At the heart of the 2019 Benelli BN 251 naked motorcycle, Benelli features a 249 cc (15.2 cu in) liquid-cooled single cylinder, four-stroke configuration. In factory specification, peak output is rated at 25.8 HP (18.8 kW) at 9,250 rpm while maximum torque reaches 21.1 Nm (15.6 lb-ft) at 8,000 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 103.6 HP per liter and a 1,250 rpm working window between peak torque (8,000 rpm) and peak power (9,250 rpm), the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.
On the scales, the BN 251 measures 163 kg (359 lbs) wet (curb), translating to a power-to-weight ratio of 0.16 HP/kg (6.32 kg per horsepower). Rider ergonomics and chassis geometry center around a 795 mm (31.3 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,400 mm (55.1 in) wheelbase engineered for quick, flickable steering geometry. The 17-liter (4.5 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Benelli archive, this model family spans 6 indexed model years from 2015 to 2020, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
103.6 HP/L
Power-to-Weight
0.16 HP/kg (6.32 kg/HP)
Power Band Window
8,000–9,250 rpm
Standover Height
795 mm (31.3 in)
Engine
Displacement249.0 ccm (15.19 cubic inches)
Engine TypeSingle cylinder, four-stroke
Power25.8 HP (18.8 kW)) @ 9250 RPM
Torque21.1 Nm (2.2 kgf-m or 15.6 ft.lbs) @ 8000 RPM
Compression11.2:1
Bore x Stroke72.0 x 61.2 mm (2.8 x 2.4 inches)
Valves/Cylinder4
Fuel SystemInjection
Fuel ControlDouble Overhead Cams/Twin Cam (DOHC)
LubricationWet sump
CoolingLiquid
Transmission
Gearbox6-speed
Final DriveChain (final drive)
ClutchWet
Performance
Emission DetailsEuro 4. Catalytic converter and oxygen sensors.
Chassis
Frame TypeTrestle in steel tubes
Front Suspension41mm Upside-down forks
Front Travel120 mm (4.7 inches)
Rear SuspensionRear swing arm with central shock absorber
Rear Travel51 mm (2.0 inches)
Wheelbase1400 mm (55.1 inches)
Ground Clearance170 mm (6.7 inches)
Wheels & Brakes
Front Tyre110/70-ZR17
Rear Tyre150/60-ZR17
Front BrakesSingle disc. ABS
Front Brake Ø280 mm (11.0 inches)
Rear BrakesSingle disc. ABS
Rear Brake Ø240 mm (9.4 inches)
WheelsAluminum alloy
Dimensions & Weight
Weight incl.163.0 kg (359.4 pounds)
Seat Height795 mm (31.3 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.
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.
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.
