Photo ou archives : F-M. Dumas
615
BCR
500 HS – 1929
Comfort before anything else
At the end of the Twenties, the French motorcycle industry was in good shape. It exported a fifth of its production and only eight percent of new sales were imported machines. Alongside the major makes, like Peugeot and Terrot, a host of small manufacturers jostled for a place in the sun, and it was frequently these little companies that, in seeking to attract the enthusiasts, reached for more and made the technical breakthroughs.
Innovative Little Company
Typical of these innovative little companies was BCR, based in the Paris suburb of Kremlin-Bicetre, who produced a wide range of bikes between 1923 and 1930 — 175cc two-strokes, and 250cc, 350cc, and 500cc JAP-engined four-strokes.
Twin-Port Head
But the flagship BCR model was the 500 HS, powered by a 500cc Chaise engine with overhead valves and a twin-port head, one of the very first French machines to be fitted with rear suspension that actually performed as intended. In this case, the swinging fork acted directly on quarter-elliptic springs bolted to the frame, with sliding friction dampers rather than the telescopic shock absorbers used on modern machines. The rest of the design was conventional enough — the twin exhaust downpipes of the Chaise single were the height of fashion. Popular between 1920 and 1939, Chaise engines were made in Paris by Omnium Metallurgical Industries.
SPECIFICATIONS
Engine: 500cc (85x89nun) single-cylinder four-stroke
Valves: overhead valves, twin exhaust ports
Fuel System: carburettor
Transmission: 3-speed, chain drive
Suspension: (front) Druid parallelogram forks; (rear) swinging fork
Brakes: drum
Wheels, wire
Weight: 375 lb
Maximum Speed: 68 mph
The BCR 500 HS had a rather heavy look but was distinguished by its effective rear suspension system.