Ducati 502 Single: Better By Half?

Ducati 502 Single: Better by half?

ROUNDUP

CALL IT RETROGRADE. CALL IT oddball, but for a small, vocal minority, riding enjoyment goes up as the number of cylinders goes down. So if a Four is good, a Twin is better, and, it logically follows, a Single is better still.

That's the sort of thinking at least partly responsible for the current commercial success of Ducati’s V-Twin lineup, and it's led to the inevitable—the Ducati 502, a Single based on half the 851 V-Twin.

The 502 isn't a complete production motorcycle just yet. Rather, it's a prototype nearing the end of its preliminary development stage.

With its horizontal cylinder, the engine looks like nothing so much as a modern version of the old Aermacchi lay-down Single, but there are important differences.

First, the engine is liquid-cooled. Second, its cams are belt-driven. Third, it uses a four-valve head. Finally, its one-and-only piston is counterbalanced by an articulated connecting rod that actuates a moving weight mounted roughly where the second, vertical, cylinder would be on a normal Ducati Twin. The system may sound w^eird, but it works, effectively damping vibration even at the five-figure rpm this engine will turn.

In 487cc form, the engine has successfully concluded durability testing on the Ducati dyno, where it developed a claimed 62.5 horsepower. Ducati chief designer Massimo Bordi expects the 502 to deliver 52-55 horsepower at 9000 rpm in street tune. But when development is complete, he says, 70 horsepower ought to be possible fora race-tuned 502. A six-speed gearbox and dry clutch will be used, though Bordi says he's planning to fit wet clutches to all Ducati streetbikes in the future. A 502 test mule was scheduled for the factory's test track in September, and the results of those test sessions will evolve the final chassis common to the several versions of the bike planned. This is certain to be based on the Ducati tubular-steel spaceframe, with an upside-down fork and cantilever single-shock rear suspension. A lone, 12.6-inch front disc pinched by a four-piston caliper, and a 9.4-inch rear rotor will be fitted on all 502 Singles except a planned race version, which wall have a smaller rear brake. The bike’s weight is expected to be under 242 pounds in race form, and around 290 pounds with street equipment.

Those eager for this sort of motorcycle wall have to wait until at least late 1992 for its launch. And even then, there's no guarantee it will be exported to the U.S. American riders can hope, though; early styling exercises suggest a bike any Single enthusiast would kill to own.

—Alan Cathcart