At the heart of the 2004 Derbi Atlantis Bullet scooter motorcycle, Derbi utilizes a 49.9 cc (3 cu in) air-cooled single cylinder, two-stroke layout. Internal engine geometry specifies a bore and stroke of 40.0 x 39.3 mm (1.6 x 1.5 inches) with a 10.5:1 compression ratio.
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 1,265 mm (49.8 in) wheelbase engineered for quick, flickable steering geometry. The 7-liter (1.8 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Derbi archive, this model family spans 2 indexed model years from 2004 to 2006, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Standover Height
795 mm (31.3 in)
Engine
Displacement49.9 ccm (3.04 cubic inches)
Engine TypeSingle cylinder, two-stroke
Engine DetailsSingle cylinder, two-stroke
Compression10.5:1
Bore x Stroke40.0 x 39.3 mm (1.6 x 1.5 inches)
Fuel SystemCarburettor
CoolingAir
Chassis
Front SuspensionHydraulic fork, 25 mm
Front Travel65 mm (2.6 inches)
Rear SuspensionMono shock
Rear Travel60 mm (2.4 inches)
Wheelbase1265 mm (49.8 inches)
Wheels & Brakes
Front Tyre120/70-12
Rear Tyre120/70-12
Front BrakesSingle disc
Front Brake Ø190 mm (7.5 inches)
Rear BrakesExpanding brake (drum brake)
Rear Brake Ø110 mm (4.3 inches)
Dimensions & Weight
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.
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.
