Ducati 750 Sport "Z Stripe"

Photos for WhiteOut Studios

Now I will openly admit I am not a bike person, however this 750 Sport is a beautiful bike! The sort of bike which makes you think "hmmm, maybe I should get into bikes!?".

Rather than trying to fake my way through a write up. Here is a very well informed extract from https://www.ducaticlassics.com/motorcycles/750-gt-and-sport

In the early seventies, Fabio Taglioni was at the edge of technical possibilities with the single cylinder engine. Ducati was in desperate need for something completely new in the race for bigger, faster and more, which had just begun after Honda's daring project with the successful CB750. One was not taken seriously anymore with a bike under 650cc...

Taglioni had developed a technical masterpiece in 1964 known as the 1200 Apollo, developed for the American Police. Regretfully it didn't come any further than a prototype stadium, as this gigantic motorcycle was decades ahead of its time and too powerful for the available tyres. Ducati managers Fredmano Spairani and Arnoldo Milvio gave orders to Taglioni to design a new revolutionary engine concept that would lead Ducati into a new era. The result was both simple and brilliant.

Taglioni combined two bevel drive single cylinders on a common crankshaft that led to the first (now so characteristic) Ducati trademark L-twin. When in spring 1970 the drawing tables were cleared for other designs and ideas, the first prototype was tested in July. And with success, because only sixty days later the first Ducati 750 GT struck the Italian press like thunder. Though sporty looking, the driving characteristics were more those of a touring model.

Because of the L-twin concept this Ducati was "built around", it became a model with a rather long wheelbase (1530 mm). The engine was equipped with 28 bearings, no less than 9 of those just to lead the bevel gears, so the idea might have been simple, the construction wasn't! The 750 GT was the first Ducati with 12 Volt electric circuit. The model was surprisingly light with 185 kg. The road holding was quite excellent and proved a good starting-point for developing a more sporting machine, the later 750 Sport.

The first Ducati 750 GT’s of 1971 and 1972 were fitted with Amal Concentric carburettors and a ‘leading axle’ Marzocchi front fork with polished legs and Lockheed twin piston brake callipers on a single disc, later replaced by Scarab brakes in 1972. Early models also featured Smiths instruments until 1973 when they were replaced by Veglia instruments.

1972 also saw the introduction of the first 750 Sport, still using the basic (wide rear sub-frame) 750 GT frame. The leading axle Marzocchi front fork was similar but with black painted fork legs and the bike was fitted with a single Lockheed brake system. The 750 Sport was fitted with clip-on handlebars and rear-set foot pegs. This early model had a very distinctive black Z-shape stripe on the newly designed fiberglass yellow fuel tank and later became known as the Z-stripe version of the 750 Sport.

The 1973 Ducati 750 GT was fitted with Dell’Orto PHF30A carburettors and had a steel fuel tank and painted steel mudguards, instead of stainless steel as used before. Further changes occurred in 1974 when the engine design got a mild update and a centre axle Ceriani fork and a Brembo brake disc was fitted.

The 750 Sport was also updated in 1973 with a narrower rear sub frame with ‘outboard’ mounted rear shock absorbers. The fiberglass fuel tank was narrower to fit the new frame and was finished with a black stripe in the centre and two smaller ones on the side with the Ducati logo. Side covers and seat were now only yellow. Scarab brakes were now fitted. As with the 750 GT, the 1974 750 Sport received a new steel fuel tank in 1974 along with either a Ceriani or Marzocchi centre axle front fork and either Brembo or Scarab braking system.

Taglioni’s brilliant engine design had a combination of bevel gears, used to drive the two camshafts. It is extremely time consuming and takes a high level of skill to assemble these with the correct backlash on all gears. It took more than a full day for a skilled worker to manufacture one single engine. It became clear that an engine redesign was necessary to cope with the financial department and government regulations.

Production of the 750 ‘round-case’ models ceased in 1974 and with it came an end to one of the best motorcycles ever produced in Borgo Panigale. It marked the end of the ‘round case’ 750-era. For many enthusiasts, the handling, the drive, the comfort and the looks the Ducati 750 GT and 750 Sport offer is unparalleled with any other bike in history.

ENGINE

The 750 GT and Sport ‘round case’ engine has vertically split aluminium crankcases, a 90-degree L-twin layout with the vertical cylinder inclined at 15 degrees upwards. The five-speed gearbox is incorporated in the engine crankcase and all 750 GT’s and Sports have a right-side gearshift. The valves are actuated by single overhead camshafts driven by a set of bevel gears and uses valve springs for closing (non-desmo).

Early 750 GT’s were fitted with Amal concentric carburettors, while later models are fitted with Dell’Orto PHM30A carburettors. All 750 Sports are fitted with Dell’Orto PHF32A carburettors. Engine covers were painted black on 1972 and 1973 Sports but polished on all GT’s and 1974 Sports. The ’74 engine has updated camshafts.

FRAME

The 750 GT frame was a completely new development, although it incorporated some of the basics of the earlier ‘wide case’ single frame. With its tubular steel frame, that uses the engine as a stressed member, the 750 GT soon earned a reputation to be one of the best handling bikes available. Early models were fitted with a leading axle Marzocchi front fork with polished legs and a Lockheed disc brake to be replaced in 1973 by the same front fork with black painted legs and a Scarab disc brake. The 1974 750 GT is fitted with a centre axle Ceriani front fork and a Brembo disc brake. The 1972 Z-stripe 750 Sport frame was largely the same as that of the 750 GT.

The 1973 and ‘74 750 Sport models had a narrower rear sub frame and had the rear shocks mounted outside the frame rather than under it. 1972 and ‘73 models were fitted with a leading axle Marzocchi front fork with black painted fork legs. Only a few early models featured a Lockheed brake system, very soon to be replaced by a Scarab brake system. All 1974 750 Sports have a centre axle front fork, mostly Ceriani although some were also fitted with Marzocchi (still with centre axle). Ceriani versions were fitted with a Brembo brake system, Marzocchi version with Scarab.