The 2003-04 RS 125 carries on with the rounded 1999-style bodywork, five-spoke wheels and the Rotax 122 two-stroke on a PHBH 28 carburettor, with…
| MODEL | APRILIA RS 125 2003 - 2004 |
| Year | 2003 - 2004 |
| Engine Type | Rotax 122, single cylinder, two-stroke, reed valve |
| Displacement / Capacity | 124.8 cc / 7.6 cu in |
| Bore X Stroke | 54 x 54.5 mm / 2.13 x 2.15 in |
| Compression Ratio | 12.5:1 |
| Cooling System | Liquid cooled |
| Max Power | 2003: 21.5 kW / 29.2 PS @ 11000 rpm; 2004: 21 kW / 28.6 PS @ 10500 rpm |
| Max Torque | 2003: 18.7 Nm / 13.8 lb-ft @ 10000 rpm; 2004: 19 Nm / 14.0 lb-ft @ 10250 rpm |
| Ignition | — |
| Induction | Dell'Orto PHBH 28 BD carburettor |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 6 Speed |
| Clutch | Wet multi-plate |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Cast aluminium twin-spar (bridge) frame |
| Front Suspension | 40 mm hydraulic upside-down fork, non-adjustable, 120 mm / 4.7 in travel |
| Rear Suspension | Swingarm with hydraulic monoshock, adjustable preload, 120 mm / 4.7 in travel |
| Front Brakes | Single 320 mm floating disc, 4-piston axial caliper |
| Rear Brakes | Single 220 mm disc, 2-piston caliper |
| DIMENSION SPECS | |
| Overall Length | 1950 mm / 76.8 in |
| Overall Width | 720 mm / 28.3 in |
| Overall Height | 1135 mm / 44.7 in |
| Seat Height | 805 mm / 31.7 in |
| Wheelbase | 1345 mm / 53.0 in |
| Ground Clearance | 163 mm / 6.4 in |
| Dry Weight | 129 kg / 284.4 lbs (also quoted as 114 kg) |
| Wet Weight | 139 kg / 306.4 lbs |
| WHEEL SPECS | |
| Front Tyre | 110/70 ZR17 |
| Rear Tyre | 150/60 ZR17 |
| FUEL SYSTEM | |
| Fuel Capacity | 14 Litres / 3.7 US gal (incl. 3.5 L reserve) |
| Fuel Consumption | — |
| Top Speed | 155 km/h / 96.3 mph |
The 2003-04 RS 125 carries on with the rounded 1999-style bodywork, five-spoke wheels and the Rotax 122 two-stroke on a PHBH 28 carburettor, with slightly lower quoted output than the 1999-2002 bikes. Chassis, brakes and dimensions stayed essentially the same. Alongside it Aprilia offered the RS 125 Tuono, a half-naked version without the lower fairing and with a handlebar, and a Manuel Poggiali replica livery followed his 2003 250cc title.
