AJS Model 31 650 Swift
Key specifications
Overview
### AJS Model 31 650 Swift: Classic Allrounder of 1959 The 1959 AJS Model 31 650 Swift is a quintessential motorcycle that embodies the spirit of the late 1950s British motorcycle culture. Positioned as an allrounder, this model was aimed at riders seeking versatility, reliability, and that distinct vintage charm. AJS, known for its engineering prowess and rich racing heritage, crafted the Model 31 to appeal to both daily commuters and weekend adventurers. Its classic lines and robust construction make it a sought-after piece for collectors and enthusiasts alike, standing out in a market teeming with competition. At the heart of the Model 31 lies a powerful 646cc twin-cylinder, four-stroke engine, capable of delivering 31.40 horsepower at 6000 RPM. The engine's design harmonizes a balance of performance with reliability, showcasing a compression ratio of 7.5:1 that allows for smooth acceleration and a satisfying riding experience. The 4-speed gearbox, paired with a wet multiplate clutch, ensures seamless shifts, while the chain final drive delivers power efficiently. Riders can expect a thrilling yet manageable ride, thanks to its air-cooled engine that keeps temperatures in check during long journeys while maintaining the nostalgic essence of classic motorcycling. The Model 31 doesn’t shy away from notable features and technology for its time. Its double cradle frame offers stability and strength, complemented by hydraulic telescopic front suspension and twin shock Girling rear suspension that absorb road imperfections with grace. The drum brakes, while less common in modern motorcycles, provide sufficient stopping power for the weight of 176 kg (388 pounds), instilling confidence in the rider. With a fuel capacity of 16 liters (4.23 gallons), the Model 31 is equipped to handle longer rides, making it a perfect companion for weekend getaways or leisurely countryside cruises. Not to forget, its kick starter adds to the authenticity of the ride, keeping the classic motorcycle experience alive. ####
Pros
Cons
- Timeless Design: The classic aesthetics and British styling make it a head-turner, appealing to vintage enthusiasts and collectors.
- Robust Performance: The balanced engine performance and reliable gearbox ensure a satisfying riding experience, whether commuting or touring.
- Comfortable Suspension: The well-engineered suspension system provides a smooth ride, effectively handling various road conditions.
- Limited Braking Power: The drum brakes, while adequate for the era, may feel underwhelming compared to modern disc brake systems, especially in emergency situations.
- Kick Start Only: The absence of an electric start can be a challenge for some riders, particularly in adverse conditions or for those unfamiliar with kick starting techniques.
- Weight Considerations: At 176 kg, some riders may find the Model 31 a bit heavy, especially when maneuvering in tight spaces or during low-speed handling.
Technical details
Source specification data
- Make
- AJS
- Model
- Model 31 650 Swift
- Category
- Allround
- Starter
- Kick
- Power
- 31.40 HP (22.9 kW)) @ 6000 RPM
- Clutch
- Wet multiplate
- Gearbox
- 4-speed
- Ignition
- Bobine
- Fuel System
- Carburettor
- Bore X Stroke
- 72.0 x 79.3 mm (2.8 x 3.1 inches)
- Compression
- 7.5:1
- Displacement
- 646.00 ccm (39.42 cubic inches)
- Cooling System
- Air
- Engine Details
- Twin, four-stroke
- Transmission Type Final Drive
- Chain
- Dry Weight
- 176.0 kg (388.0 pounds)
- Fuel Capacity
- 16.00 litres (4.23 gallons)
- Power Weight Ratio
- 0.1784 HP/kg
- Seat
- Dual
- Wheels
- Spoked
- Rear Tyre
- 3.25-19
- Frame Type
- Doble cradle
- Front Tyre
- 3.25-19
- Rear Brakes
- Expanding brake (drum brake)
- Front Brakes
- Expanding brake (drum brake)
- Rear Suspension
- Twin shock Girling
- Front Suspension
- Hydraulic telescopic