'The GT’s designer, noted car stylist Giorgetto Giugiaro (creator of the Lotus Esprit, VW Golf, and many others), had combined the new Gran Turismo machine’s striking lines with handlebars that not only made sustained high-speed riding uncomfortable, but
we look back to one of the sweetest-handling street-bikes of the time
THIS SHOULD NOT HAVE been happening. There I was, banking through a gentle right-hand curve with the 860GT's speedometer reading about 130 km/h, when a slight twitch of the handlebars announced the start of a gentle weave. The bike settled down again when I slowed slightly, and it was certainly nothing worrying — but even so! Back in the mid-1970s, when this bike was built, Ducati's reputation for high-speed handling and stability was second to none.
My first thought was that the GT's tendency to get slightly light-headed at speed was due to this particular bike's age and condition. But a look through some old magazine tests revealed that the 860GT was criticised for exactly the same thing when it was new in 1975. Words like “weave” and “wobble” had not been necessary when testing previous Ducatis such as the 450 Desmo single or the 750GT, but were used about the 860 by testers who were even more surprised than I was all these years later.
At least the problem could easily be solved, because it was traced to the high, wide handlebars that helped give this bike a very different look from previous Ducatis. The GT's designer, noted car stylist Giorgetto Giugiaro (creator of the Lotus Esprit, VW Golf, and many others), had combined the new Gran Turismo machine's striking lines with handlebars that not only made sustained high-speed riding uncomfortable, but also created disruptive steering forces that even the
Ducati's basically sound chassis could not completely control.
That did not prevent contemporary testers from giving the 860GT an enthusiastic welcome, and concluding that a redesigned riding position was the only thing it needed to become a superb machine. By no means everyone liked the angular shape, but Ducati's first bigbore sports-tourer was certainly distinctive, as well as being the largest-capacity bike that the firm had ever put into production. And if it didn't match the glamour or sheer speed of the 900SS that followed it into showrooms in the same year, the GT promised plenty of performance along with more practicality and a lower price.
Its air-cooled, 864-cc V-twin motor was essentially a pair of Ducati's 450 single-cylinder motors on a common crankcase. Cylinder angle was 90 degrees, drive to the single overhead camshafts was by bevel gear, and the GT used conventional valve operation rather than the desmodromic system that would be employed for the SS. Ducati revealed that peak power was produced at 6,900 rpm. No figure was given for the output, but the tuned SS produced a claimed 80 PS, so the GT's figure would have been a little less than 70 PS at the crankshaft.
This softly-tuned motor might not have had the desmo valvegear or high-revving horsepower of the SS, but by mid-'70s standards it was still an impressive powerplant. “As anyone who has done so will tell you, the only thing that beats riding a good 450 MkIII single is riding two,” one tester gushed. “The 860 engine has all the single's virtues of endless torque, mechanical refinement and sheer force of character — squared. The 860 motor is undoubtedly one of the world's finest motorcycle engines.”
Beneath its bold blue bodywork the Ducati's chassis was a typical Bolognese blend of tubular steel frame and firm, Italian-made forks and shocks, supplied by Ceriani and Marzocchi respectively. This 1975-model bike was in good condition, especially considering Ducati's reputation for poor finish. It was standard apart from its instruments and seat, which were from the following year's 860GTS.
The later seat was slightly thinner, to reduce the GT's excessive seat height slightly. That didn't keep the bike from feeling tall when I climbed aboard, quickly becoming conscious not just of the pulledback bars but also the forward-set foot-rests. The right foot-peg made itself felt almost immediately, because as the GT had no electric starter (one had been available as an optional extra) I had to kickstart it — and the foot-rest was perfectly placed to come into contact with a kick-starting leg's shin .... Ouch!
Such inconveniences were forgiven when the big V-twin lump burst into life with a fairly restrained V-twin rumble, and proceeded to show just why it was such a good device for a sports-tourer. Thanks partly to its low state of tune the engine was superbly responsive through the mid-range. This bike's pair of conventionally filtered 32-mm
Ducati’s first 864-cc V-twin had a few flaws, but the 860GT deserves a place in the Bologna hall of fame nevertheless
Dell'Ortos looked ordinary compared to the gaping 40-mm units of the SS, but when tugged open they sent the bike surging forward with plenty of urgency.
Like many later big Ducatis the V-twin was snatchy below about 3,000 rpm, but smoothed out from then on. Vibration wasn't a problem even up near the 7,000-rpm red-line, although the big lump felt best between 3,500 rpm and about six grand, and its mid-range torque meant there was little incentive to use all the revs. Generally, it was much better to change up early through the five-speed box, which shifted smoothly enough to make me forgive the neutral light's traditional hopelessness.
Given the slightest opportunity the Ducati accelerated pretty rapidly up to an indicated 145 km/h, beginning to feel slightly unsteady by that speed even in a straight line, and would have gone on to a top speed of about 185 km/h. Those high bars meant you'd have to be both brave and strong-necked to hold such speeds for long, though, and even my steady 130 km/h became tiring after a while.
That slight high-speed weave gave Ducati's reputation for unbeatable stability a knock but never threatened to get bad enough to do any damage of a more physical nature. At least the bike regained some points with its handling in slower bends. The GT's rigid chassis and high-quality suspension gave cornering power that few
bikes could match in 1975. Chassis geometry was chosen for stability, and the good thing about the wide bars was that their leverage made for easy steering.
Once into a turn the Ducati sailed round in style, its firm suspension letting the rider know just what was going on. Only the unlikely tyre choice — Chen Shins rather than Pirellis on a classic Ducati? — prevented me from doing the foot-rests more damage in the corners. At least, I didn't have to worry about the front tyre's lack of grip when using the front brake. The single 280-mm Brembo disc lacked bite and gave a very wooden feel at the lever. A second disc was available as an optional extra, and would have been well worth having, along with stickier rubber.
Ducati did at least demonstrate a willingness to listen to criticism, as the following year the 860GTS was launched not just with the GT's optional second front disc and electric starter as standard, but with flatter handlebars too. For European riders the GTS was basically the Gran Turismo machine that the GT should have been all along. Its high-speed stability was impeccable (proving that the original model's problem was due to the bars, as suspected), it was well braked and started effortlessly.
Being a Ducati, of course, it still had a few annoying faults, particularly the corrosion-prone paint finish and awful switchgear that made it all too easy to plunge yourself into darkness when trying to operate the headlight's dip-switch. But with a sportier riding position the bike's performance could be more easily used, and the essential quality of the original GT model's design shone through. Ducati's first 864-cc V-twin had a few flaws, but the 860GT deserves a place in the Bologna hall of fame nevertheless.
Ducati's first 864-cc V-twin impressed testers of that time
Instrumentation was borrowed from the 860GTS
Marzocchi shocks handled rear suspension duty
280-mm single disc reined in the front. Second disc was optional
Wide handlebars made it nervous at high speed