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MotoLibrary Score
42/100Commuter
Power/Weight
0.21 hp/kg
Torque
37 Nm
Engine
652 ccm
Technical Overview
2007 CR&S VUN Underpowered Technical Analysis & Specification Breakdown
Engineered by CR&S for the naked motorcycle segment, the 2007 CR&S VUN Underpowered features a 652 cc (39.8 cu in) liquid-cooled single cylinder, four-stroke configuration. In factory specification, peak output is rated at 29 HP (21.2 kW) at 6,000 rpm while maximum torque reaches 37 Nm (27.3 lb-ft) at 4,000 rpm, transferring power to the rear wheel through a 5-speed gearbox. With a specific output of 44.5 HP per liter and a 2,000 rpm working window between peak torque (4,000 rpm) and peak power (6,000 rpm), the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the VUN Underpowered measures 135 kg (298 lbs) dry, translating to a power-to-weight ratio of 0.21 HP/kg (4.66 kg per horsepower). Rider ergonomics and chassis geometry center around a 800 mm (31.5 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,368 mm (53.9 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.
Specific Output
44.5 HP/L
Power-to-Weight
0.21 HP/kg (4.66 kg/HP)
Power Band Window
4,000–6,000 rpm
Standover Height
800 mm (31.5 in)
Engine
Displacement652.0 ccm (39.79 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power29.0 HP (21.2 kW)) @ 6000 RPM
Torque37.0 Nm (3.8 kgf-m or 27.3 ft.lbs) @ 4000 RPM
Compression9.7:1
Bore x Stroke100.0 x 83.0 mm (3.9 x 3.3 inches)
Valves/Cylinder4
Fuel SystemInjection. Walbro integrated
LubricationDry sump
CoolingLiquid
Transmission
Gearbox5-speed
ClutchWet multiplate
Chassis
Frame TypeSteel tubes and machined light alloy plates compound
Front SuspensionHydraulic fork
Front Travel120 mm (4.7 inches)
Rear SuspensionSwingarm
Rear Travel128 mm (5.0 inches)
Wheelbase1368 mm (53.9 inches)
Ground Clearance150 mm (5.9 inches)
Wheels & Brakes
Front Tyre120/70-ZRX17
Rear Tyre160/60-ZRX17
Front BrakesSingle disc
Rear BrakesSingle disc
Dimensions & Weight
Dry Weight135.0 kg (297.6 pounds)
Power/Weight0.2148 HP/kg
Seat Height800 mm (31.5 inches) If adjustable, lowest setting.
Overall Length1980 mm (78.0 inches)
Fuel Capacity14.00 litres (3.70 US gallons)
Notes
CR and S is an abbreviation of Cafe Racers and Superbikes.
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.
