The Ducati ST4S was a sport-touring machine introduced in late 2001 and available in 2002. The bike was part of the ST series that debuted in 1997, which comprised five models with similar appearances but different engines.
Compared to the standard ST4 model, the Ducati ST4S version was fitted with an improved suspension system that improved handling and a slightly larger engine that delivered more power and torque.
In 2004, the ST4S was revised with modified front fairing, dashboard, adjustable ergonomics, a trip computer, four-way hazard flashers, a digital speedometer, an adjustable headlight controlled from the dashboard, a new seat design, a EURO2 catalytic exhaust system, and a more simplified CAN-bus wiring system, which reduced the overall weight by 11 kg (24 lbs).
The 2005 Ducati ST4S was fitted with standard features, such as a full fairing, a single-piece dual seat with a passenger grab handle, a dual exhaust system, five-spoke lightweight alloy wheels, and optional side-mounted panniers for more storage.
At the bike's core was a 996cc four-stroke liquid-cooled V-twin engine fed by an electronically controlled fuel injection system, delivering an output power of 117 hp with maximum strength at 8,750 rpm and 98 Nm (72 lb-ft) torque at 7,000 rpm.
The 2005 Ducati ST4S was fitted with a six-speed manual transmission, a hydraulically controlled wet multi-plate clutch, and a final chain drive, spinning the rear wheel to a top speed of 237 kph (147 mph).