2021 Aprilia RS 660 vs 2025 Harley-Davidson Sportster S

Full specifications comparison • 2 motorcycles

Comparing 2 motorcycles
2021 Aprilia RS 660 2021 Aprilia RS 660

Sport

Engine
Four stroke, forward facing parallel twin, DOHC with silent chain drive on the right side, four valves per cylinder
Power
100 hp / 73.5 kW @ 10,500 rpm
Top Speed
N/A
Weight
183 kg / 403.4 lbs
2025 Harley-Davidson Sportster S 2025 Harley-Davidson Sportster S

Sport

Engine
Four stroke, 60° V-twin Revolution Max 1250, Chain-driven, DOHC, hydraulic self-adjusting lifters, intake & exhaust VVT, four valves per cylinder
Power
121 hp / 90 kW @ 7500 rpm
Top Speed
N/A
Weight
228 kg / 502 lbs
Full Specifications
General
Year20212025
Make ModelAprilia RS 660Harley Davidson Sportster S
Dimensions
Seat Height815 mm / 32.0 in765 mm / 30.1 in
Wheelbase1370 mm / 53.9 in1520 mm / 59.8 in
Ground Clearance-90 mm / 3.5 in
Height-1085 mm / 42.7 in
Length-2270 mm / 89.42 in
Seat Height (Laden)-734 mm / 28.9 in
Width-840 mm / 33.1 in
Weights & Capacities
Dry Weight (kg)169221
Wet Weight (kg)183 228
Dry Weight169 kg / 372.5 lbs221 kg / 487 lbs
Fuel Capacity15 Litres / 3.9 US gal11.7 Litres / 3.1 US gal
Wet Weight183 kg / 403.4 lbs228 kg / 502 lbs
Performance
Max Power100 hp / 73.5 kW @ 10,500 rpm121 hp / 90 kW @ 7500 rpm
Max Torque67.0 Nm / 6.83 kgm @ 8,500 rpm126 Nm / 93 lb-ft @ 6000 rpm
Engine
Displacement659 cc / 40.2 cu-in1252 cc / 76.4 cu-in
Engine DetailFour stroke, forward facing parallel twin, DOHC with silent chain drive on the right side, four valves per cylinderFour stroke, 60° V-twin Revolution Max 1250, Chain-driven, DOHC, hydraulic self-adjusting lifters, intake & exhaust VVT, four valves per cylinder
Bore x Stroke81 x 63.93 mm105 x 72.3 mm
Compression Ratio13.5: 112.0:1
Cooling SystemLiquid cooled with radiator and water-oil heat exchangerLiquid cooled
EmissionsEuro 5 CO2 emissions - 116 g /km-
ExhaustAkrapovič - for race use only2-into-1-into-2, catalyst in muffler
Fuel InductionAirbox with front air intake. 2 ∅48 mm throttle bodies, Ride-By-Wire managementElectronic Sequential Port Fuel Injection (ESPFI)
LubricationWet sumpSemi-dry sump
StarterElectricElectric
Drivetrain
ClutchWet, multi-plate, slipperMechanical, 8 plate wet, assist & slip, 1090N
Final DriveChain, with drive ratio: 17/43Belt, 34/80 ratio
Gear Ratios-1st 12.21 / 2nd 9.022 / 3rd 6.994 / 4th 5.641 / 5th 4.731 / 6th 4.131
Primary Drive-Gear, 49/89 ratio
Transmission / Drive6 Speed, AQS Aprilia Quick Shift6 Speed
Chassis
Frame TypeDouble beam aluminium frame with detachable rear seatStressed-member, high strength low alloy steel trellis frame; stamped, cast, and forged junctions; MIG welded; aluminum forged mid-structure
Suspension - FrontKayaba upside down fork ∅ 41 mm with counter spring, aluminium feet for fixing radial calipers. Adjustable for rebound, compression and spring preload.43 mm inverted fork with compression, rebound and spring preload adjustability. Aluminium fork triple clamps
Suspension - RearAluminium swingarm with asymmetrical trusses. Monoshock with adjustable counter spring: rebound and spring preload.Linkage-mounted, piggyback monoshock with compression, rebound and hydraulic spring preload adjustability
Fork Angle-28°
Lean Angle-35°
Rake24.1°30°
Swingarm-High strength low alloy steel, tubular sections, stamped x-member, forged axle junctions; MIG welded
Trail104.6 mm148 mm / 5.8 in
Wheel Travel - Front120 mm / 4.7 in92 mm / 3.6 in
Wheel Travel - Rear130 mm / 5.1 in82 mm / 3.2 in
Electronics
Electronics Package6-axis inertial platform, APRC suite which includes ATC (traction control, AWC (wheelie control), AEB (engine brake), AEM (engine map), ACC (cruise control) 5 Riding modes - (Road and Track, 3 fixed and 2 customizable)-
Wheels & Brakes
Brakes - Front2x 320mm Brembo radial calipers with 4 32mm opposing pistons. Radial pump and metal braided brake hoseSingle 320mm rotor, radially mounted, monoblock, 4-piston caliper
Brakes - RearSingle 220mm disc; Brembo calliper with 2 isolated ∅ 34mm pistons. Pump with integrated tank and metal braided hosSingle 260mm solid uniform expansion rotor, floating single piston caliper
ABSABS Cornering multimapStandard
Rims - Front-4.5 x 17
Rims - Rear-5.0 x 16
Tyres - Front120/70 ZR 17 Tubeless radials160/70TR17 73V Dunlop- Harley-Davidson Series, radial, GT503
Tyres - Rear180/55 ZR 17 (alternatively 180/60 ZR17) Tubeless radials180/70R16 77V Dunlop- Harley-Davidson Series, radial, GT503
Wheels-Aluminum cast, satin black
Wheels - FrontIn aluminium alloy 3.5 x17-
Wheels - RearIn aluminium alloy 5.5 x17-