For 1999 the RS 125 got its third look: rounder, fuller fairings, a single air duct on the right, a bigger lip over the headlight and five-spoke…
| MODEL | APRILIA RS 125 1999 - 2002 |
| Year | 1999 - 2002 |
| 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 | 22 kW / 29.9 PS @ 11250 rpm |
| Max Torque | 20 Nm / 14.8 lb-ft @ 10000 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 | 114 kg / 251.3 lbs (2002 also quoted as 129 kg) |
| Wet Weight | 139 kg / 306.4 lbs |
| WHEEL SPECS | |
| Front Tyre | 110/70-17 |
| Rear Tyre | 150/60-17 |
| 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 |
For 1999 the RS 125 got its third look: rounder, fuller fairings, a single air duct on the right, a bigger lip over the headlight and five-spoke wheels. Underneath it kept the 54 x 54.5 mm Rotax 122 two-stroke, now on a Dell'Orto PHBH 28 carburettor, in the aluminium twin-spar frame with a 40 mm upside-down fork and 320 mm front disc. The tank grew to 14 litres and ground clearance went up, making it a slightly more practical but still race-bred learner sportsbike.
