The supermotard from Aprilia evolves with the sole objective of providing maximum riding fun. Dorsoduro 900 is born out of Aprilia's solid tradition in this motorcycle segment and it is a true thrill generator.A revamped twin-cylinder with 90 nm of torque combined with bar-setting chassis architecture enhances its distinctive characteristic as a fun bike Full multimap ride-by-wire, traction control and abs round out a technical package par excellence. Aprilia Dorsoduro is the fun bike par excellence. Born out of an ingenious intuition by Aprilia, it was built with the sole objective of providing the most possible road riding fun, drawing from the best characteristics of sport bikes and supermotards.
The design: balancing point between form and function
The Aprilia Dorsoduro 900 project places riding fun at the centre of its focus: for this reason, the superstructures are reduced to the minimum indispensable, as anything that is not essential for performance and maximum riding pleasure has been foregone. The technical elements, on the other hand, play a fundamental role, becoming a fundamental part of the design. It is not just the hand guards on the handlebar and the number plate on the front that highlight the close bond with the racing world. The shape of the centre area, the one that most involves the rider during sporty riding, also highlight the design created to achieve optimized and compact dimensions that allow the rider to find the right feeling straight away. Aprilia engineers achieved this result by designing a long and flat saddle, clearly derived from the sports world, capable of ensuring the most effective riding position at all times and allowing plenty of room for longitudinal movement.
The tail is one of the most representative aesthetic aspects of the Dorsoduro: sleek and slender, it also houses the double exhaust, a solution that allows for excellent proportional symmetry and weight distribution.
The frame and the cylinder head covers, painted red, are yet another sporty feature. Gritty finish combines with the new graphics in the brand new Adrenalinic Silver colour scheme.
New electronic management
Electronic engine management is now handled by the new and more powerful Marelli 7 SM ECU, the same hardware used on the V4 bikes from Noale, that dialogues with the new full Ride-by-wire electronic accelerator system, completely built into the throttle grip. This system allows even more accurate management of the fuel/air mixture and the injection throttle valve opening based on numerous parameters including engine speed, gearbox position, air flow (in quantity and speed), throttle grip and temperature, with great benefits in terms of smooth riding without opening/closing jerks, containment of harmful emissions and fuel consumption. The engine is, therefore, always able to distribute the ideal torque and provide the best acceleration, all to the advantage of a satisfying and fun ride. The system also allows a weight reduction of 550 grams compared to the previous Ride-by-wire that equipped the Dorsoduro 750.
Better performance from the revamp V-twin engine
Starting from the 750 cc 90° V-twin engine base, well-known and popular because of its character and reliability, Aprilia developed a new 900 cc unit with the goal of obtaining more torque and response at low and medium rpms for a thrilling riding experience. The Aprilia V-twin was therefore revisited in numerous details to achieve this purpose.
The new engine capacity was obtained by increasing the stroke from 56.4 mm to 67.4 mm and leaving the bore unchanged (92 mm). By so doing, maximum power now peaks at 95.2 HP at 8,750 rpm, but more important is the maximum torque value that goes from 82 Nm at 4,500 rpm on the 750 cc V-twin to 90 Nm at 6,500 rpm on the new 900 cc V-twin, a value that is truly at the top of its category. It should be noted that, despite the fact that maximum torque peak for the new 900 cc V-twin is reached a higher rpms, the torque curve is actually flatter and always higher than the 750 cc predecessor. This operation allowed for an increase in acceleration response and pick up, all to the advantage of riding fun, without limiting the proverbial reliability of the powerplant in any way, shape or form.
Although the architecture remains unchanged - 90 degree angle between the two cylinders, as well as a timing system with four valves per cylinder, dual overhead cam and liquid cooling - the new engine has undergone various changes: an important operation aimed at reducing friction was carried out on the pistons, completely redesigned and now characterized by a special anti-friction feature on the mantle, whereas new pins have led to a lightening of the alternated parts in motion. The crankshaft, also new, is balanced differently.
A new and more efficient semi-dry carter internal lubrication circuit reduces losses of power due to shaking and keeps consumption and temperature of the lubricant to a limit, thereby eliminating the need for an oil radiator. The engine also uses new injectors: improved fuel/air mixture spray achieved through the increase of fuel pressure benefits consumption and emissions, thereby contributing to the engine's compliance with the limits established by the Euro 4 emissions standard. This result is also achieved thanks to the exhaust system, fitted with a double oxygen sensor. The Aprilia Dorsoduro 900 engine is also fitted with an automatic decompresser which makes it easier to start in low temperature conditions.
The load on the clutch lever has decreased by 15%, all to the advantage of comfort with a clutch that has been completely revamped in all of its components, whereas the primary drive reduction ratio has been changed to optimize exploitation of the available power. Aprilia Dorsoduro 900 is also available in a limited-power 35 kW version, ideal for newly licensed riders.
Chassis architecture: better handling and control
All Aprilia bikes have always been considered a point of reference for their excellent chassis architecture. The Dorsoduro 900 chassis provides high characteristics of efficiency, balance, a tight ride and precision even in extreme track riding, but at the same time it is easy and intuitive for daily use. These qualities are the merit of the particular layout of its various elements.
The frame takes advantage of the know-how Aprilia has developed in racing competitions, drawing deeply from the experience gained on the mixed structures used in the Supermoto world championship. The trellis upper part in steel tubing (now painted red, like the saddle support frame) is combined with wide spread aluminium lateral plates using special, high-resistance bolts. The result is an extremely rigid and lightweight structure, the best solution for taking full advantage of the revamped capacity of the 900 cc V-twin, with an aesthetic impact that communicates light weight, extremely high technical content and Italian style. Another strongly distinctive technical feature is the lateral and inclined positioning of the shock absorber, a unit that is adjustable in spring preload and hydraulic rebound. This solution has created precious space for an optimum exhaust manifold layout, without having an impact on the length of the bike and without stressing the shock absorber thermally. The aluminium swingarm is sized to withstand the asymmetrical stress due to the lateral positioning of the shock absorber and it boasts the torsional stiffness and elasticity characteristics indispensable for precision at rest and the ride feeling in transitory stages.
On the Dorsoduro 900 a new Kayaba fork makes its début (combined with forged aluminium steering yoke plates), 450 grams lighter, adjustable in spring preload and better capable of withstanding the stress of sport riding and absorbing bumps on the road surface, providing control in aggressive riding and greater comfort for those more relaxed rides. The overall improved performance of both the Dorsoduro 900 suspension systems is also due to the new pair of three-split-spoke wheels, more than 2 kg lighter than those that equipped the Dorsoduro 750. Reducing the gyroscopic effect increases handling and acceleration, as well as providing benefits for suspension performance because of the reduction of unsprung masses.
The Dorsoduro 900's top shelf chassis structure is completed by a sport-derived braking system. The front end relies on radial 4-piston callipers and a pair of 320 mm steel floating discs, lightweight and capable of guaranteeing reduced braking distances and excellent modulability. The 240 mm rear disc is gripped by a single-piston calliper. Both the front and rear systems have metal braided brake lines derived from the aeronautic sector, which eliminate the annoying buffering effect of conventional lines and guarantee precision and resistance to force.
