Engineered by Triumph for the naked motorcycle segment, the 2021 Triumph Trident 660 features a 660 cc (40.3 cu in) liquid-cooled in-line three, four-stroke configuration. In factory specification, peak output is rated at 81 HP (59.1 kW) at 10,250 rpm while maximum torque reaches 63.7 Nm (47 lb-ft) at 6,250 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 122.7 HP per liter and a 4,000 rpm working window between peak torque (6,250 rpm) and peak power (10,250 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 Trident 660 measures 189 kg (417 lbs) dry, translating to a power-to-weight ratio of 0.43 HP/kg (2.33 kg per horsepower). Rider ergonomics and chassis geometry center around a 805 mm (31.7 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,401 mm (55.2 in) wheelbase engineered for quick, flickable steering geometry. The 14-liter (3.7 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Triumph archive, this model family spans 6 indexed model years from 2021 to 2026, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
122.7 HP/L
Power-to-Weight
0.43 HP/kg (2.33 kg/HP)
Power Band Window
6,250–10,250 rpm
Standover Height
805 mm (31.7 in)
Engine
Displacement660.0 ccm (40.27 cubic inches)
Engine TypeIn-line three, four-stroke
Power81.0 HP (59.1 kW)) @ 10250 RPM
Torque63.7 Nm (6.5 kgf-m or 47.0 ft.lbs) @ 6250 RPM
Compression12.0:1
Bore x Stroke74.0 x 51.1 mm (2.9 x 2.0 inches)
Valves/Cylinder4
Fuel SystemInjection. Multipoint sequential electronic fuel injection with electronic throttle control
Fuel ControlDouble Overhead Cams/Twin Cam (DOHC)
CoolingLiquid
Transmission
Gearbox6-speed
Final DriveChain (final drive)
ClutchWet. multi-plate. slip and assist
DrivelineX-ring chain
Performance
ExhaustStainless steel 3 into 1 header system with low single sided stainless steel silencer
Chassis
Frame TypeTubular steel perimeter
Rake24.6°
Trail107 mm (4.2 inches)
Front SuspensionShowa 41mm upside down separate function forks (SFF)
Front Travel120 mm (4.7 inches)
Rear SuspensionShowa monoshock RSU. with preload adjustment
Rear Travel134 mm (5.3 inches)
Wheelbase1401 mm (55.2 inches)
Wheels & Brakes
Front Tyre120/70-R17
Rear Tyre180/55-R17
Front BrakesDouble disc. ABS. Two-piston calipers.
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.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
