Hot new Aprilias heading for SA
Aprilia has announced four new products for 2007 - three of which will be coming to South Africa. The MXV450 motocrosser, 750cc Shiver (an appropriate name for a naked bike!), 850cc Mana and a new V4 superbike engine were first shown at the Milan bike show.
MXV450: This is the long-awaited motocross version of Aprilia's championship-winning 450 and 550cc V-twin supermotard and enduro machines.
It has the same SOHC, liquid-cooled, fuel-injected engine but without the electric start (saves weight) and a single, central radiator replaces the earlier dual units.
The steel frame with stamped aluminium engine plates is also retained, with slight changes in geometry to accommodate a longer-travel MX suspension that uses 50mm upside-down Marzocchis in front and a new tapered-section aluminium swing-arm, rising-rate linkage and re-valved monoshock at the rear.
It will be available in South Africa from mid-January 2007 - prices then.
SL750 Shiver: This is the first Aprilia to have an electronically controlled throttle controlling a new and very compact 750cc, 90 degree V- twin engine with dual-spark ignition for which Aprilia quotes 70kW, not far short of comparable four-cylinder naked bikes but with much more mid-range torque.
Its frame is a combination of aluminium castings and steel trellis carried on 43mm inverted Marzocchi forks and an off-set rear monoshock while braking is entrusted to Brembo radial mount callipers. Aprilia quotes a dry weight of 189kg.
The Shiver will be available in South Africa from the second quarter of 2007. Prices ditto.
850 Mana: This model has a computer-controlled CVT transmission with three mappings invoked by a button on the handlebar switches - touring, sport or rain - or it can be ridden as a seven-speed manual sequential shift, either push-button or foot-actuated.
The engine is an 850cc, 90-degree V-twin with electronic fuel-injection and dual-spark ignition, same as the Shiver.
It has a steel trellis frame and a similar suspension and braking set-up to the Shiver.
The fuel tank has been moved to beneath the saddle and there's a storage compartment big enough to hold a full-face helmet where it would usually be.
The Mana will be released in South Africa in mid-2007; prices then.
Aprilia's first four-cylinder engine was developed for of superbikes in the near future. It's the company's most powerful engine yet at more than 155kW in racing trim and revving to 13 500.
After considerable testing the V angle was set at 65°, almost the same as the company's existing big V-twins, allowing the designers to use Aprilia's wealth of experience in chassis design.
The narrow-V makes the engine very compact and keeps the bike's masses central. It also permits the best suspension geometry with a long swing-arm inside a short wheelbase.
A lateral cam chain in each cylinder head drives only the inlet cam, following the ideal drive path for precision valve timing and extended chain life, while a pair of gears between the cylinders takes the drive to the exhaust cam.
A balance shaft reduces primary vibration to less than that of a 90º V and all four cylinders are housed in a single casting (it's the upper half of the crankcase) with liners for maximum rigidity and efficiency.
There's no direct connection between the twist grip and the throttle bodies; the butterfly valves are controlled by a Marelli engine management unit.
Each pair of cylinders has its own throttle-body servomotor and the front and rear cylinders can be independently mapped.
The fuel-injection system uses two injectors per cylinder, one downstream of the throttle butterfly and one in the air box that cuts in under high load and high speed.
The transmission has a cassette gearbox, wet sump and wet slipper clutch.
Layout: 65° fourstroke V-four.
Engine body: Monoblock with liners integrated in crankcase
Compression ratio: 12.5:1
Valve gear: DOHC with four valves per cylinder.
Power: More than 155kW at 13 000rpm in racing configuration.
Fuel system: Electronic fuel-injection with two injectors and independent electric control for each row of cylinders.
Clutch: Wet multiplate with slipper system.
Gearbox: Six-speed cassette.