The 1988-1990 RX 125 was a major step forward: a Rotax-based 125 cc two-stroke with a Gilardoni cylinder, a Marzocchi upside-down fork, Aprilia's…
| MODEL | APRILIA RX 125 1988 - 1990 |
| Year | 1988 - 1990 |
| Engine Type | Single cylinder, two-stroke, Rotax 123 with Gilardoni cylinder and head |
| Displacement / Capacity | 124.8 cc / 7.6 cu in |
| Bore X Stroke | 54 x 54.5 mm |
| Compression Ratio | 11.5:1 |
| Cooling System | Liquid cooled |
| Max Power | 24.2 kW / 32.4 hp @ 10800 rpm |
| Max Torque | 20.6 Nm / 2.1 kgf-m / 15.2 lb-ft @ 10500 rpm |
| Ignition | — |
| Induction | Dell'Orto VHSB 34 LD carburettor |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 6 Speed |
| Clutch | — |
| Final Drive | #520 chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Marzocchi upside-down fork |
| Rear Suspension | Swingarm with Aprilia Progressive System linkage and fully adjustable Boge Sachs shock absorber |
| Front Brakes | Single 250 mm disc |
| Rear Brakes | Single 220 mm disc |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 115 kg / 253.5 lbs |
| WHEEL SPECS | |
| Front Tyre | 90/90-21 |
| Rear Tyre | 120/90-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 9 Litres / 2.4 US gal |
| Fuel Consumption | 5.5 L/100 km / 18.2 km/l / 42.8 US mpg |
| Top Speed | 132.2 km/h / 82.1 mph |
The 1988-1990 RX 125 was a major step forward: a Rotax-based 125 cc two-stroke with a Gilardoni cylinder, a Marzocchi upside-down fork, Aprilia's progressive-linkage rear shock and disc brakes at both ends replaced the simpler early layout. Badged as a Six Days model, it moved to modern 90/90-21 and 120/90-18 tyres and was tested by Motosprint at just over 130 km/h.
