The Aprilia SR 50 is a scooter built by Aprilia from 1992 to 2020 and considered one of the first to bring the idea of the “sporty” scooter to the market. More than 800,000 units were sold, against the trend away from two-stroke engines.
Aprilia SR 50 at a glance
| Production | 1992–2020; introduced in November 1992 |
|---|---|
| Sales | more than 800,000 units |
| First engine | vertical air-cooled single of 49.3 cc, electric start or kick starter |
| Engine makers | Morini, Piaggio and Minarelli |
| Claimed firsts (Aprilia) | 13 inch wheels, liquid cooling, double disc braking and a direct-injection engine on a scooter |
| Series | first 1992, second 1997, third with Piaggio engine from 2003, fourth at the end of 2004 |
| Emissions | Euro 3 |
| Top speed derestricted | 90 km/h (English Wikipedia) |
English and Italian Wikipedia agree on the main dates and facts above.
History of the Aprilia SR 50
The SR was introduced in November 1992 and opened the way to the sporty scooter, able to reproduce motorcycle emotions. The solutions of the first series were advanced, from the front disc brake to the telehydraulic fork, with colours inspired by Aprilia racing bikes. The first engine was a vertical air-cooled single of 49.3 cc with electric start by a button on the handlebar or a kick starter. Over the years it also got a horizontal Minarelli engine, air or liquid cooling, and a front disc with a rear drum. The Replica versions carried graphics dedicated to Aprilia riders of the time, among them Loris Reggiani, Max Biaggi (250 world champion in 1994, 1995 and 1996) and Doriano Romboni.
Second series, 1997
The second series had a deep restyle: the square lines were dropped for more aerodynamic and round ones, with a horizontal Minarelli engine available air- or liquid-cooled and a rear disc brake on the liquid-cooled version, plus a Showa telehydraulic fork. In 2000 there was a light facelift: white turn signals, a new nose and rear mudguard and a new instrument panel.
DiTech
The most important novelty was the electronic fuel-injection engine, which Aprilia called DiTech: a solution until then used only in cars that reduces consumption and pollution and improves performance. The SR50 DiTech uses the Synerject gasoline direct injection (GDI) system developed by Orbital Corporation and Siemens AG: a crank-driven compressor delivers air to the cylinder head at 5 bar, so there is no carburettor and only lubricating oil, not petrol, wets the cylinder walls. English Wikipedia says that humidity in the compressor system caused condensed water and that Aprilia added a retrofit solenoid valve to drain it. In 2003, after many problems reported by owners with the injection engine (Suzuki-Morini, built by Aprilia), all injected SRs got the Piaggio injection engine, already used on the Piaggio NRG and Gilera Runner.
Fourth series, 2004 onward
At the end of 2004 the fourth series arrived, the result of an investment of over 1.3 million euros, with an all-new design, new instruments with an on-board computer showing range, average speed and consumption, and halogen headlights. A carburettor engine stayed in production on the third series, now called SR 50 Street. In 2006 the special 50 R and 50 R Factory versions debuted, and in 2010 the Replica special edition came back. The SR left production in 2020.
Design and features
- Chassis: 13 inch wheels, double disc brakes and performance-oriented suspension and tyres.
- Instruments: a digital panel with speed, clock, odometer, trip counter, fuel level, coolant temperature and battery voltage.
- DiTech: direct-injection two-stroke engine that avoids carburation.
- Engines: from Morini, Piaggio and Minarelli; the current model uses a Dell’Orto carburettor.
Aprilia SR 50 versions
- SR 50 first series (1992): square lines, Minarelli engine, Replica graphics.
- SR 50 second series (1997): round lines, rear disc on the liquid-cooled bike.
- SR 50 DiTech (2000–): direct-injection two-stroke.
- SR 50 fourth series (2004), SR 50 Street, 50 R and 50 R Factory (2006).
- SR Replica (2010).
More Aprilia scooters are in our Aprilia collection, for example the Leonardo, the Scarabeo and the Rally.
Aprilia SR 50 questions and answers
When was the Aprilia SR 50 introduced?
In November 1992.
How many SR 50 were sold?
English Wikipedia says more than 800,000 units.
What is DiTech?
Aprilia’s name for the direct-injection two-stroke engine of the SR, using a Synerject system developed by Orbital and Siemens.
How fast is the SR 50?
About 90 km/h in its standard configuration once derestricted.
When did the SR end?
In 2020.
Video: Aprilia SR MHR Team 2 BigBore
Video by König Arci on YouTube.
Sources
- Aprilia SR50, English Wikipedia: history, DiTech engine
- Aprilia SR, Italian Wikipedia: series, replicas, updates
