1974 Ducati 750 GT
- Engine: 748cc air-cooled SOHC 4-stroke 90-degee V-twin, 80mm x 74.4mm bore and stroke, 8.5:1 compression ratio, 49.9hp @ 7,114rpm
- Top speed: 122mph (period estimate)
- Carburetion: Twin 30mm Dell’Ortos
- Electrics: 12v, coil and breaker points ignition
- Transmission: 5-speed, right foot shift, chain final drive
- Frame/wheelbase: Dual downtube frame w/engine as a stressed member/60in (1,524mm)
- Suspension: Marzocchi leading axle telescopic forks front, dual Marzocchi shocks rear
- Fuel tank/MPG: 4.5gal (a)/30-35mpg (period test)
- Weight (dry): 407lb (185kg)
- Brakes: 11in (279.4mm) disc front, 7.9in (200mm) SLS drum rear
- Tires: 3.25 x 19in front, 3.50 x 18in rear
- Seat height: 30.5in (775mm)
- Price then/now: $1,995/$15,000-$30,000
Bevel-drive overhead cam 750cc Ducati twins from the 1970s are undeniably special. The allure of the bevel-drive twin has grown to the point where a top of the line round case Super Sport can presently bring in over $190,000 at auction. The GT version, like the one Scott Somers owns, doesn’t have the desmo heads and race pedigree, but it does have a much less aggressive riding position, and 750 GTs can be had for a much more reasonable price. Scott says it is a joy to ride on back roads.
From little to big
Ducati started building motorcycles in the 1940s. In the aftermath of World War II, Italy was in shambles, with many people trying desperately to survive. With the railway system in ruins, inexpensive transportation was a necessity, and large numbers of small factories manufacturing tiny motorcycles and engine-powered bicycles popped up like mushrooms after rain. Ducati, a manufacturer of electronic components pre-World War II, decided to enter the fray with the Cucciolo (“little pup”), a clip on engine for bicycles. The Cucciolo proved popular, and Ducati went on to build small two-wheelers for the Italian market.
A proven way to advertise the product in the 1940s and 1950s in Italy was to win races. Motorcycle races were popular events in postwar Italy, and the intense interest in racing meant that winning a widely advertised race could boost the fortunes of a previously unknown company. Ducati hired Ingegnere (Engineer) Fabio Taglioni to design a race-winning motorcycle. The story is told that he was informed that he would not get paid unless Ducati won the Giro D’Italia, an important race.
One of Taglioni’s first creations for Ducati, the 100cc Gran Sport, took Ducati to the checkered flag and put the company on the Italian map. Sales climbed. Ducati built increasingly larger capacity singles, some of which had desmodromic valve actuation, an idea that Taglioni championed and developed. Desmo valves close via a cam and lever system, not solely by valve springs, enabling a 4-stroke motorcycle to rev high without valve float.
Ducati’s products were soon exported to other countries in Europe and then to the United States, where the peppy and beautiful little Italian machines developed a following. Berliner, the American importer, and other export markets wanted a larger capacity machine to compete with Triumph, Norton, and the Honda 750 Four. After several false starts and a change in management, Taglioni was given the go ahead to develop a twin in 1970. Repurposing a lot of the parts from the singles, a 90-degree 750cc twin was being tested towards the end of that year, and went on sale in July 1971.
Despite being a commercial product, the twins were built with little regard for cost. Ducati chronicler Ian Falloon remarks, “The bevel-gear layout was a tribute to Taglioni’s engineering purism, but incredibly time-consuming and expensive to manufacture and assemble.” Like the singles, the new twin used the engine as a stressed member of the frame. The valves were actuated by a single overhead camshaft. Leading axle Marzocchi forks aided handling, and a Lockheed front disc hauled in the beast. The cylinder configuration provided a low center of gravity, and the 90 degree V-twin layout gave excellent primary balance, eliminating much vibration, although it resulted in a long wheelbase. The new Ducati was light, just 409 pounds dry. Its transmission sported five gears at a time when the majority of motorcycles had four. And, of course, being Italian, it was beautifully styled. However, sales were at first marginal, due to the relative high cost of the new machine and its touring-oriented appearance. The GT cost a little less than $2,000, not as much as a Harley Sportster, but more than a Honda 750.
