At the heart of the 2008 Jianshe Knight JS125-28 sport motorcycle, Jianshe pairs a 123 cc (7.5 cu in) air-cooled single cylinder, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 8.2 HP (6 kW) at 7,500 rpm while maximum torque reaches 8 Nm (5.9 lb-ft) at 5,500 rpm, transferring power to the rear wheel through a 5-speed gearbox. With a specific output of 66.7 HP per liter and a 2,000 rpm working window between peak torque (5,500 rpm) and peak power (7,500 rpm), the engine character is indicating a tractable, stress-free state of tune focused on everyday usability and broad torque delivery.
On the scales, the Knight JS125-28 measures 125 kg (276 lbs) dry, translating to a power-to-weight ratio of 0.07 HP/kg (15.24 kg per horsepower). Rider ergonomics and chassis geometry center around a 775 mm (30.5 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,300 mm (51.2 in) wheelbase engineered for quick, flickable steering geometry. The 14.5-liter (3.8 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Specific Output
66.7 HP/L
Power-to-Weight
0.07 HP/kg (15.24 kg/HP)
Power Band Window
5,500–7,500 rpm
Standover Height
775 mm (30.5 in)
Engine
Displacement123.0 ccm (7.51 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power8.2 HP (6.0 kW)) @ 7500 RPM
Torque8.0 Nm (0.8 kgf-m or 5.9 ft.lbs) @ 5500 RPM
Compression10.0:1
Bore x Stroke54.0 x 54.0 mm (2.1 x 2.1 inches)
Fuel SystemCarburettor
IgnitionCDI
CoolingAir
Transmission
Gearbox5-speed
ClutchWet type,muti plate, hand operation
Chassis
Frame TypeSteel
Wheelbase1300 mm (51.2 inches)
Ground Clearance160 mm (6.3 inches)
Wheels & Brakes
Front BrakesSingle disc
Rear BrakesExpanding brake (drum brake)
Dimensions & Weight
Dry Weight125.0 kg (275.6 pounds)
Power/Weight0.0654 HP/kg
Seat Height775 mm (30.5 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.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
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.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
