The Ducati ST series represents a collection of Italian sport touring motorcycles produced by Ducati from 1997 to 2007. This lineup included five unique models, released sequentially: the ST2, ST4, ST4S, ST3, and ST3S. Designed to rival other sport-touring machines like the Honda VFR, the ST models featured a full fairing, a spacious dual seat, and a comfortable riding posture for both the rider and passenger. Each bike came equipped with a center stand and the option for matching luggage.
While the five models in the ST series shared a common aesthetic, including the same frame, bodywork, and cycle components, they were powered by distinct engines — all of which were liquid-cooled desmodromic V-twins. The number following "ST" (2, 3, or 4) indicated the valve count per cylinder. True to Ducati's design philosophy, the frames were constructed from tubular steel trellis, complemented by conventional suspension featuring upside-down forks and a rear monoshock. In 2004, the series underwent a facelift, receiving an updated front end, a new headlight design, the addition of ABS, and a reduction in weight.
The ST series debuted in Europe in 1997, with models reaching the United States by 1998. The inaugural model, the ST2, was powered by a 944 cc Desmodue two-valve engine. It replaced the Paso model and marked Ducati’s more concentrated entry into the growing sport-touring segment.
In 1999, Ducati expanded the lineup with the ST4, which featured the four-valve Desmoquattro engine derived from the iconic Ducati 916, albeit retuned for the sport-touring category. Following the introduction of the 996 Desmoquattro superbike later that year, Ducati began phasing out the 916 engine, with its final use in the 2003 ST4.
By late 2001, Ducati introduced the ST4s, equipped with the 996 Desmoquattro engine, which benefited from improved suspension and became available in 2002.
In 2004, both the ST2 and ST4 were discontinued and replaced by the ST3, which featured a new three-valve Desmotre engine with a displacement of 992 cc. The Desmotre engine required less maintenance compared to the ST4s, which had a reputation for high upkeep costs. Despite this, the ST4s remained the flagship model of the series.
Production of the ST4s ceased in 2006, giving rise to the ST3s variant that incorporated the advanced suspension components from the ST4s while retaining the unchanged ST3 Desmotre engine. The discontinuation of the ST4s was attributed to the 996 engine's inability to meet the stringent Euro-3 emissions standards, a hurdle the ST3 motor successfully cleared. In 2005, many models, including those in the ST series, received a wet clutch, which reduced the effort needed to engage the clutch.
Both "S" models, the ST4s and ST3s, could be fitted with ABS starting in 2003. The 2004 update to the ST line introduced enhancements such as a redesigned nose fairing and 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 Euro-2 compliant catalytic exhaust, and a streamlined CAN-bus wiring system. The dry weight of the bikes was reduced by 11 kg due to the lighter wiring harness and simplified nose support structure.
The ST series came to a close in 2008, with the ST3 and ST3s models collectively selling only 1,011 units worldwide in 2007. Following these disappointing sales figures, Ducati decided to shift its focus back to sport bikes, such as the Panigale. In its factory plan for 2008-2010, Ducati declared that it would no longer pursue the sport touring market.
Ducati ST2 (1997-2003)
The Ducati ST2 was produced from 1997 to 2003, designed specifically for touring with accommodations for two riders and enhanced wind protection provided by its full fairing. As a sport touring motorcycle, the ST2 distinguished itself with hard luggage, a more relaxed riding position compared to traditional sport bikes, and a robust engine that outperformed standard touring motorcycles. Its frame features a tubular trellis design, closely resembling the torsional rigidity and lightweight characteristics of the Ducati 916 frame.
Ducati ST 2, 1997 year, left view
Powering the ST2 is an engine derived from the 907 Ducati Paso, featuring Ducati's hallmark 90° V-twin (or L-twin) configuration with a single overhead cam (SOHC) and two-valve desmodromic heads. The engine produces a claimed output of 83 horsepower at 8,500 rpm, and it is equipped with Remus exhausts, a compression ratio of 10.2:1, and Weber-Marelli electronic fuel injection, utilizing one injector and one spark plug for each cylinder. The engine's displacement is increased to 944cc, and it features a heavier flywheel, making it well-suited for touring applications.
Ducati ST 2, 2003 year, right view
The suspension system on the early production models is fully adjustable, incorporating upside-down Showa forks at the front and a Sachs rear shock absorber, both of which are shared with the Ducati 916 Superbike but are tuned with softer damping characteristics for enhanced comfort. The ST2's braking system features dual 320 mm floating Brembo discs and four-piston calipers at the front, while the rear is equipped with a single 245 mm Brembo disc and a twin-piston caliper. The original equipment tires are either Michelin Macadam or Metzeler MEZ4 sport radials, sized 120/70 ZR17 for the front and 170/60 ZR17 for the rear, mounted on Brembo wheels.
