MotoLibrary MotoLibrary
← Aprilia
Sport · 2004

RS 125 Replica

User Rating: /5 · No user ratings yet ✓ Your rating was saved
MotoLibrary Score
42 /100 Commuter
Power
28 HP
Top Speed
155 km/h
Torque
19 Nm
Engine
125 ccm

2004 Aprilia RS 125 Replica Technical Analysis & Specification Breakdown

Engineered by Aprilia for the sport motorcycle segment, the 2004 Aprilia RS 125 Replica pairs a 124.8 cc (7.6 cu in) liquid-cooled single cylinder, two-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 28.2 HP (20.6 kW) at 10,500 rpm while maximum torque reaches 19 Nm (14 lb-ft) at 10,250 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 226 HP per liter and a 250 rpm working window between peak torque (10,250 rpm) and peak power (10,500 rpm), the engine character is placing it firmly in high-revving supersport territory where top-end breathing dominates.

On the scales, the RS 125 Replica measures 139 kg (306 lbs) wet (curb), translating to a power-to-weight ratio of 0.2 HP/kg (4.93 kg per horsepower). Rider ergonomics and chassis geometry center around a 805 mm (31.7 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,345 mm (53 in) wheelbase engineered for quick, flickable steering geometry. The 14-liter (3.7 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 155 km/h (96 mph).

Specific Output
226 HP/L
Power-to-Weight
0.2 HP/kg (4.93 kg/HP)
Power Band Window
10,250–10,500 rpm
Standover Height
805 mm (31.7 in)
Engine
Displacement 124.8 ccm (7.62 cubic inches)
Engine Type Single cylinder, two-stroke
Engine Details Rotax 122: Aluminium cylinder with Nikasil coated liner. Reed valve intake.
Power 28.2 HP (20.6 kW)) @ 10500 RPM
Torque 19.0 Nm (1.9 kgf-m or 14.0 ft.lbs) @ 10250 RPM
Compression 12.5:1
Bore x Stroke 54.0 x 54.5 mm (2.1 x 2.1 inches)
Fuel System Carburettor. Dell Orto PHBH 28 BD
Fuel Control Membrane & power valve
Ignition Nippondeso CDI 071000-0910 QCA91
Lubrication Separate mixing with variable displacement, volumetric pump.
Cooling Liquid
Transmission
Gearbox 6-speed
Final Drive Chain (final drive)
Clutch Multi plate wet
Driveline Primary drive: Gearbox: 63/19 (3.32). Final drive: Chain: 17/40 (2.35).
Performance
Top Speed 155.0 km/h (96.3 mph)
Emission Details Euro 2, catalytic converter, secondary air system
Exhaust B-1172 e11 e3
Chassis
Frame Type Sloping twin-spar frame in thin wall box section cast aluminium, with reinforcement cross-ribbing.
Front Suspension Upside-down hydraulic fork, 40mm
Front Travel 120 mm (4.7 inches)
Rear Suspension Swingarm with asymmetric members in thin wall box section cast aluminium. Hydraulic monoshock with adjustable spring preload.
Rear Travel 120 mm (4.7 inches)
Wheelbase 1345 mm (53.0 inches)
Ground Clearance 163 mm (6.4 inches)
Wheels & Brakes
Front Tyre 110/70-ZR17
Rear Tyre 150/60-ZR17
Front Brakes Single disc. Axial caliper, 4 pistons
Front Brake Ø 320 mm (12.6 inches)
Rear Brakes Single disc. 2 pistons
Rear Brake Ø 220 mm (8.7 inches)
Wheels Aluminium alloy. Front 3.00 x 17, rear 4,00 x 17.
Dimensions & Weight
Weight incl. 139.0 kg (306.4 pounds)
Seat Height 805 mm (31.7 inches) If adjustable, lowest setting.
Overall Height 1135 mm (44.7 inches)
Overall Length 1950 mm (76.8 inches)
Overall Width 720 mm (28.3 inches)
Fuel Capacity 14.00 litres (3.70 US gallons)
Reserve Fuel 3.50 litres (0.92 US gallons)
Oil Capacity 0.60 litres (0.63 US quarts)
Other
Starter Electric
Color Options Poggiali Black, Poggiali White
Notes

Type SFF00

More from Aprilia
Buying Checklist

Before You Compare This Bike

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.
Rider Profile

Who Is This Bike For?

🟢
Beginner
A2 license compatible, manageable power.
🏁
Best For
Sport & Track
📏
Seat Height
80.5 cm / 31.7 in
Estimate

Ownership Cost Calculator

⛽ Fuel
per year
🔧 Maintenance
per year
🛡️ Insurance
per year
TOTAL

* Estimates only. Actual costs vary by country, riding habits, insurance provider and maintenance schedule.

MotoLibrary
🏠 Home 🔍 All Bikes 📂 Categories ⚖️ Compare 🎛️ Advanced Filter 🎯 Bike Finder 🎬 Videos 📰 Blog 📖 Glossary ℹ️ About

🍪 We use cookies for analytics & ads. Cookie Policy