Z-stripe: 1972 Ducati 750 Sport

The Japanese manufacturers were upping the ante in the horsepower stakes, but it wasn’t until the early 1980s that they sold road versions of race winners, such as the Suzuki GS1000S, styled after Wes Cooley’s racer, and the Kawasaki Z1000R, often called the ELR or Eddie Lawson Replica. The closest Japan came to producing anything like Ducati’s original 127mph 750 Sport was the Suzuki GSX-R750 of 1985.

Humble beginnings — and a race win

As the Seventies dawned, Ducati needed bigger machines to replace its long-running singles, but for several crucial years factory engineers had been distracted by a range of dead-end prototypes. These included a 500cc Grand Prix V-twin and an outsourced Ricardo water-cooled 350cc inline triple with fuel injection, as well as the stillborn Apollo V4 police motorcycle of the mid-1960s.

What Ducati needed was a strong, relatively uncomplicated big twin cylinder, capable of both road and race duties. The factory head honchos turned to their go-to designer, Fabio Taglioni, who came up with a winner on both fronts. Taglioni used the cylinders and modified valve gear of Ducati’s long-running single overhead cam singles in a 90-degree “L-twin” configuration that had the front cylinder almost parallel to the ground. Remarkably, it was just a few months between prototype and production, yet despite being a rushed job the 750 GT was a great sales success.

Of course, with Taglioni involved, a race version soon followed, which achieved instant success with the Paul Smart-Bruno Spaggiari one-two finish at the 1972 Imola 200. Their race bikes were close cousins to the 750 GT, except for having desmodromic cylinder heads instead of the GT’s standard overhead camshaft with coil springs.

These desmo racers powered on into the Seventies, eventually being enlarged to 860cc for events such as Spain’s Montjuich 24-hour race. However, in typical convoluted Ducati management decisionmaking, it took a full two years for the Super Sport “desmo” 750 to be released.

In the meantime, Ducati released a non-desmo 750 Sport in 1972 in limited numbers and the full-scale production version went on sale in 1973. Some Ducati historians believe the valvespring Sport was a wasteful development phase and the factory should have leapfrogged into the desmo Super Sport 750, the direct descendant of Smart’s Imola-winner. However, the marketing focus of motorcycle manufacturers at that time was on big-bore, interstate mile-munchers, not race replicas.

So what significance does the 750 Sport have now? Criticized at the time for its overly long, lean look and too-bright orange-yellow paint, but praised for its light weight and road performance, it’s now a much sought-after classic. And the early versions, nicknamed the Z-stripe because of their unique tank decals, are even more desirable.

Man and machine

Achim Gier is a Belgium-based Ducati collector whose passion for the brand began in 1983, with the acquisition of a 10-year-old Ducati 750 GT. Three decades on, he now has a comprehensive collection of bevel twins dating from 1971 to 1985, from 750 to Mille. “Of course, hunting down the rare models became a passion and I always wanted to own one of the first 750 Sport Ducatis, the Z-stripe yellow version, but it had to be an original one,” Achim says. Lost in the maze of replicas on the worldwide market, it took more than 15 years to locate an original one.

Achim explains: “Unfortunately, there are too many replicas on the market. The frame of the Z-stripe Sport has the large rear section of the GT, so a GT frame can easily be modified into a Sport. The fact that the Sport shares the number sequence and homologation (DM750S) with the GT (which also has 750S stamped on the headstock) also makes it difficult to differentiate.”

Apart from some details only relevant to the Sport, the number sequence is the key. “Any number outside of the 751000 to 751500 range will not belong to a real 1972 Sport,” Achim says. No one knows exactly how many Sports with the GT rear frame were built during 1972, but Achim believes most of them stayed in Europe. “The Belgian importer did not receive any,” he says. “Most of them stayed in Italy, and a few went to Germany, France and some other countries.”

Patience paid off for Achim, who acquired his Z-stripe Sport from a fellow collector, who had found the bike in Germany. “I swapped it against a very rare sandcast 750 GT,” he says. After acquiring the bike, Achim started the process of getting his rare Ducati “as perfect as I wanted it.”

