Ducati ST4 - 2005

The ST4s provides an amazing mix of characteristics. Its 4 valve engine, designed for relaxed touring on long journeys even at full load and constant high speed, is complemented by a frame derived directly from the Superbike series. Handling is made even better by fully adjustable suspension and a riding position that guarantees comfort and control for riders and passengers of all heights. When it comes to fast touring and total control, the ST4s knows no rivals.

ABS

The ST4s ABS has exactly the same incredible stability and handling in the bends as the ST4s, but with an even greater safety margin guaranteed by Ducati's own sophisticated ABS system. ABS plus brakes worthy of any racing machine means increased confidence in using the bike's fantastic engine power, and handling to the fullest.

Style

To the eye, the ST4s and ST4s ABS are distinguishable only by the name which highlights the presence of the anti-locking braking system, and of course by the electronic and mechanical components that set the two braking systems apart. Both bikes are modern in styling with the large effective lights first introduced in the ST family on the 2004 models and feature the latest fairing fasteners. The purpose of this innovation is to simplify access to all those parts that are hidden behind the fairing, like the oil filler and battery. The height adjustable handlebars are another fundamental aspect of ST series styling, as is the multifunctional instrument panel that receives and displays its information over the CAN (Controller Area Network), a technology previously used only in the automobile industry and based on a wiring loom of just two wires.

Chassis

The presence of a superbike engine means that the chassis of the ST4s and ST4s ABS simply has to be the best. In fact, the large variations in load to which a touring bike can be subjected makes finding the right setup even more difficult than on a racing motorcycle designed only for track use. The trellis frame, a consolidated reference point in Ducati technology, is therefore assisted by top quality suspension of the type used on far more sports oriented machines.

The front fork, a Showa with TiN coated stanchions normally used only on racing bikes, provides excellent opportunity for personalisation for riders seeking the perfect setup (TiN surface treatment reduces friction and improves fork action). An Ohlins monoshock gives the same adjustments for compression and rebound at the rear, plus a remote adjustment for spring pre-load. The aluminium swing arm is the best solution there is in terms of weight, and responds perfectly to the widely varying stresses that can come from different road surfaces and load conditions. Just like the ST3, the ST4s also features a 245 millimetres rear disk and a pair of 320 semi-floating disks at the front. What sets the two models apart is the distinctive aluminium alloy front disk flange used on the ST4s to reduce rotating mass. On the ST4s ABS this is complemented by a highly developed ABS system that reduces the risk of wheel locking during braking on slippery road surfaces.

ABS

The anti-locking braking system fitted to the ST4s ABS is far more advanced and sophisticated than those found on other motorcycles.The system receives separate data from phonic wheels attached to the front and rear disks. Sensors transmit data from the front and rear phonic wheels to a control unit that processes it separately using special software to compares the average speed of both wheels with the speed of each wheel at any instant in time. If the ratio between these speeds exceeds the safety threshold, the control unit intervenes at the calliper that is applying excessive pressure, and therefore risking wheel lock. Reaction is immediate, with pressure being reduced in the circuit concerned by a set of pressure relief valves. As soon as wheel speed returns within tolerance, the pressure relief valve is closed to restore full pressure. The main benefit of Ducati's ABS system lies in the feel of the braking system which is identical to that of conventional braking systems. Riders simply cannot detect any difference in action between the brake lever, brake pedal and callipers.

And in the unlikely event of a failure in the control unit or any of its sensors, the system carries on working exactly like a conventional braking system, with ultra-short stopping distances guaranteed by the braking power of three generous disks derived directly from the Superbike family.

Engine

To ensure the sort of performance capable of satisfying even the fastest, most demanding touring riders, Ducati has chosen a truly thoroughbred twin, the Desmoquattro, specially prepared for sport touring. With 121 HP at 8750 rpm and 10,5 kgm at 7250 rpm, this engine packs plenty of punch, in addition to smooth and reliable power delivery from the electronic fuel injection system. These characteristics, already appreciated by those lucky enough to ride a 2004 model ST4s, have been further enhanced in the 2005 model by a new oil bath clutch. The new clutch means far quieter running, smoother action and above all a working life that can reach hundreds of thousand of kilometres.

Specification