The Aprilia RS125 is a GP derived replica sport production motorcycle. It is powered by a Rotaxsingle cylinder 124.8 cc two-stroke engine with Nikasil coated aluminium cylinder block, and liquid cooling. The top speed is 170 km/h and the acceleration takes 6.5 sec. The speed depends on the weight of the driver. Aprilia has had many Grand Prix victories in the 125 cc and 250 cc two-stroke classes. This racing experience has been used by Aprilia to produce updated and improved versions of the RS125.
The RS125 is revised and the Extrema wording is dropped. The RS retains a lot of the appearances of the previous RS but there are some notable differences. The first one is a new engine, the Rotax 122, a new improved version to the previous one. The front air intakes are integrated into the front upper portion of the middle fairing. The headlight unit is rounded and the lip is introduced to the top centre. A digital gauge is added in place of the temperature gauge.
RS125 1999 to 2005
The RS125 was revised again in 1999 with more rounded and bulbous fairings, five spoke rims and a single air duct on the driver's right hand side. The lip on the headlight unit is increased in size.
RS125 2006 to 2012
The RS125 was given completely new fairing styling similar to the RSV 1000R. The most notable features are the angular fairings, two headlight units, digital gauge and multispoke Marchesini-styled rims. The bike's brakes have also been upgraded, featuring a radial four-piston brake caliper and braided brake lines. In 2008, the bike's electronics were changed from Nippon-Denso to Piaggio/EFI Technology electronics, most notably the new ECU to meet the more stringent EURO3 Emissions standards. The bike has also been fitted with a vacuum fuel tap on the tank and a new Dell'orto 28 mm VHST carburettor that features the vacuum pipe extension. The line was dropped in 2012 to make way for the new RS4 125, going from a two-stroke to a single-cylinder four-stroke fuel injected system.
Tuono 1999 to 2005
The RS125 Tuono was introduced in 1999 as a semi naked version of the RS125. Production ran until 2005 and was subsequently dropped from the line-up. The Tuono was essentially an RS125 with the middle and lower portions of the fairings absent and a handlebar fitted on the top yoke.