2012 Aprilia RS4 50

Even if the Aprilia RS4 50 belongs in one of the lightest classes in Moto GP racing, you can’t deny that the bike has produced some pretty amazing results in its short period of time.

When Aprilia decided to build the RS4 50, they did so while keeping in mind the recipe of a championship-winning bike. The livery and eye-catching form of the Aprilia RS4 50 echo the looks of the Factory version of the Aprilia RSV4 supersports, sharing more than just a family resemblance with the most hardcore street version bike dominating the world SBK championship.

The design of the fairings and tank, the unique looks of the front end, with the headlights suspended over the gaping air intakes, and the spectacular tapered tail fairing are identical to their counterparts on the V4 1000 cc supersports model that set new standards in terms of style and technical content for the superbike segment.

At the heart of the Aprilia RS4 50 is a single-cylinder 50 cc unit water cooled two-stroke with reed valve induction that comes mated to a six-speed transmission, allowing the rider to make full use of the performance of this class beating engine. This gives the bike the kind of championship-caliber performance that has defined Aprilia’s image as one of the best in the business.

Find out more about the Aprilia RS4 50 after the jump.

Engine

Aprilia RS4 50

With the new RS4 50 and RS4 125, Aprilia confirms its global leadership in the small capacity sports and young-targeted bike segment, creating models that exceed the expectations of even the most discerning rider.

The sophisticated chassis architecture of the Aprilia RS4 50 and RS4 125 is complemented by state of the art engines.

The single cylinder 50 cc unit developed by Aprilia for the RS4 50 is a water cooled two-stroke with reed valve induction. The lubrication uses a separate mixing system with a variable capacity volumetric pump. The six speed gearbox lets the rider make full use of the performance of this class beating engine.

The Aprilia RS4 is powered by an all new 125 cc water cooled 4 stroke single cylinder engine with four valves and electronic engine boasting a sophisticated double overhead camshaft (DOHC) valve timing system. This engine produces the maximum power output permitted for the class with a smooth, linear delivery and ecologically - as it meets even the strictest emissions regulations in effect.

With a six speed gearbox allowing the rider to make full use of the power available in all conditions, the Aprilia RS4 125 offers unbeatable performance in its class not just in terms of absolute power at high engine speeds, but also in terms of usable power band, minimized vibration and outstanding mechanical reliability.

Design

Aprilia RS4 50

The livery and eye-catching forms of the Aprilia RS4 50 and RS4 125 echo the looks of the Factory version of the Aprilia RSV4 supersports bike. And the RS4 shares more than just a family resemblance with the most hardcore street version the bike dominating the world SBK championship.

The design of the fairings and tank, the unique looks of the front end, with the headlights suspended over the gaping air intakes, and the spectacular tapered tail fairing are identical to their counterparts on V4 1000 cc supersports model that set new standards in terms of style and technical content for the superbike segment.

Extensive aerodynamic studies have minimized surface areas without compromising wind protection, and the fairings showcase the superlative mechanicals of the Aprilia RS4 50 and Aprilia RS4 125 rather than conceal them. As a result, the frame and engine are not hidden away but proudly flaunted as fundamental elements of the design of Aprilia’s new small supersports models. With the triple headlight, the Aprilia RS4 bikes have a decidedly aggressive look that lends a unique character to the entire front end.
The LED taillight merges stunningly into the ultra-compact tail fairing and offers excellent luminosity.

The fairing, product of extensive wind tunnel testing and race experience, offers excellent wind protection together with superb aerodynamic efficiency. And as well as contributing to the extremely aggressive looks of the bike, the top fairing and tail fairing also maximize performance in terms of speed. On Aprilia RS4 125, one additional detail underscores the level of sophistication of the bike: the exhaust, which is unmistakably inspired by competition machines, is completely integrated within the lower part of the fairing. A solution that is not just visually effective, but which also contributes significantly to the dynamics of the bike by helping to centralize masses.

