At the heart of the 2007 Rieju MRX 125 cross - motocross motorcycle, Rieju utilizes a 124 cc (7.6 cu in) air-cooled single cylinder, four-stroke layout. In factory specification, peak output is rated at 14.5 HP (10.6 kW), transferring power to the rear wheel through a 5-speed gearbox and chain final drive. With a specific output of 116.9 HP per liter, 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 MRX 125 measures 107 kg (236 lbs) dry, translating to a power-to-weight ratio of 0.14 HP/kg (7.38 kg per horsepower). Rider ergonomics and chassis geometry center around a 900 mm (35.4 in) seat height — reflecting a long-travel chassis stance that favors ground clearance and off-pavement control, combined with a 1,332 mm (52.4 in) wheelbase engineered for quick, flickable steering geometry. The 7.4-liter (2 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Rieju archive, this model family spans 4 indexed model years from 2003 to 2008, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
116.9 HP/L
Power-to-Weight
0.14 HP/kg (7.38 kg/HP)
Standover Height
900 mm (35.4 in)
Engine
Displacement124.0 ccm (7.57 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power14.5 HP (10.6 kW))
Bore x Stroke54.0 x 54.0 mm (2.1 x 2.1 inches)
Fuel SystemCarburettor. Mikuni VM20SS
CoolingAir
Transmission
Gearbox5-speed
Final DriveChain (final drive)
Chassis
Frame TypePerimetral of double beam in steel of high resistance
Front SuspensionFork Ø 35 mm
Rear SuspensionMonoShock Absorder Progressive System (PRS)
Wheelbase1332 mm (52.4 inches)
Wheels & Brakes
Front Tyre90/90-21
Rear Tyre120/80-18
Front BrakesSingle disc. Double piston caliper
Front Brake Ø260 mm (10.2 inches)
Rear BrakesSingle disc
Rear Brake Ø200 mm (7.9 inches)
Dimensions & Weight
Dry Weight107.0 kg (235.9 pounds)
Power/Weight0.1355 HP/kg
Seat Height900 mm (35.4 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.
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.
