Photo ou archives : F-M. Dumas
7614
BMW
750 R17 – 1935
Technical advance
The first BMW 750cc motorcycles went on sale in 1928 — they were the side-valve R62 (78x78mm) and the oversquare (83x68mm) R63 with overhead-valves.
The First BMW with Pressed-Steel Frame ...
In 1929, the R62 was replaced by the R11, which was broadly similar but had a pressed-steel double-cradle frame that started a trend throughout the industry and was used by the majority of manufacturers, especially in Germany. Once again, a side-valve version was paralleled by an overhead-valve model, the R16, with the same bore and stroke as the R63.
... and Telescopic Forks
The major innovation on the two new 750s launched in 1935 — the R12 and R17 — was their hydraulically-damped telescopic forks. It was the first time this type of suspension had appeared on a mass-produced motorcycle. Still with an oversquare engine — more suitable to the high speeds of which an overhead-valve machine was capable — the R17 had practically the same power unit as the earlier R16 but was fitted — like the R12 — with a new four-speed gearbox controlled from the tank by an automobile-type shift lever pivoting directly in a turret on the gearbox lid. It remained in production until 1937. Very expensive — but prestigious — the R17 was the most powerful motorcycle built by BMW until its 600cc R68 of 1952 and the last overhead-valve 750 from the marque up to the R75/5 of 1969.
SPECIFICATIONS
Engine: 736cc (83x68mm) air-cooled flat-twin four-stroke
Power Rating: 33 hp @ 5000 rpm
Valves: overhead
Fuel System: two 24 mm carburettors
Transmission: 4-speed lever shift, shaft final drive
Suspension: hydraulic telescopic forks (front); rigid (rear)
Brakes: drum (front & rear)
Wheels: 3.50x19 inch (front & rear)
Weight: 403 lb
Maximum Speed: 87 mph (solo); 75 mph (with sidecar)
The peak of German technology in the mid-1930s — the BMW 750 R17 was an expensive motorcycle, while the side-valve R12 was less costly.