Aprilia SR50

SR50 Factory
Manufacturer	Aprilia
Parent company	Piaggio
Production	2005 - Current
Class	Scooter
Engine	49.38 cc (several different engines used)
Top speed	approx. 90 km/h (unrestricted)
Transmission	CVT
Suspension	Front telescopic fork, rear hydraulic monoshock
Brakes	190mm disks front and rear
Tires	13" wheels 130/60 tyres
Wheelbase	1290 mm
Length	1860 mm
Width	705 mm
Seat height	765 mm
Wet weight	108 kg
Fuel capacity	7 l
Oil capacity	1.2 l
Fuel consumption	40 - 50 km/l average range
Turning radius

Aprilia SR50 R Factory, the latest model

The Aprilia SR50 is a family of sport scooters built by Italian motorbike company, Aprilia. Introduced in 1992 and considered to be the first "sports" scooter, the design and technology of the SR50 has evolved considerably over the years, although it has consistently used a 2-stroke 50cc displacement engine.

Design

With sports oriented suspension and tyres, and a more powerful engine than most 50cc designs, it is faster than many and more agile than most other scooters, consistent with its "sports" marketing. Sales of the SR50 have reached over 800,000 units, providing a stark exception to the trend in motorcycles since the 1990's for two-stroke engines to fade away. Through constant technology upgrades, the bike conforms to EURO 3 emission standards despite being a two-stroke.

Engines

The SR50 has made use of multiple engines since it's launch. At times it has been simultaneously offered with injected and carbureted versions, and different engines have been used in different markets at the same time. For example, jsut the Factory version alone (sold from 2005 onwards) has been offered in different markets with engines from Morini, Piaggio and Minarelli.

This scooter is very popular in European states, and so modifications are mass produced and prove very popular. In fully de-restricted form it can make for quick, cheap city transportation, whilst still achieving a top speed of around 50mph.

Laws vary from country to country regarding licensing and operation of 50cc scooters and mopeds.

Aprilia SR50

SR50 in Europe

Whilst commonly known as a Scooter (motorcycle), its power output is too high, so it is classified as a motorcycle under UK road laws. Due to recent laws (in the UK), restrictions have been added to stop people using these for racing. These restrictions include: restricting the variator (gears), restricting the carburettor, placing a restrictor bar across the bottom of the engine (to stop the installation of racing exhausts).

A de-restriction takes about 45 minutes to do using the right tools, or you can have it done at a garage (mechanics) usually for about £30–£40 each.

The SR50 ‘DiTech’ model, which costs £300 more than the carburettor version, uses an injection engine. DiTech is merely the name Aprilia gives to this engine, which is actual engineered and designed by Orbital. It is highly fuel efficient, achieving up to 100 miles per gallon.

SR50 in North America

In North America, the SR50 is considered a limited motorcycle as it has 50cc displacement and an automatic transmission. A motorcycle license is usually not required (though state and provincial laws vary) and can be registered/licensed/insured without a motorcycle license.

To sell these vehicles as "mopeds", the bikes are mechanically restricted when imported to approximately 48 km/h. However, the restrictions are easily removed using simple hand tools and a software programmer available at the dealership. Once de-restricted, top speed is 95 - 125 km/h. These speeds technically require a motorcycle license, however these are laws that are rarely enforced. Modifying the engine by enlarging the cylinder bore to anything greater the 50cc also technically requires a motorcycle license, but again this is something that is difficult to detect and seldom enforced.

Although there are several variant models of the SR50 worldwide, certain models are not available in certain parts of the world: the carburetor model was available just on a few models in the first few years of the SR50 since being introduced to North America. The large majority of North American SR50s are equipped with DiTech fuel injection, with models up to 2008 using the Aprilia (a.k.a. Morini) engine and 2009 and later models using the Piaggio engine.

External links

• 2009 SR50 R Factory at aprilia.com
• SR50 DiTech forums at apriliaforum.com
• SR50 Carburetor forums at apriliaforum.com
• Aprilia SR50 Parts Microfiche