this included 15 cars from outside France. Sunbeam, AC and Austin joined Bentley from Great Britain, and there were teams from Italy (Diatto and OM) and the USA (Chrysler). There were also six different tyre companies represented at the race.
Category Entries Classes Large-sized engines 19 / 17 over 2-litre Medium-sized engines 23 / 19 1.1 to 2-litre Small-sized engines 13 / 13 up to 1.1-litre Total entrants 55 / 49 Note: The first number is the number of arrivals, the second the number who started.
After their distance victory the previous year, Bentley returned with a full works car to support John Duff’s privateer entry and carrying the “favourites” tag.Clarke 1998, p.20-2: Motor Jun23 1925 Duff had the same car as last year. The works car had an uprated 3.3-litre engine and was driven by Bentley salesman Bertie Kensington-Moir and Dudley Benjafield, a Harley St doctor and Bentley racer at Brooklands.
Chenard-Walcker were well-placed in both Rudge-Whitworth Cups and arrived with four cars split over two engine-sizes to hedge their bets. The plan was to chase the Cups with the smaller cars and go for the distance victory with the bigger ones. Once again, their lead drivers René Léonard and André Lagache were assigned their primary car – the latest version of the 22CV. This was lower and now had a straight-8, 3.95-litre engine. The second car was driven by 1924 team hero André Pisart, and Jacques ‘Elgy’ Ledure, formerly with Bignan.Spurring 2011, p.132-3 The smaller cars were inspired by the streamlined Bugatti Type 32 ‘tank’. Designer Henri Toutée's advanced Z1 was a racing version of the upcoming Y8 tourer. It had a new 1.1-litre engine produced 50 bhp and had new steering and 4-wheel braking, making it very quick. They were assigned to Sénéchal/Loqueheux and Glaszmann/de Zúñiga.Spurring 2011, p.131
After coming very close to victory the previous year, La Lorraine-Dietrich arrived with three of their B3-6 cars. The cars had been lightened, and the troublesome steel “artillery” wheels were replaced by Rudge-Whitworth wire ones. All three cars were now on Englebert tyres.Spurring 2011, p.128-9 Last year's driver pairings were shuffled a bit: Gérard de Courcelles and André Rossignol stayed together, but Brisson was with Stalter and Robert Bloch with the new Léon Saint-Paul.
Sunbeam were now ready for Le Mans and arrived with two cars. Founded in 1899, the company came to pre-war prominence with French designer Louis Coatalen. Making aero-engines for Bristol during the war, they had been forced to merge with Talbot-Darracq in 1920, becoming STD. Already with a strong racing pedigree, with Land Speed Records for Kenelm Lee Guinness and Malcolm Campbell, they became the only British carmaker to win a Grand Prix in the first half of the twentieth century when Sir Henry Segrave won the 1923 French Grand Prix. Coatalen developed the two cars for Le Mans from the current production 24/60 model. The 2.9-litre engine put out 90 bhp with a 4-speed gearbox. With 4-wheel braking, they also ran with Rapson tyres like the Bentleys. Segrave was perhaps the most well-known British racing driver, and was paired with George Duller, while the second car had works drivers Jean Chassagne and Autocar journalistLaban 2001, p.44 Sammy Davis.Spurring 2011, p.133-5 Originally a British company, Talbot had been bought out by the British-owned, Paris-based Darracq company 1919, which then merged with Sunbeam the next year. Its production was relocated to Paris and it was two of the 1.5-litre Type C, first made in 1923, that were sent to Le Mans.Spurring 2011, p.154-5
Ariès brought a newmodel to Le Mans this year. The Type S GP2 was lowered, with a shorter wheelbase and an improved 3-litre engine. This year company-owner Baron Charles Petiet was able to procure the services of the great Louis Wagner who had raced Darracq, FIAT and Mercedes before the war, and recently with the Alfa Romeo works team. Ariès also bought a pair of its smaller CC2 1100cc cars to compete for the 1924-5 Biennial Cup.Spurring 2011, p.149
