Photo ou archives : M. Woollett
8305
MARTINSYDE
677 V-twin & Articulated Sidecar - 1922
Banking on success
At the end of WWI, Martinsyde, Britain's third largest aircraft manufacturer, was forced – like so many other companies – to look for new products to make. The motorcycle sector looked promising, and chief engineer Howard Newman quickly drew up plans for a high-quality V-twin.
Unusual Layout
This long-stroke engine (70x88mm) of 677cc had an unusual F-head configuration, with overhead exhaust valves operated by pushrods and rockers, and side intake valves.
Racing at Brooklands
Martinsyde – an abbreviation of the names of its founders, Martin and Handasyde – was based at Woking, just down the road from the famed Brooklands circuit where its aircraft were erected. It had some notable successes on the famed concrete oval, such as its victory in the 750cc class of the 1921 500-mile race, when a Martinsyde covered the distance at an average of over 55 mph, a remarkable feat for the time. Sidecar racing was equally popular at Brooklands, and in June 1922, a Martinsyde with a banking sidecar appeared on the track. Paneled in aluminum with a streamlined celluloid windshield (a reminder of Martinsyde's long aviation experience), it had a tubular chassis linked to the frame of the bike by articulated joints, a method also successfully used by the Flexible Sidecar company of Ohio.
SPECIFICATIONS
Engine: 677cc (70x88 mm) air-cooled V-twin four-stroke
Power Rating: 26 hp @ 5000 rpm
Valves: F-head (overhead intake, side exhaust)
Fuel System: Amac carburetor
Transmission: separate 3-speed; chain final drive
Suspension: girder forks with double friction dampers (front); rigid (rear)
Brakes: dummy belt rim (rear)
Wheels: 21 inch (front); 20 inch (rear)
Weight: 346 lb (solo)
Maximum Speed: 98 mph (solo), 70 mph (combination)
Two "speed demons" try their 6 hp Martinsyde V-twin and its articulated sidecar on the Brooklands banking in June 1922.