2021 Aprilia RS 660 vs 2026 KTM 990 RC-R

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
2026 KTM 990 RC-R 2026 KTM 990 RC-R

Sport

Engine
Four stroke, parallel twin cylinder, DOHC, 4 valve per cylinder
Power
128.2 hp / 94.3 kW @ 9500 rpm
Top Speed
N/A
Weight
195 kg 430 lbs
Full Specifications
General
Year20212026
Make ModelAprilia RS 660KTM 990 RC-R
Dimensions
Seat Height815 mm / 32.0 in845 mm / 33.3 in
Wheelbase1370 mm / 53.9 in1481 mm / 58.3 in
Ground Clearance-163 mm / 6.4 in
Weights & Capacities
Dry Weight (kg)169-
Wet Weight (kg)183 195
Dry Weight169 kg / 372.5 lbs-
Fuel Capacity15 Litres / 3.9 US gal15.7 litres / 4.1 US gal
Wet Weight183 kg / 403.4 lbs195 kg 430 lbs
Performance
Max Power100 hp / 73.5 kW @ 10,500 rpm128.2 hp / 94.3 kW @ 9500 rpm
Max Torque67.0 Nm / 6.83 kgm @ 8,500 rpm103 Nm / 75.9 lb-ft @ 6750 rpm
Engine
Displacement659 cc / 40.2 cu-in947 cc / 57.8 cu-in
Engine DetailFour stroke, forward facing parallel twin, DOHC with silent chain drive on the right side, four valves per cylinderFour stroke, parallel twin cylinder, DOHC, 4 valve per cylinder
Bore x Stroke81 x 63.93 mm92.5 x 70.4 mm
Compression Ratio13.5: 113.5:1
Cooling SystemLiquid cooled with radiator and water-oil heat exchangerLiquid cooled with water/oil heat exchanger
EmissionsEuro 5 CO2 emissions - 116 g /kmEURO 5+
Engine Management-Bosch EMS with RBW
ExhaustAkrapovič - for race use only-
Fuel InductionAirbox with front air intake. 2 ∅48 mm throttle bodies, Ride-By-Wire management46mm DKK Dellorto throttle body
LubricationWet sumpForced oil lubrication with 2 oil pumps
StarterElectricElectric
Drivetrain
ClutchWet, multi-plate, slipperPASC slipper clutch, cable operated
Final DriveChain, with drive ratio: 17/43Chain 520 X-ring, 16:43
Primary Drive-42:76
Transmission / Drive6 Speed, AQS Aprilia Quick Shift6-Speed
Chassis
Frame TypeDouble beam aluminium frame with detachable rear seatChromium-Molybdenum-Steel frame using the engine as stressed element, powder coated
Suspension - FrontKayaba upside down fork ∅ 41 mm with counter spring, aluminium feet for fixing radial calipers. Adjustable for rebound, compression and spring preload.WP APEX 48, open cartridge, compression & rebound (30 Clicks), preload (3 clicks)
Suspension - RearAluminium swingarm with asymmetrical trusses. Monoshock with adjustable counter spring: rebound and spring preload.WP APEX - Monoshock, compression high-speed (3 turns) low-speed (30 clicks), rebound (30 clicks), preload (10 turns)
Rake24.1°-
Trail104.6 mm-
Wheel Travel - Front120 mm / 4.7 in147 mm / 5.8 in
Wheel Travel - Rear130 mm / 5.1 in134 mm / 5.3 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 hose2 x 320mm discs, radially mounted 4 piston caliper
Brakes - RearSingle 220mm disc; Brembo calliper with 2 isolated ∅ 34mm pistons. Pump with integrated tank and metal braided hosSingle 240 mm disc, single piston caliper
ABSABS Cornering multimapStandard
Tyres - Front120/70 ZR 17 Tubeless radials120/70-ZR 17
Tyres - Rear180/55 ZR 17 (alternatively 180/60 ZR17) Tubeless radials180/55-ZR 17
Wheels-Cast aluminium
Wheels - FrontIn aluminium alloy 3.5 x173.5 x 17
Wheels - RearIn aluminium alloy 5.5 x175.5 x 17