Restoration

Inevitably, Achim’s 750 Sport had had some parts changed over its lifetime, including for example the front Borrani rim. “It was very typical for Ducati to modify parts over the years, but not to change the part numbers,” he explains. “So, if in 1976 the front rim needed replacing, you could order it at the local Ducati dealer, but you would get the newer version of the later Sport, which obviously fits very well, but is not original from a collector’s point of view. Given the rarity of the bike and my aspiration for perfection, I started to collect all the new-old-stock parts I could find for it and dismantled the bike.” The first thing he did was completely rebuild the engine, which was not a difficult process. “Original Mondial pistons are the main difference to the lower compression GT, and parts were available in my stock, including the newly zinc-plated original screws,” Achim says.

He then turned to rebuilding the wheels, and Achim soon realized how maintaining his attention to detail would make this possibly a unique restoration. “Although the Borrani front rim had the correct reference of 4403, the spacing of the stamps on the rim showed it was a 1974 version,” he says. “An original 1972 rim was found and laced to the original, two-piece hub.” (Later versions had a one-piece front hub.)

Then there was the matter of the optional front fairing offered only for the 750 Sport. It was a strange affair that allowed the fork-mounted headlight and instruments to rotate inside a large front opening. “Luckily, I had bought an original factory fairing many years ago, but the original hardware to fix it to the frame was missing,” Achim says. “I sourced the chrome brackets in Canada, found the screen that goes in front of the headlight in the U.S. and got some last-minute pieces from Bevel Rubber in Australia, whom I highly recommend for their service and quality.”

One of the biggest pieces in the jigsaw puzzle was the paint. In typical Ducati fashion, batches of its models reflect the paint available at the time, so there is no definitive shade of the distinctive orange-yellow you see on a 750 Sport. “I got my painter to match the color from original new parts that were not yet affected by UV radiation, which tends to lighten the orange color after just a few years,” Achim says.

After painting came the fiddly job of fitting the original waterslide decals. “This was a very difficult task,” Achim says.”The large decal on the tank nearly drove me mad. It is in one piece and the tank is curved in three dimensions.”

Results

Achim eloquently describes how the final assembly was the most rewarding part of his long journey of restoration and model discovery. “It really gives you the impression you have created something special,” he says, adding, “although, of course, you are just repeating exactly what the factory did some 40 years ago!”

He says that when people view his 750 Sport, they are surprised at its level of originality. But he isn’t. “I paid attention to the smallest details,” Achim says, “like the markings on every bolt and the correct size of every washer and nut. The fuel lines are new-old-stock items with the correct white inscriptions, as is the black breather tube. The ignition wires are original old stock of the correct orange color with original KLG spark plugs… I could probably go on forever detailing the special features of this bike. Without a stock of original parts and a very good worldwide network of collectors and specialists, it is impossible to undertake such a restoration.” Thanks to Achim, there’s at least one perfect and correct early Ducati 750 Sport amongst the horde of pretenders. MC

750 Sport prototype replica

Ducati built three 750 Sport prototypes, two running and one a mock-up. The intention was to gauge public reaction, and they certainly made a statement. White frames and black tanks, along with special curved mufflers, never made it into production, but the basic design captured the imagination of a niche of road riders seeking the race track experience at their doorstep.

Some 15 years ago, Ducati enthusiast Rob Labordus became intrigued by this little chapter in Ducati’s history. “I believe that the three prototypes were lost after being sent back to Italy; dismantled and used for parts,” he says. That inspired him to create a replica of one of the three prototypes, based on black-and-white photos.

“My friend Robert Buijs had an incomplete but dismantled round-case GT,” he says. “In those days round-case Ducatis weren’t expensive bikes — perhaps today the decision would have been different.” The pair pored over the few grainy photos they had with a magnifying glass and many parts were rebuilt and others adapted — notably the exhaust pipes. “There was a lot of measuring and scaling up from the photographs,” Rob says.

They struck a major hurdle when it came to reproducing the paint scheme. “As we based the whole project on a few black-and-white snaps, we weren’t even 100 percent sure of the color,” he says. “There are many two-tone colors that appear black-and-white on old photos. Eventually, we found a color print and that proved that our decision was correct.”

Every once in a while a so-called prototype turns up, but Rob is wary. “To date, each one has proved to be too early, in the wrong frame, iffy background, etc.,” he says. “I still claim that mine is the best attempt at recreating one of the original prototypes.”