Ducati ST4 and ST4s (1999-2005)
The Ducati ST4 was produced from 1999 to 2005 and featured a modified version of the iconic Ducati 916 engine.
Both variants of the ST4 utilize detuned superbike engines, with the standard ST4 equipped with a 916cc engine that delivers 107 bhp and 89 Nm of torque. The higher-spec ST4S boasts a 996cc engine, generating 117 bhp and 98 Nm of torque. While the engines can feel somewhat rough at low RPMs — requiring careful clutch management — once the bikes are up to speed, the smooth power delivery of the desmo V-twin aligns perfectly with the demands of sport touring. Both models offer abundant midrange power, allowing them to achieve peak performance before reaching 9,000 rpm, eliminating the need for high-revving antics. Some riders may notice vibrations typical of a V-twin engine; however, these are generally mild and can be mitigated by installing heavier bar end weights if desired.
Ducati ST 4, 2000 year, front view
Ducati has always prioritized sporty performance in their sport touring offerings, and the ST4 models excel in handling. Both the standard and S versions are equipped with fully adjustable Showa forks, with the S variant featuring a titanium nitride (TiN) coating for improved performance. The ST4S also comes with an Öhlins rear shock, while the standard model is fitted with a Showa shock, both of which are fully adjustable. Although the frame color was updated in 2000, its geometry remained unchanged. The ST4 shines in twisty roads, providing a rewarding mid-corner stability, although it may feel slightly sluggish in tight turns. Like many Italian motorcycles from this era, the suspension is initially set too stiff, but this can be easily adjusted. It's worth noting that the standard Showa shock is not rebuildable, while the Öhlins unit on the S version can be serviced, meaning a replacement shock could cost around £400 if damping performance diminishes.
Ducati ST 4S, 2004 year, left view
While the ST4 may not be ideal for track days due to its low-slung exhausts limiting ground clearance, it offers an exhilarating experience on winding roads.
Ducati ST 4, 2000 year, dashboard
Both the ST4 and ST4S are equipped with the same high-performance Brembo brakes found on Ducati's superbikes, providing excellent stopping power. With braided brake lines as standard, the braking performance is robust, though some riders might find the feel lacking. An optional ABS was introduced for the 2003 ST4S, but the standard ST4 did not offer this feature.
Ducati ST3 & ST3s (2004-2007)
Introduced in 2004, the Ducati ST3 built upon the successful foundation of the ST2 and ST4 models, adding its own distinctive flair. It was powered by a unique three-valve engine configuration that utilized two intake valves and a single exhaust valve, producing a commendable 107 bhp and 98 Nm of torque. This innovative head design combined the low-end torque of the two-valve ST2 with the sporty top-end performance of the four-valve ST4, resulting in a versatile power delivery.
Ducati ST 3, 2006 year, right view
Riding the ST3, you immediately experience the charm of a relaxed V-twin, perfectly suited for sport touring. While there may be some initial judder at low RPMs, the engine quickly comes to life, thriving on the power as you navigate through corners. Although it may not be the fastest sport tourer on the market — Ducati intentionally geared it for enhanced acceleration — it embodies the spirit of Bologna with minimal drawbacks. The chassis also impresses with its stability and handling.
Ducati ST 3S, 2005 year, front view
The ST3 is built on the chassis of the ST2 but features several thoughtful refinements. It incorporates the digital dashboard from the Multistrada, and the handlebars can be easily adjusted up or down by 20 mm with just two bolts. Both brake and clutch levers are span-adjustable, the seat has been upgraded to a thicker, softer foam design, and the fairing is wider and taller for improved aerodynamics. Additionally, the headlight position can be electronically adjusted, making the ST3 essentially a more refined version of the ST2. Opting for the S model further enhances the experience with upgraded suspension and the inclusion of ABS.
Ducati ST 3S, 2007 year, dashboard
Although the ST3 was only in production for a brief four years, it saw updates during its run and even gained a sportier variant. In 2005, the engine received a boost of 5 bhp and 5.3 Nm of torque, along with the introduction of a wet clutch to reduce noise. The following year, the ST3 S was added to the lineup, featuring an Öhlins rear shock, TiN-coated slider forks, and ABS. Unfortunately, this enhanced model was short-lived, being discontinued alongside the standard ST3 at the end of 2007.
Ducati's decision to phase out the ST3 was not a reflection of the motorcycle's capabilities but rather a response to shifting market dynamics. The rise of adventure bikes had begun to redefine the sport touring segment, with the Multistrada stepping in to fill that role, ultimately rendering the ST3 obsolete.