These are the known mechanical and performance specifications for your 2007 Rieju SMX 125.
Basic Specs

Engine
Displacement124.00 ccm (7.57 cubic inches)
Type
DetailsSingle cylinder, four-stroke
Max RPM
Compression
Bore/Stroke54.0 x 54.0 mm (2.1 x 2.1 inches)
Valves/Cylinder
FuelingCarburettor. Mikuni VM20SS
Ignition
Exhaust
Lubrication
CoolingAir
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity7.40 litres (1.96 gallons)
Emissions
Chassis
Frame Type
Rake
Trail
Front SuspensionFork Ø 35 mm
Front Travel
Rear SuspensionMonoShock Absorder Progressive System
Rear Travel
Seat
Seat Height900 mm (35.4 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height1,135 mm (44.7 inches)
Total Length1,994 mm (78.5 inches)
Total Width800 mm (31.5 inches)
Ground Clearance
Wheelbase1,332 mm (52.4 inches)
Dry Weight108.0 kg (238.1 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre90/90-21
Rear Tire/Tyre120/80-18
Front BrakesSingle disc. Double piston
Front Brake Diameter260 mm (10.2 inches)
Rear BrakesSingle disc
Rear Brake Diameter200 mm (7.9 inches)
Wheels
Comments
Spanish made biike with a Yamaha 125 4T engine.