Do motorcycles always have to make sense? Or can they just be fun?
Flashback: at the 1994 IFMA motorcycle-show in Cologne Aprilia presents the RS 250 - a pure two-cylinder two-stroke rocket with the (revised) V 2 engine of the Suzuki RGV 250. Max Biaggi wins the first 250 cc Grand Prix World Championship title for the company of Ivano Beggio just on the last day of the fair. There was no better way to do a product launch, the RS 250 was a success story for Aprilia and turned many youngsters into racers who took part in the company’s trophy-races in the Nineties.
Today the situation is somewhat different: Aprilia was taken over by Piaggio at the turn of 2004/2005 and the RSV 4 presented in 2009 is still a reference for Supersport road bikes. After the decision to discontinue with the Shiver and the Dorsoduro as they would not comply with Euro 5, a huge gap would have remained between the RSV 4 and the RS 125 with the Piaggio four-stroke engine, which is based on a project of the Catalan subsidiary Derbi (closed down in 2011).
The concept of the RS 660 was presented at the Milan Motorcycle Show in the fall of 2018 but even if Piaggio's marketing department emphasizes that this was the official starting point of the project, at least the engine development team must have been active since 2017, as a completely new engine can hardly be ready for production in less than 3 years, given the demands of today’s emission and noise limits. The adoption of the cylinder heads and the bore dimensions from the big sister RSV 4 was certainly helpful in this respect to accelerate the project.
Press-launches have become some kind of Russian roulette these days and Aprilia is one of the very few companies that kept their nerve to pull through with the presentation near Bassano in Italy despite all the difficulties at the beginning of the second Covid-19 wave in Europe.
Bravo! Compliments for this and for the courage to revitalize a new category of vehicles that was always a tough one for Aprilia. At the end of the Nineties the R&D department, together with the former engine supplier Rotax from Austria, tried to gain a foothold in the hotly contested and extremely popular middle class between 600 and 800 cc.
However, the European project could not compete against the Japanese mass production technology at a competitive price, despite the takeover of standard parts from Rotax's range of snowmobile engines. Prototypes of naked- and adventure-bikes with a 800 cc V 2 engine were built but then stopped after the first tests in autumn 2001, also under the impression of the 9/11 disaster in New York and uncertain future markets.
Later, the Shiver 750 and the Mana 850 with the two-cylinder V-engine of the parent company Piaggio were introduced but the success of these machines was limited, even though the Mana was equipped with an interesting automatic transmission. The 90 degree V2 engine from Pontedera was never really an authentic Aprilia product like the 60 degree V 2 from Rotax or later the V 4 in the RSV 4 and Tuono V 4.
While the other Piaggio motorcycle brand Moto Guzzi is featuring attractive bestsellers like the V 7 and the V 85, some fans were starting to worry about the future of the Aprilia brand. Finally, the company is launching a new product which, both in terms of design and colour-scheme as a "Reggiani replica" clearly reflects the company's sporting DNA. The big surprise lies under the fairing though: the completely new developed two-cylinder in-line engine with 659 cc is something Aprilia has never had before!
The design of the bike was developed under Marco Lambri from the Piaggio design-department. In the "Center of Competence Motorcycle", Roberto Calò, who moved from competitor Cagiva/MV Agusta to Noale after the takeover by Piaggio, is responsible for the development of the complete vehicle. Franceso Mennella, who previously worked for a major automotive supplier in Bavaria for several years, has been recruited for the engine development.
The decision to develop a fully faired "Sport-Light" bike was taken after analysing the reasons that caused a 40 % loss of sales in the 600 cc Supersport class between 2010 and 2019: uncomfortable ergonomics, sharp power delivery, complex rideability and narrow range of use in everyday life and on normal roads. Over the same period, however, the smaller displacement category of sports bikes between 250 and 550 cc had grown by 150%, indicating that there was room for medium displacement machines with a sporty character and a wider range of uses. Important sales arguments for this bike were "wellness over fitness", usable engine power instead of peak power and cornering speed instead of top speed. This is particularly important for the growing markets in the Far East, where motorcyclists are more and more keen to ride stylish European brands.
Therefore, ambitious goals were specified in the profilebook: excellent rideability and handling thanks to the lowest vehicle weight in the segment, comfort and a relaxed seating position, a wide usable power-range with a lot of torque, electronic driving assistants and an innovative design including features from the race-bikes.
