Built around Xmotos's minibike, cross motorcycle platform, the 2008 Xmotos XB-21 utilizes a 50 cc (3.1 cu in) air-cooled single cylinder, four-stroke layout. In factory specification, peak output is rated at 3.5 HP (2.5 kW) at 8,500 rpm, transferring power to the rear wheel through a automatic gearbox and chain final drive. With a specific output of 70 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 XB-21 measures 50 kg (110 lbs) dry. Rider ergonomics and chassis geometry center around a 650 mm (25.6 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 950 mm (37.4 in) wheelbase engineered for quick, flickable steering geometry. The 3-liter (0.8 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Specific Output
70 HP/L
Standover Height
650 mm (25.6 in)
Engine
Displacement50.0 ccm (3.05 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power3.5 HP (2.5 kW)) @ 8500 RPM
Compression9.4:1
Bore x Stroke39.0 x 41.4 mm (1.5 x 1.6 inches)
CoolingAir
Transmission
GearboxAutomatic
Final DriveChain (final drive)
Chassis
Front SuspensionInverted hydraulic Adjustable shock
Rear SuspensionAdjustable Air /Oil shock Absorber
Wheelbase950 mm (37.4 inches)
Ground Clearance150 mm (5.9 inches)
Wheels & Brakes
Front BrakesExpanding brake (drum brake)
Rear BrakesExpanding brake (drum brake)
Dimensions & Weight
Dry Weight50.0 kg (110.2 pounds)
Power/Weight0.0696 HP/kg
Seat Height650 mm (25.6 inches) If adjustable, lowest setting.
Overall Length1320 mm (52.0 inches)
Fuel Capacity3.00 litres (0.79 US gallons)
Other
Color OptionsBlack, Red, Green, Blue, Yellow, carbon block, orange
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.
