At the heart of the 1999 Aprilia ETX 125 enduro - offroad motorcycle, Aprilia relies on a 124.8 cc (7.6 cu in) liquid-cooled single cylinder, two-stroke powerplant. In factory specification, peak output is rated at 12.1 HP (8.8 kW) at 6,750 rpm while maximum torque reaches 14 Nm (10.3 lb-ft) at 6,000 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 97 HP per liter and a 750 rpm working window between peak torque (6,000 rpm) and peak power (6,750 rpm), the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.
On the scales, the ETX 125 measures 129 kg (284 lbs) wet (curb), translating to a power-to-weight ratio of 0.09 HP/kg (10.66 kg per horsepower). Rider ergonomics and chassis geometry center around a 915 mm (36 in) seat height — reflecting a long-travel chassis stance that favors ground clearance and off-pavement control, combined with a 1,475 mm (58.1 in) wheelbase engineered for balanced agility and highway composure. The 11-liter (2.9 US gal) fuel tank paired with a rated consumption of 6.1 L/100 km provides an estimated theoretical range of roughly 180 km (112 miles) between fill-ups, while factory top speed is listed at 100 km/h (62 mph).
Within MotoLibrary's Aprilia archive, this model family spans 4 indexed model years from 1987 to 2001, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