Engine
The two-cylinder parallel twin with 659 cc takes over the front cylinder head of the RSV 4 and retains the bore dimension of 81 mm. To increase the displacement, the stroke has been extended from 52.3 mm to 63.93 mm, still not quite a “stroker”, but the strategy to gain torque is clear. The 13.5:1 compressed twin reaches its maximum power of 100 hp at 10,500 rpm and the maximum torque of 67 Nm at 8,500 rpm. 80% of the usable torque is already available from 4000 rpm on, and the rev limiter kicks in at 11,500 rpm. To reduce vibrations, a 270° crankpin offset with irregular firing sequence is used, making the in-line engine similar to a V 2 engine in terms of performance characteristics and sound. With a balancer shaft in front of the crankcase, the first and second order inertia forces are eliminated while the first and second order inertia moments remain. The engine is controlled via Ride by wire technology, two throttle bodies with 48 mm diameter and intake valves with 33 mm diameter (exhaust 26 mm), the intake manifolds have been changed compared to the RSV 4. To reduce the frictional forces between piston and cylinders (in the range of 5-10%) the cylinder axis has been shifted 7 mm forward with respect to the crankshaft, this cylinder offset is well known from racing and is used for the first time at Aprilia. An oil cooler was omitted for weight reason, instead a heat exchanger is used under the oil filter mounted on the front of the engine. Shifting is done by a six-speed transmission with quickshifter and anti-hopping clutch, but unlike the RSV 4 it is not a cassette transmission. The total weight of the engine that is a stressed element taking over the supporting function for the flanged frame and the rear swing arm, is 57 kg and thus probably somewhat higher than a comparable engine which is designed as a pure built-in unit. Another novelty: the RS 660 engine is not produced at the Piaggio-factory in Pontedera, like all the engines after the Rotax-era, but at Aprilia's main plant in Scorzé. This makes the parallel twin the first real Aprilia motorcycle-engine ever!
Chassis
The focus for the vehicle development were ergonomics, slenderness and aerodynamics.
In terms of ergonomics, this means a compromise between supersport and touring bikes regarding the contact points between rider and the handlebars, seat and footrests. At 820 mm, the seat height is lower than on sports bikes, and the seat is also 4 cm narrower compared to the RSV 4, which should also guarantee smaller riders a safe contact with the ground. The aluminium rear frame is 16 mm narrower than on the RSV 4, and the footrests are also 36 mm closer together to allow the same leaning angle as on a super sports bike with comfortably lower footrest positions.
The painted dual beam chassis made of gravity die-cast parts of an aluminium-silicon alloy weighs 8.2 kg and has been optimized by topological CAE simulations. It is bolted to the cylinder head and to the upper gearbox housing. The swingarm, cast from the same material with 4.9 kg of weight, has no welds at all and is bolted directly to the engine housing. The Kayaba shock absorber, adjustable in spring preload and rebound, is conected to the main frame and works without linkage. In the front a 41 mm Kayaba upside-down fork is used, which is adjustable in spring preload and rebound, the compression adapts automatically to the selected rebound control. Cast aluminium wheels (3.56 kg front; 5.38 kg rear) carry 120/70-17 tyres at the front and 180/55-17 at the rear. Deceleration is achieved by a Brembo brake system with radially bolted brake calipers and discs with a diameter of 320 mm at the front and a 210 mm brake disc at the rear.
Interesting is the underfloor exhaust system, which is designed as a one-piece unit with a total weight of 6.2 kg. Different header diameters serve to optimise performance
The petrol tank has a volume of 15 litres, an LED headlamp with integrated indicators and cornering light illuminates the road ahead.
Aprilia is breaking new ground in terms of bodywork: the aerodynamics have been finalized in the wind tunnel of the University of Perugia. The double side panels are designed to create a venture-effect, which sucks out the hot air from the engine before it reaches the driver's legs.
The TFT display is well known from the Moto Guzzi V 85 and has a new graphic design. A great effort has been put into the vehicle electronics and the CAN BUS strategy: the new 11 MP control unit from Marelli is the basis for the new electronic age of the Piaggio Group. To this end, the clock frequency has been increased from 50 to 200 MHz and the flash memory from 1 to 4 MB. The number of pins is impressive: 144 instead of 80 as before! Of course the Aprilia RS 660 has all electronic driving assistants such as wheelie and traction control, cornering ABS, Quickshift and various Riding Modes (3 for the road, 2 for the racetrack). New to this model is the adjustable engine braking torque.
