In 1999, the Italian motorcycle manufacturer launched the Ducati ST4, a bike part of the ST series that debuted in 1997, with the ST2 as the first member of the family. The ST range comprised five models with different engines and designations but similar appearances.
The 1999 Ducati ST4 packed a four-valve Desmoquattro engine derived from the Ducati 916 model but was retuned for it to be used on the ST4 machine. After the ST4 release in 1999, the maker started to phase out the production of the 916 engine, which was last used on the 2003 ST4 model.
In the visual department, the 1999 Ducati ST4 packed the same standard features as the other ST model, including a full fairing with integrated turn signals, a windscreen, and a single headlight unit, a one-piece dual seat with a passenger grab handle, a dual exhaust system, and three-spoke aluminum wheels.
The bike's suspension comprised a 43 mm fully adjustable upside-down Showa fork on the front and a fully adjustable Sachs shock absorber with progressive linkage on the rear, delivering excellent handling capabilities.
The 1999 Ducati ST4 had at its core a 916cc four-stroke V-twin liquid-cooled engine with an Electronic Fuel Injection (EFI) system in charge, boasting 105 hp with a peak force at 9,000 rpm and 89 Nm (66 lb-ft) torque at 7,500 rpm.
The bike's power was handled by a six-speed manual transmission with a wet multi-disc clutch and a final chain drive that spun the rear wheel to 251 kph (156 mph).