A higher compression and more stylish version, the Sport, appeared in early 1972. The first-ever race on the Imola track in northern Italy (and not that far from the Ducati factory) was in April of that year. Heroic work by Taglioni and his team readied several race bikes. Well known racer Paul Smart came home one day and found his wife had accepted a berth on the factory team for him, on what was then a totally untried and unknown motorcycle. The Ducati team — Smart and factory tester Bruno Spaggiari — faced a battle tested lineup of BSA, MV Agusta (with Agostini on board) Honda, Moto Guzzi, Norton and Triumph. But when the green flag dropped, Smart and Spaggiari blasted past the pack, wove their way past Agostini and coasted to victory, Smart taking the checkered flag. Sales of the V-twin went through the roof.
The first U.S. test reports showed up in the Fall of 1972. It was obvious that the motorcycle magazine fraternity of the early 1970s had deep and genuine enthusiasm for the new twin. They all raved about the big Duck. “Ducati’s new 750 V-twin is as animal as anything you can buy these days,” exclaimed Cycle World. “You know a motorcyclist designed this machine and he got it right,” stated Cycle. Testers were willing to overlook the hard pull on the clutch, tall first gear, long wheelbase, and not quite up to par fiberglass in order to focus on the perfect spacing of gears two through five, the narrow single overhead camshaft engine with a low center of gravity, the superb (for 1972) handling, extra oil capacity, molybdenum steel frame and excellent (for 1972) front disc brake.
On the road, testers liked the wide power band, excellent suspension and predictable stopping ability. “The Ducati feels properly stiff without being rock hard.” They approved of the chain adjusters inside the swingarm tubes, which afforded a precise method of tightening the chain. They also liked the lack of both vibration and oil leaks. “What you get is an incredible smooth large displacement twin” said Cycle.
Cycle ran a Superbike Shootout in 1973. A 750 GT was one of the seven participants. Unfortunately, the testers were not able to formulate a point system for measuring happiness on a twisty road, which was (and is) a GT’s forte. The Ducati came in fourth in the braking test, fifth spot in the lap time test (testers stated that this was due to poor choice of rear tire) and fifth place in both quarter mile acceleration and terminal speed. The magazine also tested horsepower and torque and found the Ducati had 49.91 horses on tap, and 43.22 foot pounds torque. While everyone loved the Ducati’s exhaust note, a decibel test found it was illegally loud. The GT ended up in fifth place. Cycle was apologetic, acknowledging that the Ducati was “cruelly restricted” by the nature of the test.
Ducati built about 4,100 GTs between 1971 and 1974. In the mid-1970s, the company planned to replace the 750 GT with the newly designed 860 GT, but the 860 was not styled with traditional Italian panache, and did not sell well. Instead, a developed version of the 750 Sport, the 900SS, which Ducati had originally planned as a limited production machine, was built in larger quantities and became a best seller. In 1977, Ducati came out with the more civilized Darmah. In the mid-1980s, the expensive bevel drives were replaced with belt drive to the overhead cams. Through economic ups and downs, racing wins and losses, Ducati is still holding forth in Borgo Panigale, Italy, building beautiful, fast motorcycles.
Lots of love
Many people continue to ride the older Ducatis despite the availability of new, state of the art machines. A website, bevelheaven.com, caters to Ducatisti who crave the bella musica of the bevel-drive twins of the 1970s and 1980s. Bevel Heaven occasionally locates Ducati twins for customers, and that is how Scott Somers found his very own bevel-drive Ducati.
At the time, two years ago, Scott was in a quandary. He had just sold a John Player Norton Commando (“too much of an aggressive cafe racer”) and the money was burning a hole in his pocket. He thought back to the days of his youth, when he worked for a Ducati dealer. “I had two different Ducati round cases. They were ‘the ones that got away.’ I sold the first one, but five years later I missed having a Ducati, so I bought a used 1974 Sport. In the mid 1980s, I had a mortgage, kids and a car payment. Someone made me an offer on the Sport that amazed me, so I sold it.” Scott started regretting that decision as soon as the bike left his garage.
