AJS 31
The AJS 31 is a motorcycle from the British manufacturer Associated Motor Cycles (AMC).
development
Model 31
The AJS 31 is the further development of a four-stroke parallel twin with 500 cm³ that has been built since 1949. To secure sales in the United States, a version drilled to 600 cc appeared in 1956. Because a 650 cc machine was desired, AMC decided to design an engine with a new crankshaft. The motorcycle appeared in model year 1959 under the name AJS 31. Matchless , which is also part of the group , released the model as the G 12.
Model 31 had a compression ratio of 7.5: 1 and an AC system including an ignition distributor.
Model 31 De Luxe
The motorcycle had magneto ignition and manual ignition adjustment as well as a quick-release axle in the rear wheel and was characterized by more ornaments.
Model 31 CS
The machine was intended for off-road sports and was delivered with studded tires. It also had a higher compression and was lighter.
CSR model
The model corresponded to the 31 CS, but was designed for the road, with correspondingly different tires. The motorcycle reached a top speed of 177 km / h. Strong vibrations, which extended over the entire speed range, were disadvantageous.
Due to the large stroke and heavy pistons, all models tended to break the crankshaft.
Technical specifications
Parameter | Data of the AJS 31 De Luxe |
---|---|
Displacement | 646 cc |
Bore × stroke | 72 x 79.3 mm |
power | 40 hp at 6000 rpm |
compression | 7.5: 1 (optionally 8.5: 1) |
Carburetor | an Amal type 389, opening 28.5 mm |
ignition | Magneto ignition |
lubrication | Dry sump lubrication |
landing gear | lugged single-tube frame with double girders, telescopic fork at the front, strut swing arm at the rear |
brake | Drum brake front and rear |
tires | from 3.25 S 19 TT, rear 3.50 S 19 TT |
Empty weight | 195 kg |
consumption | 5 l per 100 km |
Top speed | 155 km / h |
literature
- Oldtimer Markt December 2010 issue, pp. 190–195