Highs and Sighs: 2026 Aprilia RS 660 Factory
Aprilia ushered in a new generation of middleweight sportbikes when it debuted the RS 660 in 2021. Aprilia found a new sweet spot, offering sportier performance compared to other middleweights on the market at the time, without sacrificing practicality like more demanding supersports. In the years since, we’ve seen new competitors adopting this formula, such as the Yamaha R7, Triumph Daytona 660, and Suzuki GSX-8R, enough so that the World Superbike Championship adopted a new World Sportbike class specifically for motorcycles like these.
Facing increased competition, Aprilia pushed the envelope even further, squeezing more power out of its Parallel-Twin engine, updating the fairings with a new aerodynamic winglet, and adding a new RS 660 Factory variant with upgraded Öhlins suspension.
We recently tested the 2026 RS 660 Factory and came away impressed with Aprilia’s vision of what a modern middleweight can be. Here now are three things we liked, and three areas where there is room for improvement.
Photos by: Nic de Sena
High: Ripping middleweight engine
We’ve long been fans of Aprilia’s V4 superbike engine, and that love’s carried over to the RS 660 Factory’s Parallel-Twin. Aprilia recently updated the 659cc engine to meet Euro5+, but the emissions standard hasn’t dulled its edge. On the dyno, we measured a peak output of 89.9 hp at 11,300 rpm, and 44.5 lb-ft. at 9,800 rpm, with power feeling even more linear than before, pulling from the get-go and through the midrange, and continuing to climb up until it reaches its 11,800 rpm redline.
High: Superb handling
The regular RS 660 impressed Troy when he first tested it at Chuckwalla Valley Raceway in 2022, and the Factory model improved on the already impressive handling, swapping out the KYB suspension with an Öhlins NIX 30 fork and STX 46 monoshock. A wider range of adjustability, and a beefier 43mm fork diameter helped keep the RS 660 Factory composed under braking and during acceleration, while providing more feedback than the standard model’s suspension. It also doesn’t hurt that the RS 660 Factory measured just 403 pounds, fully fueled, on our MO scales.
High: Easygoing ergonomics
While sporty in nature, the RS 660 Factory doesn’t force you into the clamshell position, instead putting you in a posture somewhere between a naked bike and a traditional supersport. The handlebars keep your upper body in an athletic pose, without feeling like your weight is being carried through your wrists. Most riders should find the pegs offer adequate legroom and the 32.3-inch seat height to be more approachable compared to more hardcore sportbikes.
Sighs: Cockpit could be tight for taller riders
You might have noticed the “most riders” caveat in the last point, as taller riders may have a different opinion. Pictured here, Road Test Editor Troy Siahaan managed to tuck all 5-feet 8-inches of himself behind the RS 660’s bubble, while anyone approaching 6 feet or taller will find the cockpit to be a tight squeeze.
Sighs: Emissions slump is still there (but improved)
While we counted the engine as a high, we did notice a bit of a dip in second gear, between 4,600 and 6,400 rpm. This isn’t unique to the Aprilia, as EPA noise restrictions cause many other bikes in the American market to do the same. An ECU flash should help with that, but Aprilia did a better job than most in counteracting this issue in stock form.
Sighs: Quickshifter can be sticky at low rpm
The RS 660 Factory comes equipped with a bi-directional quickshifter, but we found its performance to be a mixed bag. For sportier riding, it delivered clean, crisp clutchless shifts under load at high engine speeds, but for more relaxed riding, we found it clumsy at low rpms, and it needed a bit more effort than expected to shift gears.
