For 2021 the four-stroke SX 125 was reworked for Euro 5 with a new cylinder head and combustion chamber, revised ports, cam profile and valve gear, a…
| MODEL | APRILIA SX 125 2021 |
| Year | 2021 |
| Engine Type | Single cylinder, four-stroke, DOHC, 4 valves (Euro 5) |
| Displacement / Capacity | 124.2 cc / 7.6 cu in |
| Bore X Stroke | 58 x 47 mm |
| Compression Ratio | 12.6:1 |
| Cooling System | Liquid cooled |
| Max Power | 11 kW / 15 hp @ 10000 rpm |
| Max Torque | 11.2 Nm / 8.3 lb-ft @ 8000 rpm |
| Ignition | Electronic CDI |
| Induction | Fuel injection, Magneti Marelli MIU G4 ECU, 32 mm throttle body |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 6-speed |
| Clutch | Wet, multi-plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Twin-tube steel frame |
| Front Suspension | 41 mm upside-down fork, 240 mm / 9.4 in travel |
| Rear Suspension | Steel swingarm, monoshock with progressive linkage, 210 mm / 8.3 in travel |
| Front Brakes | Single 300 mm disc, floating caliper, Bosch ABS |
| Rear Brakes | Single 220 mm disc, floating caliper |
| DIMENSION SPECS | |
| Overall Length | 2075 mm / 81.7 in |
| Overall Width | 820 mm / 32.3 in |
| Overall Height | 1140 mm / 44.9 in |
| Seat Height | 880 mm / 34.6 in |
| Wheelbase | 1425 mm / 56.1 in |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 134 kg / 295 lbs |
| WHEEL SPECS | |
| Front Tyre | 100/80-17 |
| Rear Tyre | 130/70-17 |
| FUEL SYSTEM | |
| Fuel Capacity | 7 Litres / 1.85 US gal |
| Fuel Consumption | — |
| Top Speed | — |
For 2021 the four-stroke SX 125 was reworked for Euro 5 with a new cylinder head and combustion chamber, revised ports, cam profile and valve gear, a relocated throttle body, new airbox, catalyst and stainless silencer, plus fresh engine management. Peak power now arrives 700 rpm sooner and fuel use is claimed to be lower. Slimmer bodywork with a tank that flows into the seat, new graphics and a black frame and engine freshened the look, while ABS, the 41 mm fork and 17-inch wheels carry on.
