At the heart of the 2015 AJS TN 12 naked motorcycle, AJS utilizes a 124 cc (7.6 cu in) air-cooled single cylinder, four-stroke layout. In factory specification, peak output is rated at 10.2 HP (7.4 kW) at 9,500 rpm, transferring power to the rear wheel through a 5-speed gearbox and chain final drive. With a specific output of 82.3 HP per liter, the engine character is indicating a tractable, stress-free state of tune focused on everyday usability and broad torque delivery.
On the scales, the TN 12 measures 153 kg (337 lbs) dry, translating to a power-to-weight ratio of 0.07 HP/kg (15 kg per horsepower). Rider ergonomics and chassis geometry center around a 820 mm (32.3 in) seat height — resulting in a taller command-style riding posture suited to medium-to-tall inseams, combined with a 1,340 mm (52.8 in) wheelbase engineered for quick, flickable steering geometry. The 18-liter (4.8 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's AJS archive, this model family spans 2 indexed model years from 2015 to 2016, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
82.3 HP/L
Power-to-Weight
0.07 HP/kg (15 kg/HP)
Standover Height
820 mm (32.3 in)
Engine
Displacement124.0 ccm (7.57 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsBalance shaft
Power10.2 HP (7.4 kW)) @ 9500 RPM
Bore x Stroke56.0 x 49.0 mm (2.2 x 1.9 inches)
Fuel SystemCarburettor
Fuel ControlOverhead Valves (OHV)
IgnitionCoil, CDI
CoolingAir
Transmission
Gearbox5-speed
Final DriveChain (final drive)
ClutchWet. multi-plate
Performance
Emission DetailsEuro 3
Chassis
Front SuspensionTelescopic fork
Rear SuspensionTwin reservoir shocks
Wheelbase1340 mm (52.8 inches)
Wheels & Brakes
Front Tyre110/70-17
Rear Tyre150/60-17
Front BrakesDouble disc
Front Brake Ø295 mm (11.6 inches)
Rear BrakesSingle disc
Rear Brake Ø230 mm (9.1 inches)
Dimensions & Weight
Dry Weight153.0 kg (337.3 pounds)
Power/Weight0.0666 HP/kg
Seat Height820 mm (32.3 inches) If adjustable, lowest setting.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
