Aprilia RS 660 2021

The RS660 is Aprilia's first new motorcycle in years, filling a gap in their sportsbike lineup between the RSV4 1100 and the RS50 and RS125. It also comes with a brand-new engine...sort of.

The liquid-cooled 8v, 659cc parallel twin is essentially the front half of the RSV4 and Tuono's V4 1100cc engine, with all of its high-performance capabilities intact. Of course, it has new casings and castings, but it's still a superbike lump at heart. CFD (Computational Fluid Dynamics), CAE (Computer Aided Engineering), and FEM (Finite Element Modeling) are used to design and produce intakes, combustion chambers, and internals (Finite Element Method).

Its new high-compression (13.5:1) cylinder head has been tweaked for more low- and middle oomph. Peak torque is 49 lb-ft at 8500 rpm, with 80 percent available at 4000 rpm and 90 percent available at 6250 rpm – ideal for real-world riding. The class-leading 99bhp @ 10,500rpm (or 94bhp for the A2 licence restrictable version) is enough to propel the RS660 along at a devilish rate of knots, especially given its light weight (just 183kg wet) and irregular firing 270° crank, which gives it the hard-edged rumble of a 90° V-twin when thrashing it.

The engine is angled forward in the frame to keep the heat away from the rider, and the bottoms of the double skinned fairing are engineered to accelerate air between the panels for better cooling.

But, unlike a superbike with so much power that you can't use more than a fraction of it on the road, the RS660's power isn't excessive, and it's this, combined with its comfortable riding posture, that makes it so easy to ride and get the most out of at regular speeds.

Aprilia's new parallel twin will power a new generation of Aprilia road bikes, starting with the new Tuono 660 naked and adventure-styled Tuareg, both of which will be released next year. So, how does the 660 stack up against the competition? The Aprilia RS660 is more powerful than the 67bhp Kawasaki Ninja 650 and the 80bhp Honda CBR650R, but not nearly as powerful as the 110bhp Ducati Supersport. However, the Aprilia is lighter. It's not as powerful as a ZX-6R, R6, or F3 675, but it's also a lot lighter.