The convictions of a legendary engineer are vindicated in the evolution of a desmo L-Twin- the Ducati 750 F1
Dr. Taglioni’s Last Stand
For 30 years from 1955, the words Taglioni and Ducati Meccanica were inseparable. An engineering graduate of Bologna University, Fabio Taglioni first joined FB Mondial with a brief stop at Ceccato before moving to Ducati in 1954. Relatively new in the motorcycle business, Ducati was seeking to establish its name in the accepted Italian way: by going racing. In 1953-4 Laverda was the team to beat in the 75cc and 100cc classes of the Milano-Taranto and Giro d’Italia races, so Taglioni designed a new 98cc engine with bevel shaft drive to a single overhead camshaft. Ducati entered a team in the 1955 nine-day Giro, and won the 100cc class outright at an average speed of 98.9 kmh. The bike was the Gran Sport, also known as “Marianna.” A legend was born.
Next came Taglioni’s signature development: a 125cc grand prix race bike using an engine with three camshafts: one each to open the intake and exhaust valves; the third to close them. The system, known as desmodromic, had been used successfully by just one other engine builder, Mercedes, in its 1954 sports racing cars. Taglioni’s desmo valve gear allowed the little Ducati racer to rev to 15,000 rpm.
Ducati’s core production bikes for the next 12 years were the spring valve SOHC “narrow case” singles of 125, 175, 200, 250 and 350cc. It wasn’t until 1968 that desmo engines went into production in the “wide case” 250, 350 and 450 singles. But by the early 1970s, singles were out of fashion: bigger bikes were needed to meet the demands of the US market. By the simple expedient of mounting two OHC singles of 375cc at 90 degrees to each other on a common crankshaft, Taglioni created the classic 750 GT/Sport L-Twin engine. With desmo heads, this begat the 750SS race bike of 1972 that cleaned up in the Imola 200 mile race with Paul Smart and Bruno Spaggiari riding.
The legend embellished!
But legends don’t pay bills. Ducati’s big twins were premium priced and expensive to manufacture, mainly because of the time required to set up the bevel drives and valve adjustment. (The joke went that Ducati was actually a shim manufacturer and built motorcycles as a sideline.) Looking to find a mid-size bike that would complement its range, Ducati introduced 350 and 500cc parallel Twins. Taglioni refused to work on them, as his own proposal for a 500cc L-Twin had been vetoed by Ducati’s then government-backed owners. The parallel Twins failed to sell in spite of a quality specification and (perhaps because of) radical Giugiaro styling.
With the bevel-drive bikes too expensive for volume production, and the parallel Twins tanking in the marketplace, Ducati management turned once again to Taglioni. The story goes that Taglioni smiled, opened the drawer of his desk, and produced a full set of engineering drawings for a 500cc two-valve desmo L-Twin with belt driven cams. It was launched in 1979 as the Pantah.
True to form, it wasn’t long before Ducati went racing with their new bike. Stretched to 600cc as the TT2, it took Tony Rutter to four consecutive Formula Two world championships. Next came the 750cc TT1 designed to compete in Formula One and World Endurance racing. Among its successes were Virginio Ferrari’s Italian Formula One championship in 1985, and wins at most of the famous endurance venues, including Mugello, Montjuich Park, Laguna Seca, and Le Mans. Ducati was back at the top after a decade in the wilderness.
The legend revived!
Financing these efforts was an influx of cash from the sale of engines to Cagiva, a motorcycle builder based in Varese near the Swiss border. Cagiva planned to enter the fast-growing market for large motorcycles, but lacked its own engine, so began sourcing Pantah-based engines from Ducati in 1983. (With Ducati producing around 3,000 motorcycles a year, Cagiva’s first two orders for 6,000 and 10,000 engines was significant!) The Allazzura street bike and dualsport Elefant used a 650cc version of the Pantah engine but with the rear cylinder head reversed, so the exhaust exited out the back.
Meanwhile, Ducati had its own plans for a new streetbike. The 1986 750F1 looked exactly what it was: a street version of the TT1 racer. And while the first generation (sometimes called the F1A) was down on power, the 1987 version put at least some of the grunt back, with larger valves, 36mm Dell’Orto carbs, more aggressive camshafts, 10:1 compression, and a 2-into-1 Conti exhaust for a claimed 75 hp. The engine went into a modified version of the Verlicchi-made TT1 trellis frame with Marzocchi front fork and monoshock rear suspension. Brakes were floating disc Brembos slowing 16-inch Oscam alloy wheels. Bodywork followed the TT1 style, though the “monoposto” seat cowl was enlarged to carry the battery, which somewhat spoiled its sleek lines.
To celebrate their racing success with the TT1, Ducati released limited edition race-replica F1s as the Santa Monica, Montjuich, and Laguna Seca. Then in 1985, Cagiva bought its engine supplier and installed Massimo Bordi as technical director, meaning the F1 and its variants were effectively the last “pure” Taglioni Ducatis.
THE PICTURED EXAMPLE IS FROM THE second 1986-7 production run, often called the “F1B,” but has been modified to bring it closer to Montjuich specification. The engine breathes through larger 40mm Dell’Ortos, though the camshafts and exhaust are stock. A Verlicchi aluminum swingarm replaces the Ducati tubular steel one, and the bike runs on composite wheels using Marvic magnesium hubs and spokes mounted on 16-inch Akront aluminum rims. Like most race replicas (Honda’s RC30 comes to mind), the F1 is surprisingly small and compact: taller riders need not apply. And the styling is uncompromisingly 1980s with its square headlight and seat cowl.
As late fall sunshine softens the vibrant tricolore colour scheme, Brian spins the F1’s engine and after a few coughs from the exhaust and a chuff or two from the open intakes, it comes to life. More modern Ducatis produce a mellow, booming exhaust note, but not the F1, its hard-edged, raucous bark is closer to the crackle of an open pipe-racer. And after all, that’s pretty much what it is.
– Robert Smith, March 2012 (issue #279)