Scott decided to see if an affordable bevel-drive 750 could be found. “The Bevel Heaven website was down, so I called Steve Allen, Bevel Heaven’s owner. He said, “If you are really serious, let me get back to you.” Allen located this GT in Canada and put Scott in touch with the owner. It was shipped to the U.S. just before the border got locked down due to Covid. “On a little bit of faith,” Scott waited nervously for his new ride.
Tweaks and fixes
The 1974 GT that was unloaded from the truck was close to, but not quite as advertised. The engine had the factory seal, meaning that the cases had never been split. It had the original paint, and, amazingly, the original exhaust with no rust or dents. Scott knew it hadn’t been ridden for eight years and needed new tires, a battery and a careful check of the engine. What he didn’t know about was the oil leak from the bottom of the front tower. The cast-aluminum flange had cracked, due to overtorquing and incorrect shims. The wizards at Norman Racing in Berkeley, California, rewelded and machined the flange (new ones are unobtainable) while Scott located a correct gasket in Europe. The assembly is now set up with correct shims, torqued to correct specs, and the oil stays in the cases where it belongs. A friend with experience with race engines, Scott Dunlavey, figured out the problem, and the two Scotts reassembled the engine, putting all the little shims (bevel-drive Ducatis have shims all over the place) in the right spots.
Scott (the owner) replaced all the hoses on general principles and bled the brakes. The old oil was replaced with Kendall GT1 Competition oil. He also removed the mirrors the bike came with and installed period correct Napoleon mirrors. While going through the bike, he discovered that it was originally a U.S.-spec bike, delivered by the factory to legendary dealer Ed Brooks in central California. A plastic bag and an owner’s manual stamped with the Brooks logo came with the bike.
By February 2021, Scott’s GT was on the road. “It definitely makes music. When it’s running right, it makes everything I had to go through all better.” At this point Scott has put 450 miles on the bike and plans to keep riding it on a regular basis. In order to do that, the maintenance has to be kept up. Scott checks the carb synch on a regular basis. “I can feel when they slip out of adjustment.” Once a year, he checks off a list of maintenance items and changes the oil.
The starting ritual is not very involved: turn the key on, put the bike in neutral, kick through until it is on the compression stroke, and kick hard. “It will start on either the first or the third kick, but not the second one for some reason.” The GT will warm up in a couple of minutes and settle into a loping idle. “Even through the first gear is tall, you don’t have to slip the clutch to get going. The clutch is heavy by today’s standards but only a little bit more than my other bike, a Norton Commando, so I have no problem with it even in traffic. The GT has a long wheelbase, but a very low center of gravity. I find it very stable in all situations, especially in traffic. The steering is slow but easy to adapt to.” One plus of having a touring bike rather than a sport bike is the superior passenger accommodations. Scott’s wife Susie enjoys riding pillion on the Ducati. The well balanced engine is smooth, with no vibration in most of the rpm range. Susie also likes the exhaust note, although she says it’s “a little throaty.”
That rpm range is wide. Scott says that the GT will pull in 3rd gear from 1,500rpm, “but doesn’t like it. It’s also not a good idea to do that too often. It puts strain on the crank bearings, which can be a weak spot on the bike.”
“You have to work to go fast on tight mountain roads. It’s an acquired skill. The bike is light and agile. It is very comfortable at modern freeway speeds. It will keep up with traffic with no problem,” Scott says. “A bevel drive Ducati looks and feels and sounds like no other motorcycle. It really is unique. An air-cooled bevel-gear Ducati has one of the iconic sounds, especially with a set of Conti mufflers. There’s a different feel to an older Ducati.”
“A motorcycle to me is just that — a motor in a cycle. I like looking at the engine in my Ducati. Italians have a remarkable flair for design. They are passionate about performance and design. This bike screams Italian.” MC