Jean Albert Gregoire was born in 1899, however he was not related to the manufacturer of the other car to bear this name, although when he was at school, he would claim that his uncle was the builder of the Gregoire cars to counter assertions that the company belonged to his father.
The truth was Gregoire Snr. was a railway engineer who was convinced that his son should receive a thorough grounding in physics to fit him for any subsequent career he might choose, and accordingly gave the boy a choice between the Ecole des Mines and the Ecole Poly technique for his final education.
Young Jean chose the Poly technique where, apart from his academic achievements, he became a brilliant athlete. He served during World War 1, took his doctorate in law after the Armistice, and started work in a textile factory. This had little attraction for him, so he resigned to go prospecting in Madagascar.
Racing Amilcars and Bugattis
On his return to France, Gregoire joined some friends to run an automobile
business in Versailles. There he began racing an Amilcar and a Bugatti for fun; he also met Pierre Fenaille, a wealthy amateur engineer who was to have a great influence on Gregoire's subsequent career. Fenaille suggested that Gregoire should join him in the construction of a light sports/racing car with the then-revolutionary feature of front-wheel drive
. It was to be called the Tracta, from the French words traction avant - 'front-wheel drive
The prototype, nicknamed 'Gephi', after the phonetic sound of the initials of Gregoire and Fenaille, was built in the works of Langlois & Journod of Courbevoie, Seine, and first ran in the summer of 1926. The front wheels featured independent suspension, and powered by a 1100cc SCAP engine fitted with a Cozette supercharger it was good for a 140 km/h top speed.
The first competitive outing for the new car was the Coupe de I' Armistice, a reliability trial for light cars and motorcycles run over a short circuit in the suburbs of Paris. The Tracta went up in flames, due to a short-circuit, and Gregoire only managed to put out the blaze by sacrificing an expensive travelling rug which had to be used as a fire blanket. Once the flames were out, the car was driven directly to the Levy-St, Nom hill-climb in the Chevreuse Valley. It made the fastest time of the day!
Two Tractas were entered for the 1927 Le Mans 24 Hours' race
, to be driven by Gregoire and Fenaille, but a pre-race crash in the team's Panhard support car eliminated Fenaille, and nearly put Gregoire out of the running. With his head swathed in bandages beneath his crash helmet, Gregoire managed to qualify in the event, averaging 48 mph over the 24 hours. Backed by Fenaille senior, Gregoire built several hundred Tracta cars between 1927 and 1934. Power units included 1100 and 1600cc SCAP engines, and 2.7-litre Continental and 3-litre Hotchkiss engines. Gregoire is claimed to have once said ... 'I do not think the Societe des Automobiles Tracta ever managed, no matter what the price was, to sell a car for more than its actual cost!'
The Tracta front-wheel drive layout was widely copied under licence, although it seems that Gregoire did not always receive the appropriate payment, especially from German companies. Gregoire designed an 11cv 6 cylinder car for Donnet in 1932. Only four prototypes were produced, one being shown at the Paris Salon of 1932 before Donnet went into liquidation.
He then worked with Lucian Chenard to design two cars for Chenard et Walcker. They were of advanced design but were not a commercial success. In 1937 he designed the Amilcar Compound, produced by Hotchkiss from 1938 to the Second World War, by which time 681 examples had been made. It was constructed using another of Grégoire's ideas, a cast Alpax (light alloy) chassis frame.
Other advanced features were rack and pinion steering and all independent suspension. But the car had its bad points, cable brakes
and gear-change linkage and a side valve engine although the latter was still common at this time. An overhead valve version came later. In 1936, he devised a diecast monocoque construction system which was tested on an Adler and which went into production on the Hotchkiss-built Amilcar Compound models launched at the 1937 Paris Motor Show. However, they were short-lived, as Amilcar ceased production during 1939.
Jean Gregoire pictured in his 2 seater sports car derived from the earlier Hotchkiss-Gregoire. It was fitted with a flat four cylinder 2200cc engine developing 130 bhp. The coachwork was by Henri Chapron.
The Australian Harnett-Gregoire
Refusing to work for the occupying German forces during World War 2, Gregoire was 'demobilised' by Hotchkiss. Working in secret, he designed the Aluminium-Francais Gregoire, a tiny four-seater 600cc flat-twin car whose Alpax integral chassis/body framing was obviously based on the Amilcar Compound. In fact, this model was never built under Gregoire's name, although there were ambitious, but short-lived, schemes to build it under licence in England as the Kendall, backed by the MP Denis Kendall, and in Australia as the Harnett-Gregoire. However, Panhard used the design as the basis of their Dyna range, which was a far more successful venture.
There was also a 2-Iitre Hotchkiss-Gregoire flat-four, available in small numbers from 1952
. The American Kaiser-Frazer of 1946 was originally to have followed this design under Gregoire licence. In 1952
, the SOCEMA-Gregoire gas-turbine car appeared at the Paris Salon; heresy of heresies, it had rear-wheel drive! Its 100 bhp Cema-turbo power unit drove through a Cotal electric gearbox, but the venture was still-born. Gregoire returned to his traditional muttons in 1956
with a derivative of the Hotchkiss-Gregoire built under his own name in small numbers in his works at Asnieres, Seine; these cars carried handsome two-seater coachwork by Henri Chapron, but faded from the buyers' lists around 1962
Arguably the most successful of Gregoire's post-war designs was his variable-rate suspension system, which was adopted, among others, by the Renault company. In any case, cars played only a part in the well-rounded life of J. A. Gregoire, for it is recorded that he was an authority on wine and mushrooms, a connoisseur of fine art and a competent pianist. And an author, whose autobiography l' Aventure Automobile (Best Wheel Forward) is one of-the classics of motoring literature.