The biggest car in the field was a Sizaire-Berwick, in the Anglo-French company's only Le Mans appearance. Designed by Maurice Sizaire in Paris, the cars had originally been made in London. Financial struggles saw that factory bought by Herbert Austin who put his own engines in the cars. The model at Le Mans had been built in France, its 4.5-litre engine putting out 65 bhp. Although big, it was also heavy and its performance lagged behind the new racing tourers.Spurring 2011, p.163
This year cars came from Italy for the first time, with two Italian teams. Diatto was an old industrial firm and had built railway-stock in the 19th century, including carriages for the famous Orient Express. It branched into cars in 1905 and had a solid pre-war racing pedigree. The works team was now run by Alfieri and Ernesto Maserati and four cars came to Le Mans. The Tipo 35 had a 3-litre engine putting out 75 bhp and capable of 135 kp/h (85 mph), while the pair of Tipo 30s had 55 bhp 2-litre engine.Spurring 2011, p.150-2 Officine Meccaniche (OM) was a Milanese company that likewise building was founded, in 1899, building railway wagons. Car production started in 1918. The 665 “Superba” had come out five years later. It had a 2-litre engine, 4-speed gearbox and 4-wheel brakes. The model S was a short-wheelbase, racing version with Pirelli tyres and an improved engine that put out 60 bhp capable of over 120 kp/h (75 mph); and it had performed well at the national level. Three cars came to Le Mans with Italian drivers including Grand Prix drivers “Nando” Minoia and Giulio Foresti.Spurring 2011, p.138
It was also the first race for an American team. The first Chrysler-badged car had only been unveiled in 1924. The Chrysler Six Model B-70 had a 3.3-litre straight-6 engine that produced 70 bhp capable of over 110 kp/h (70 mph). Dwarfed by the production of Ford and General Motors in the US, Chrysler set out to outset its rivals in Europe. The French agent was Gustave Baehr's Grand Garage Saint-Didier in Paris, and it was they who entered two cars into the race. In the end there was only time to prepare one – for former Lorraine-Dietrich driver Henri Stoffel and Lucien Desvaux, ex-Salmson.Spurring 2011, p.140-1 The other new British team to enter was AC Cars. Originally making a 3-wheel delivery vehicle called an Auto Carrier, it was the post-war investment by famous British racer Selwyn Edge, that got the new AC Six into production. The entry was raced by John Joyce and Victor Bruce (engaged to famous female racer Mary Petre).Spurring 2011, p.166
Louis Reval had been in the automotive industry since the turn of the century. His company, Automobiles Reval, was only three years old. The latest iteration of his Type A had a 2.5-litre engine with a short-wheelbase Sports chassis and could reach 120 kp/h (75 mph).Spurring 2011, p.155-6 Automobiles Gendron (also known as GM) was originally an auto-parts manufacturer, but started making cars in 1922. Two of the long-wheelbase GC-2 1.5-litre tourers were entered. Company founder Marcel Gendron himself drove one car, with accomplished aircraft test-pilot Lucien Bossoutrot.Spurring 2011, p.158 Similarly, Henri Précloux was new to car-manufacturing, having opened E.H.P. in 1921, making small-engined cars and cyclecars that were competitive racers. The D4 model was new for 1925, and the DT was a higher-specification variant with a 1.5-litre CIME engine and 4-speed gearbox.Spurring 2011, p.158-9
Rolland-Pilain had released two new models this year: the B25 road-car and a “Super Sport” version of the B23, and it was three of the latter that were at Le Mans. It had a longer wheelbase, “boat-tail” rear end and a more powerful 2-litre engine.Spurring 2011, p.142 The cars of Delalande/Chalamel and de Marguenet/Sire were entered in the Triennial Cup and with two cars, the team had a good chance in the Triennial field of seven. Bignan were struggling financially and only sent a pair of their 2-litre cars, to contest both of the ongoing Cups. The distinctive cars now sported on a single large headlight in the top of the radiator grill. Regular team drivers Jean Martin and Jean Matthys had one car, while Henri Springuel drove with Pierre ClauseSpurring 2011, p.146