What Was So Special About The Ducati Paso?

[Hugh Janus]

When unveiled in 1986, the Ducati Paso 750 represented a high point in motorcycle design with its sleek, functional, fully enclosed bodywork. There was nothing quite like it. (Bruno dePrato /)

In the mid-1980s, the Castiglioni brothers, Gianfranco and Claudio, owned the Cagiva Group and had established excellent ties with the leaders of the major Italian political parties. They liberally used their connections to financially strengthen the group after proving rather successful both in the motorcycle market and on racetracks. These same friends granted the Cagiva Group full control of Ducati at no cost. Not a bad gift.

At the time, Ducati was controlled by a government-owned financial group, and the top managers were so inept that heavy financial losses piled up year after year. Giving it to the Cagiva Group at least cut the hemorrhagic flow. Almost in perfect coincidence with the acquisition of Ducati, Claudio had made a generous offer to Massimo Tamburini, rescuing him from the backstabbing that Massimo had received from his former Bimota partner, Giuseppe Morri. Claudio and Massimo teamed up perfectly, and Claudio entrusted Maestro Massimo Tamburini with the design and development of the new Cagiva and Ducati models.

Ducati was limping badly with its line of models, and Claudio first discussed with Massimo the creation of a model that would radically refresh the company’s image—starting with a breathtaking design, the Massimo Tamburini way. It would be called Paso, for the Aermacchi/Harley-Davidson champion Renzo Pasolini, who died in a terrible crash that also killed Jarno Saarinen on the first lap of the 1973 Italian 350 Grand Prix at Monza.

Tamburini’s mission was a big challenge because the new model had to retain the essence of a real Ducati, with levels of dynamic qualities, styling finesse, comfort, and practicality never achieved before at Borgo Panigale. Tamburini wanted the new model fully wrapped in a sleek fairing that should also grant high-speed comfort.

Perfectly balanced, the Ducati Paso was a great ride, both on the road and at the racetrack. (Bruno dePrato /)

The 750cc OHC Pantah V-twin that would power it was a radical evolution over the previous generation of bevel-driven OHC Ducatis. Dr. Fabio Taglioni had replaced the traditional interference-fit built-up crank assembly turning on roller bearings with a much more reliable solid crankshaft with cap-type connecting rods turning on plain bearings. But still he selected a hybrid solution at the main ends, not plain bearings but the same MRC high-performance angular contact ball bearings that I had selected for the glorious 750/900SS in my days working at Ducati with the great Doctor T. That he still selected them for the Pantah engine I took as an appreciation of a job well done back then.

The sleek, fully faired design Tamburini chose gave him a free hand on frame design, allowing him to make it easier to fabricate (its square tubes welded more easily) and faster to build a bike around on the assembly line. A bolt-in lower cradle gave easy access to the engine for servicing, rather than requiring engine removal as did other Ducatis of the day.

The solid and functional frame structure was nothing compared to the radical revolution Tamburini made in frame geometry. Tamburini never loved any of the previous Ducati chassis for their rear-biased weight distribution and heavy steering geometry. He progressively refined every minor geometric factor of his project to the point that the Paso still is the best-balanced Ducati chassis ever, even today.

Tamburini conceived a square steel tubing frame structure to simplify the production process, and accurately calculated steering geometry and weight-distribution bias. (Bruno dePrato /)

To obtain this precious result, he took advantage of the latest innovations, among them radial tires. Michelin and Pirelli had both developed low-profile 16-inch radials. The 130/60-16 front radial was 22 inches in diameter, a cool 1.58 inches less than today’s standard 120/70-17, and much more compact when compared to the 18-inch tires of the original Pantah.

Keeping the Pantah chassis as a reference, Massimo pulled the steering rake down from 31 to 25 degrees and 95-millimeter trail, but above all, he fully exploited the advantage offered by the much smaller diameter of the new front radial, and retracted the front wheel by more than 2 inches nearer to the center of gravity while adding 2.5 inches to the swingarm, a total geometrical revolution that generated a perfectly balanced chassis spanning a still pleasantly compact 57-inch wheelbase.

One of the Paso’s engine changes was that the head of the vertical rear cylinder was turned 180 degrees to adopt a more rational central induction system. Doing this got rid of the additional cables and unequal throttle response from the traditional Dell’Orto PHF-PHM carbs. In their place was a Weber 44 DCNF automotive-type twin-choke carburetor. The Weber not only returned smoother and had more precise throttle response, but it also improved the torque delivery, moving the 65 hp power peak (net, rear wheel) down from 8,800 to 7,900 rpm. The Weber’s drawback came due to the fully enclosed fairing: In slow traffic, the fuel in the bowl would overheat, and the engine would lose tractability and finally die because there simply wasn’t enough cooling airflow.

The Paso featured a modern and elegant instrumentation cluster. Clip-ons placed atop the upper triple clamp induced a streamlined and sporty but very comfortable riding position. (Bruno dePrato /)

The problem remained even when the old faithful air-cooled 750cc SOHC was replaced by the liquid-cooled 904cc SOHC unit based on the 851 eight-valve Desmo crankcase, complete with the new six-speed gearbox. Named the Paso 906, it represented a sound evolution of the original, since the chassis was more than capable of dealing with the 74 hp peak power at 8,000 rpm and stronger torque of the larger unit. The Paso 906 was much more versatile than the 750, and fast, strong, and handling well, it was a great pleasure to ride anywhere. Top speed easily exceeded 135 mph, finally delivering what the sleek lines of the fairing promised.

When it came time to adopt a new, fuel-injected version of the 904cc unit, Ducati decided to homologate a new chassis and switch to 17-inch wheels, which were then coming into fashion. It was a bad idea, hastily put together and completely overlooking the fact that the wheels and tire sizes were a determinant factor in chassis balance. Using a 120/70-17 front and 170/60-17 rear completely trashed the original dynamic quality of the Paso project. The Paso 907 i.e. was forced to grow taller, not only because of the larger diameter of the wheels and tires at both ends, but also because the front wheel demanded a much taller fork to push the larger front wheel forward in order to clear the front cylinder head. Wheelbase grew by nearly 1.6 inches, and the Paso lost its light, precise steering, and became heavily understeering like other Ducatis of the time.

The only positive brought by the Paso 907 i.e. was its fuel injection, which added a little power (now 78 hp at 8,500 rpm) and completely eliminated carburetion problems. Still, it was the sad swan song of a great project while it should have been the cornerstone on which the Ducati technical team could have built a new competence in motorcycling dynamics. But by then, ­Tamburini was actively working on his perfect Ducati 916 jewel. ­Godspeed Massimo. Always.

Source

[Tym]

Looks like a Pacific Coast Hit a late 80's Ninja up on a one night stand without protection.

[boboneleg]

There is absolutely nothing good about them, you can't give them away.  I sold a front wheel with a good tyre on it (they're 16'' jobbies) on auction and got 99p for it

[Catteeclan]

Bloody ugly.