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AJS Model 20 500
1950Allround

AJS Model 20 500

Key specifications

Engine
498 cc
Power
20 HP
Weight
178 kg
Fuel type
petrol
Fuel capacity
3.6 L
Transmission
4-speed
Front brakes
Expanding brake (drum brake)
Rear brakes
Expanding brake (drum brake)

Overview

Introducing the 1950 AJS Model 20 500, a classic embodiment of mid-20th-century British motorcycle engineering that perfectly marries style, performance, and utility. Positioned as an allround motorcycle, the Model 20 is tailored for the discerning rider who appreciates the marriage of tradition and innovation. With its robust design and impressive specs, this model appeals not only to vintage bike collectors but also to enthusiasts looking for a reliable ride that resonates with the golden era of motorcycling. At the heart of the AJS Model 20 lies a powerful 498cc twin-cylinder, four-stroke engine that delivers a respectable 20 horsepower at 6,800 RPM. This spirited engine provides an exhilarating top speed of 137 km/h (85.1 mph), making it a thrilling ride for both casual outings and longer journeys. Its 7.0:1 compression ratio and efficient carburettor fuel system ensure smooth acceleration and responsiveness, while the 4-speed gearbox coupled with a wet multiplate clutch offers seamless shifting and a satisfying connection to the road. Riders will appreciate the Model 20's balance and stability, thanks to its single cradle frame and well-designed suspension system, which includes telescopic front forks and twin shock rear suspension. The AJS Model 20 is not just about performance; it showcases a range of features that elevate the riding experience. The classic design is complemented by practical elements such as air cooling for the engine and a reliable magneto ignition system, ensuring you can depend on this machine to start each time you throw a leg over it. The drum brakes, both front and rear, provide dependable stopping power, while the generous 13.5-litre fuel tank allows for extended rides without frequent refueling stops. The motorcycle's dimensions—178 kg in weight and compact size—make it easy to maneuver in various riding conditions, enhancing its appeal as an allrounder. **

Pros

  • Classic Design: The aesthetic of the Model 20 is reminiscent of the golden age of motorcycling, making it a head-turner on the road.
  • Reliable Performance: With its twin-cylinder engine and solid build, this motorcycle offers a smooth and reliable riding experience.
  • Easy Handling: Weighing in at just 178 kg, the Model 20 is light and nimble, making it suitable for both new riders and seasoned enthusiasts alike.

Cons

  • Limited Speed: While 137 km/h is respectable, modern motorcycles can easily exceed this, which may deter riders seeking high-speed thrills.
  • Drum Brakes: The expanding drum brake system, while reliable, lacks the stopping power and responsiveness of modern disc brakes.
  • Kick Start Only: The traditional kick starter can be less convenient than modern electric start systems, especially for riders accustomed to the ease of pressing a button.

Technical details

Source specification data

Make
AJS
Model
Model 20 500
Category
Allround
Starter
Kick
Power
20.00 HP (14.6 kW)) @ 6800 RPM
Clutch
Wet multiplate
Gearbox
4-speed
Ignition
Magneto
Top Speed
137.0 km/h (85.1 mph)
Fuel System
Carburettor
Bore X Stroke
66.0 x 72.8 mm (2.6 x 2.9 inches)
Compression
7.0:1
Displacement
498.00 ccm (30.39 cubic inches)
Cooling System
Air
Engine Details
Twin, four-stroke
Transmission Type Final Drive
Chain
Dry Weight
178.0 kg (392.4 pounds)
Fuel Capacity
13.50 litres (3.57 gallons)
Overall Width
710 mm (28.0 inches)
Overall Height
1,050 mm (41.3 inches)
Overall Length
2,190 mm (86.2 inches)
Power Weight Ratio
0.1124 HP/kg
Seat
Dual
Wheels
Spoked
Rear Tyre
3.25-19
Frame Type
Single cradle
Front Tyre
3.25-19
Rear Brakes
Expanding brake (drum brake)
Front Brakes
Expanding brake (drum brake)
Rear Suspension
Twin shock
Front Suspension
Telescopic