These are the known mechanical and performance specifications for your 2011 Dafier STM 50.
Basic Specs

Engine
Displacement49.90 ccm (3.04 cubic inches)
Type
DetailsSingle cylinder, two-stroke
Max RPM
Compression7.0:1
Bore/Stroke40.3 x 39.0 mm (1.6 x 1.5 inches)
Valves/Cylinder
FuelingCarburettor
IgnitionCDI
Exhaust
Lubrication
CoolingLiquid
Performance
Horespower6.30 HP (4.6 kW)
Torque
Top Speed45.0 km/h (28.0 mph)
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity8.30 litres (2.19 gallons)
Emissions
Chassis
Frame TypeSteel
Rake
Trail
Front Suspension
Front Travel
Rear Suspension
Rear Travel
Seat
Seat Height
Alt. Seat Height
Total Height1,170 mm (46.1 inches)
Total Length2,200 mm (86.6 inches)
Total Width810 mm (31.9 inches)
Ground Clearance270 mm (10.6 inches)
Wheelbase
Dry Weight105.0 kg (231.5 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre100/80-17
Rear Tire/Tyre130/70-17
Front BrakesSingle disc
Front Brake Diameter
Rear BrakesSingle disc
Rear Brake Diameter
WheelsBlack rims
Comments
Chinese brand