Declared total dry weight is 169 kg, the homologated curb-weight with 90% fuel on board is 183 kg.
From the end of October 2020, the first machines in the three graphic versions Lava Red and Apex Black (unique: red front wheel and black rear wheel) and Acid Gold (with two red wheels) will be delivered at a price of 11.050 € (Italy).
An accessory package is available for track use as well as for touring riders.
Testride
The ergonomics are suitable for riders of medium stature, with my height of 175 cm both feet have sufficient contact with the ground. The distance from the seat to the handlebars, which are mounted just on the upper triple clamp, also fits very well. The non-adjustable lever of the cable-operated clutch is on the taller side with low operating force. The same applies to the Ride by Wire throttle grip, which nevertheless offers a decent feedback. The ignition key (cheap hard plastic) is inserted in the fuel tank cover in front of the steering head, in cold condition the Aprilia starts immediately and surprises with a discreet mechanical noise that doesn't change much even when the clutch is pulled. Footrests, gear and brake levers are positioned right, the first gear engages clean and about 2000 rpms are enough to start moving in an unspectacular way. Upshifting is easy, downshifting when driving fast and sporty lacks a precise feedback on the lever. Finding Neutral is difficult with the cold engine, at operating temperature it’s a little easier.
The power delivery of the engine is jolt-free over the entire speed range, even when suddenly accelerating below 3000 rpm, the engine does not shake or stutter. The usable torque is available over a wide range and around 8000 rpm the parallel twin gives another power-boost and shoots the bike into the next turn. Sometimes, that makes you enter a turn slightly fast, but the brake system works very well and together with the Pirelli Rosso Corsa II tyres the Aprilia can be slowed down to the matching speed on a dime. On some test bikes the ABS on the rear wheel was too sensitive, maybe due to a soft frontend setting and the relatively low position of the handlebars which transfer a lot of weight to the front end under heavy braking. By the way, the handlebar ends are not adjustable and are bolted directly onto the cast upper triple clamp, this could cause unpleasant consequences in case of a harmless slide…
The handlebar switches are new and the unit on the left side is massive asking for a poor cutaway at the left side of the front fairing.
But the engine, together with the low weight of the machine, radiates enthusiasm! The usable rpm range is so wide that between 70 and 140 km/h the bike can be ridden in third, fourth or fifth gear without shifting gears. Depending on the gear selection, the sound goes from racing to touring. While the presentation video still gave rise to the suspicion that the sound of the V 4 might have been added to it, the deep guttural humming, especially from the intake system, has an addictive effect. In combination with subtle vibrations, the sound concert conveys an intensive and lively contact with the machine. When the throttle is released, fine vibrations can be felt in the footrests and tank at around 8000 rpm. The limits of the chassis could not be explored during the test ride over the Asiago plateau with temperatures in the 60° F range. If one nevertheless dared to deliberately open the throttle earlier at the exit of the turns, it was possible to understand the capabilities of this well-balanced chassis in order to push one's personal limits in complete safety.
The RS 660 immediately conveys a deep sense of confidence and reveals its character in the very first corners, making it easy to understand even for beginners. With the easy handling -appropriate to its class and weight- it carves through turns and turn-combinations of all kinds with extreme precision. The centre of gravity is positioned so perfectly that the bike can be thrown from one side to the other at the point. Once the line in the turn has been chosen, the engine pulls the sports machine through without load reactions, regardless of the gear. The suspensions absorb small and large bumps perfectly and the self-steering behaviour on pronounced longitudinal grooves is hardly noticeable.
The dynamic characteristics of the Aprilia RS 660 follow the infallible tradition of its excellent Noale predecessors. The test machines presented here were pre-series models, so there is still room for improvement in the finish before the first customer machines are delivered.
The true DNA and the pedigree of Aprilia sportsbikes, is revealed in an unspectacular way on the return journey through the plain south of the Venetian Alps: without particular load the engine purrs along at 3000-5000 rpm and for a moment it really feels like the good old 60 degree V2 of the RSV Mille pulsating between the knees. Those who have enjoyed that engine to the full can hardly escape its fascination and will let similar emotions run free on the RS 660.
Welcome back Aprilia! The values that made your bikes great still exist!