RX 125

1985 Aprilia RX 125 Technical Analysis & Specification Breakdown

Engineered by Aprilia for the cross - motocross motorcycle segment, the 1985 Aprilia RX 125 relies on a 124 cc (7.6 cu in) liquid-cooled single cylinder, two-stroke powerplant. In factory specification, peak output is rated at 34 HP (24.8 kW) at 10,750 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 274.2 HP per liter, the engine character is placing it firmly in high-revving supersport territory where top-end breathing dominates.

On the scales, the RX 125 measures 91 kg (201 lbs) wet (curb), translating to a power-to-weight ratio of 0.37 HP/kg (2.68 kg per horsepower). The 8.5-liter (2.2 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 130 km/h (81 mph).

Within MotoLibrary's Aprilia archive, this model family spans 17 indexed model years from 1984 to 2025, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.