Introduction

Aprilia - RX 50 (2003, ZD4STC) Racing

The Aprilia RX 50 Racing with type code ZD4STC was introduced in 2003 as a sport-oriented version of the RX 50 series. It was specifically aimed at young riders with off-road ambitions, combining rugged enduro technology with a dynamic look. As a successor to earlier RX models, it featured updated chassis geometry and model-specific design details. The "Racing" version included distinctive equipment features that set it apart visually and technically from the base model.

Model history

The RX 50 Racing (ZD4STC) appeared in the 2003 model year as part of Aprilia's comprehensively updated RX series. Typical for the Racing version were more aggressive graphics, often with special decals and matte or metallic color schemes. Minor technical differences, such as a different silencer, modified gear ratio or sportier suspension setup, were implemented depending on market and production series. Many owners used this model as a base for tuning projects or as an entry into amateur off-road competitions.

Technical details

Air-cooled single-cylinder two-stroke engine with 49 cc displacement and carburettor. Power output in derestricted form: approx. 7.0 hp at 9,000 rpm. 6-speed manual transmission with chain drive. CDI ignition, oil injection or premix depending on the version. Top speed in derestricted state: ~75 km/h. Fuel tank capacity: approx. 7 litres including reserve.

Chassis and brakes

Steel tube frame with bolted rear subframe. Front suspension with upside-down telescopic fork. Rear: monoshock with linkage and aluminium swingarm. Tyres: 21 inch front, 18 inch rear with knobby enduro tread. Brakes: 260 mm front disc, 180 mm rear disc. Some versions came equipped with braided brake lines as standard.

Colour variants

The RX 50 Racing was offered in special colour schemes such as black/red, blue/silver or yellow/black with sporty graphics. Wheel colour (e.g. black or white) and decals varied by market. Standard features included handguards, side stand and a sport-styled front mudguard. Popular accessories included racing exhausts, smaller sprockets, wider handlebars or off-road mirrors.