Aprilia Quick Shift

Aprilia RS4 50

For the first time on a 125 bike, Aprilia offers the innovative Aprilia Quick Shift system, a sophisticated technical solution derived directly from the extraordinary big sister, RSV4 APRC, which in turn is derived directly from Aprilia’s experience in the World Superbike championship. The operational principle is similar, although partly simplified, to that of the RSV4: on the RS4 the system also guarantees torque interruption for gear change based on the speed which is engaged, the level of gas opening and the engine rpm, but for the 125cc, the shift time is a fixed parameter. The advantage of this system – available as a separate accessory - is that the rider can easily upshift keeping the gas open without using the clutch, thereby making the gear change simple and quick.

Chassis

Aprilia RS4 50

The chassis is without a doubt the feather in the RS4 project’s cap: built based on the exceptional experience which Aprilia has gained in WSBK and the 125 and 250 classes in Moto GP, it uses die cast aluminum spars with crossed reinforcement ribs. With its state of the art design, this extremely lightweight structure offers high torsional stiffness.
The front suspension also boasts a class beating layout, with a sturdy 41 mm upside fork, black anodized stanchion clamps and a wheel travel of 110 mm, while at the rear is a monoshock linked directly to the asymmetric swingarm.
Both the Aprilia RS4 50 and RS4 125 boast class beating brake systems: each bike uses a 300 mm steel disc at the front, gripped by a four piston radial caliper, and a 220 mm disc at the rear with a single piston caliper.
The 17” wheels are shod with 100/80 rubber up front and a 130/70 tire at the rear.

Equipment and Features

Aprilia RS4 50

The multifunctional analogue/digital instrument panel with LCD display draws directly from its big sister, the RSV4, while the design of the split 6-spoke design of the wheels further emphasizes the purposeful character of Aprilia’s latest small capacity sports bikes. The passenger saddle is yet another example of the extreme level of sophistication of these new bikes from Aprilia. Instead of fiddly screws, a practical quick release button allows the passenger seat to be exchanged with the tail fairing cover in an instant to transform the bike from two seat to single seat configuration (available as a separate accessory). Under the saddle there is also space for a practical glove-box, the most spacious in its category.

Specifications

Aprilia RS4 50
EngineSingle-cylinder, two stroke, carburetor, liquid cooled.
Bore x Stroke39.86 x 40 mm
Total displacement49,9 cc
Compression ratio11,5 :1
IgnitionElectronic with CDI capacity discharge
StartingElectric
LubricationAutomatic mixer
Gear box6 Ratios, 1st 11/34, 2nd 15/30, 3rd 18/27, 4th 20/24, 5th 22/23, 6th 23/22
ClutchMultiplate wet clutch
Primary driveGears, 21/78
Final driveChain, 11/53
FrameTwin spar aluminum frame
Front suspension41 mm upside down fork, wheel travel 110 mm
Rear suspensionAsymmetric swingarm with monoshock, wheel travel 130 mm
BrakesFront: 300 mm stainless steel disc with radial 4 piston caliper Rear: 218 mm stainless steel disc and caliper with single 30 mm piston
WheelsIn light alloy with 6 split spokes, with sealing profile for tubeless tires; front: 2.75 x 17"; rear: 3.50 x 17"
TiresFront: 100/80 - 17", rear: 130/70 - 17"
DimensionsMax. Length 1953 mm Max width 740 mm Max height at top fairing 1,138 mm Saddle height 820 mm Wheelbase 1,350 mm
Fuel tank capacity14.5 liters (including 3.5 liter reserve)
EmissionsEuro 2

Quotes

Total Motorcycle----"Aprilia has always drawn from this wealth of success and technical skills for mass production - both in the philosophy which inspires the product and the aesthetics which are often taken from the racing bike - establishing itself from the start as an absolute leader in the 50 and 125 super sport segment, categories in which the Noale brand has introduced timeless innovative concepts and solutions and dictating trends which would be followed by all of its competitors."

Zimbio----"APRILIA SPORT BIKES: WINNING DNAIn its short history, Aprilia has earned 48 world titles (37 in Moto GP, 2 in Superbike, 9 in off-road competition) and hundreds of championship races, to become the most victorious Italian and European brand in just a short period of history in Moto GP."


*Registration is required to post in this forum

Back to top