Aprilia, the Italian motorcycle manufacturer owned by the Piaggio Group, has produced the RS 125 since 1995, selling it to new riders as a great bike for learners who love speed. However, 2009 was the first year the model was sold in the United States. That year Aprilia exported a limited number of the bikes to America. These machines were strictly for use on the track; they did not meet U.S. emissions standards, and so they could not be licensed for street use. The 2009 RS 125 was a replica of the 2009 Grand Prix winner, which Spain’s Julian Simon rode to the championship, complete with ""Spain’s No. 1"" emblazoned on the red-and-yellow racer.
Powered by a 124.8cc, liquid-cooled, single-cylinder, two-stroke engine made by the Austrian company Rotax, the 280-pound (dry) bike has a reed valve configuration and a Dell’Orto carburetor. It has a six-speed manual transmission and a chain final drive. An inverted fork with 4.72 inches of travel provides the front suspension; the rear is a twin-sided swing arm with a single adjustable spring preload shock. Stopping power comes from a single, radial-mounted four-piston caliper hydraulic disc in front, with a single two-piston caliper disc in back.
Despite the fact that the bike, as produced, is not street legal, it comes equipped with all the accoutrements of a street bike: dual headlights, taillights, and a horn, along with such standard instrumentation as a speedometer, tachometer, and odometer, probably because this same bike has been popular with teen street riders in Britain and Europe for a long time. There is no gauge to tell you how much fuel is in the 3.7-gallon tank, but that’s not the sort of thing you expect from a sport racer.
What you do expect is handling, and here the RS 125 truly shines. Riders comment on its responsiveness and the speed with which it corners and how much fun it is to ride as you lean into turns. Although it is a small machine, taller riders don’t feel cramped while riding.
The Rotax engine requires special maintenance, and there have been complaints about reliability, with a number of owners mentioning that the engine simply seizes without warning, despite meticulous maintenance. Even those who adore the RS 125, and many do – Aprilia has sold close to 100,000 of these bikes over the years – acknowledge that it requires careful warming up and attention. In sum, it is a very cool-looking little machine that appeals especially to teen riders.