TOP NOTCH LIGHT WEIGHT AND CHASSIS ARCHITECTURE, AS PER APRILIA TRADITION, FORM MAXIMUM FUN.
The Tuono 660 chassis architecture was developed with the goal of achieving the same levels of fun and effectiveness in sport riding that made the Tuono V4 famous, with a more street and daily-rider connotation to make Tuono 660 accessible and usable by a broader audience. An easy ride and a good feeling are guaranteed by an entirely new structure focused on light weight made up of a frame and swingarm that are both in exceptionally high-quality die cast aluminium. Compared to the RS 660, from which it is derived, the Tuono 660 chassis architecture boasts measurements that reward maximum agility, thanks to a wheelbase of 1370 mm and the 24.1° inclination of the headstock, further emphasized mounting steering plates with different offsets. Handling and quickness in direction changes increase, making the difference on those routes with corner after corner, combined with characteristics of bar-setting precision and feeling with the front end.
The frame is made up of two lateral spars bolted in the headstock area and in the rear part; the engine is used as a bearing element and contributes to forming a compact and lightweight structure. Unlike the RS 660, there are two frame anchor points to the engine (three on the RS 660): this allows for much easier and more predictable behaviour on the road, in line with the project goals that do not hide the vocation of being a sport bike accessible to a vast audience.
In order to make the structure light and minimalist, the swingarm is pivoted directly in the engine: it is a monobloc element characterized by its significant length, handy for outstanding traction and asymmetrical arms, a typical technical choice in the history of Aprilia sport bikes. The particular mounting of the adjustable shock allows for excellent progression even without linkage, for further important weight savings.
The chassis architecture is completed with an adjustable upside-down Kayaba fork with 41 mm stanchions and a braking system comprising, at the front end, a pair of 320 mm steel discs, a pair of radial callipers and a radial master cylinder on the handlebar, all by Brembo. Tuono 660 is shod with high performance Pirelli Diablo Rosso Corsa II tyres, 120/70 ZR 17 at the front and 180/55 ZR 17 at the rear, capable of guaranteeing safety and fun on the road, as well as all the grip needed for top performance on the track. The handling, light weight and compact dimensions of the Tuono 660, combined with its engine performance, result in great fun on those routes with corner after corner and, at the same time, they make it easy to manage the bike in an urban setting and in manoeuvres when stopped.
THE BEST WEIGHT/POWER RATIO THANKS TO THE NEW 95 HP TWIN CYLINDER. Aprilia Tuono 660 has a newly designed engine, already installed on the RS 660 and destined to equip a full range of new bikes. It is a 660cc forward-facing twin-cylinder, a latest generation, very compact unit that emulates concepts and measurements of the Aprilia V4 1100 cc engine front bank.
This configuration was chosen for its compact dimensions and light weight. An engine with reduced horizontal and lateral bulk allows for great design freedom both in terms of arranging all the fundamental organs such as the intake and the exhaust, and in terms of the chassis architecture. The engine also has a bearing function and the aluminium swingarm is pivoted in its rear area.
The forward-facing configuration provides comfort for the rider thanks to the better heat dissipation and it leaves the designer freedom in exploiting the spaces. Furthermore, this architecture lends itself well to cooling, thanks in part to the fairing’s ingenious double-wall system, the objective of which is precisely to accelerate the air that flows through it. With this same goal in mind, the long exhaust manifolds were developed, which emerge into a single-piece silencer with asymmetrical doubled output, fully positioned below the engine, with the further advantage of distributing the weight better and lowering the centre of gravity.
The Aprilia twin cylinder is the child of experience accumulated on the ultra-powerful engine that equips the RSV4, so it rests on a base that is extremely efficient, not to mention tried and true: head, combustion chamber, ducts, cylinders and pistons derive from the V4. The bore is also 81 mm, like in the 1099 cc V4, whereas the stroke is 63.9 mm. The decision to use the technology of the V4 guarantees outstanding performance, also considering the high stroke speed of the piston relative to the actual displacement.
The engine crankcase is cut horizontally into two pieces with the cylinders built into the upper semi-crankcase to reduce bulk and make the structure more robust. The cylinders are offset with respect to the crankshaft in order to minimize internal friction during piston thrust.
The camshafts of the double timing, 4 valves per cylinder controlled by a lateral chain are hollow and use the bucket tappets to move the valves. The multi plate wet clutch with mechanical control has an anti-juddering system.
The wet sump lubrication includes an oil sump protruded downward and made around the suction intake in order to better collect the lubrication in any riding phase, even when the bike is at maximum lean angle or in the braking and acceleration phases.
The resulting performance is the best of any twin cylinder up to 750 cc: 95 HP at 10,500 rpm, with a peak speed that has allowed the limiter to be moved to a threshold of 11,500 rpm. The maximum torque of 67 Nm is provided at 8,500 rpm, with 80% of it available from 4,000 rpm, which turns into 90% when you hit 6,250 rpm. Tuono 660 is also available in a 35 kW reduced-power version, ideal for newly licensed riders.
In addition to performance and light weight, another design objective was to obtain the character and aggressiveness from the engine typical of V-twins. In order to achieve this, timing with crankpins arranged at 270° was chosen. This means that combustion is asymmetrical and offset 270° to obtain irregular combustion which translates into performance and sound similar to a V-twin. Furthermore, this type of configuration allows easy balancing of the alternating first and second level forces, using a single countershaft. The injection system includes a pair of 48 mm diameter throttle bodies with different length intake ducts to optimize distribution at high and medium speeds.
The new engine’s performance is guaranteed by complete electronics, taken directly from those of the Aprilia V4, which includes an electronic multimap Ride-by-Wire throttle, for precise acceleration, soft and progressive even from low rpm, and optimized fuel consumption.
