Fabio Taglioni, engineer Ducati

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Fabio Taglioni, and Ducati motorcycles with him, always remained faithful to a very distinctive philosophy. Even when the whole motorcycle world was going in the direction of bigger-heavier-wider-more-cylinders-more-power, following the economical boom of the 70s, his bikes remained light, thin, simple, efficient. They had one or two cylinders and did not produce an overwhelming power, but they were able to exploit every fraction of their horsepower to the best. This philosophy was often deemed “outdated” and “obsolete” by many observers and, analyzing it in a rational way, we must admit that they were probably right. But take a look at what happened later, and what is still going on now to high performance motorcycles, before you pronounce a judgement.In the ‘50s, Fabio Taglioni designed a peculiar system to bring the valves back to their seats without using springs. It was his graduation thesis at the Faculty of Engineering of the University of Bologna. This system was rather complicated and difficult to set up properly but it promised to solve radically the problem that afflicted all sport and racing engines of the time: valve springs breakage when the engine over-revved. Taglioni eventually solved the problem of setting up the system properly and, fifteen years later, Taglioni’s “desmo” valve actuation was applied to a production engine. Fifteen further years later, the Desmo system was still a trademark and distinctive trait of Ducati motorcycles but by then, everybody agreed that valve springs breaking under stress was not a problem anymore and the Desmo system was just a “mechanical wonder” good only to attract a certain kind of mech-nut customer and to give Ducati that distinctive trait which allowed the brand to carve its niche in a market dominated by bikes that were producing 50% more horsepower per cubic centimetre than the best Ducati.

Meanwhile, four small valves had taken the place of two big ones everywhere, except in Ducati motors. Valve springs had an easier job to accomplish now, they were made of better materials and employing complicated mechanical device to do without springs was like making mechanical watches to do without batteries. But that system survived Taglioni himself and now, every Ducati of the 21st century, up to the motoGP racing bike, has it. In a motoGP bike, designers have little room for useless devices and “brand traits”: either it makes more horspower, or it cannot be there. This means that the grand-son of that original design of fifty years ago by engineer Fabio Taglioni, still has a right to be in a top-performance engine. Can it still be deemed obsolete?

For fifty years Ducati bikes followed the same philosophy, that we can rightfully call the “Taglioni philosophy”: lightness and compactness opposed to the quest for sheer power; mechanical and combustion efficiency; modularity of components; an integrated study of all the parts of the bike, a low position of the centre of gravity. Taglioni’s engines were small, of limited capacity, which was to grow later, with their development. This philosophy dates back to the English school, concrete and pragmatic, to which Fabio Taglioni got inspiration from the start. We mustn’t forget that the British bikes, up to forty years ago, were absolutely the state of the art for performance and technique, and whoever wished to build a bike that was fast on the road or on the track, had to deal with them beforehand.

Taglioni’s motors were single cylinder first, L twins later, and there was never a wide engine, cumbersome and heavy (…excluding some annoying faux pas!!). But singles and twins require large capacity cylinders, and large capacity cylinders require big and heavy valves to breathe properly, and here’s where the convenience of the desmo valvegear is felt: the Ducati singles went like twins and the twins go today as fast as fours. Modern valve springs technology changed a lot in fifty years, but this doesn’t reduce the merits of Taglioni’s brilliant idea. Mind, the Ducati desmo was not the first, and is not the only spring-less valve actioning system, but it is certainly the most rational and simple, and the only one ever applied to production motorcycle engines. Taglioni’s single cylinder motors were but one motor: it was born with a capacity of 100 cc and grew to 440 cc with few changes. Taglioni’s twins were once again all variations on the same motor, obtained by drafting a second cylinder to the single’s basic design. The first twin was born of 750 cc capacity and grew to 1000 before a new revolutionary project was born in 500cc capacity. This new motor was an evolution of the original twin that was to have a long and fruitful life during which it would grow twice the original capacity and four times the original power!

At the end of the ’60s the Ducati management commissioned to Fabio Taglioni a bike of at least 750 cmc, able to stand head with the British and Japanese competition. Will he make it? You bet. When it was time to go beyond the single cylinder motor, the British designers remained prisoners of their own ideas, devising parallel twins, and the Japanese followed the road of the powerful but cumbersome inline fours. Ducati, thanks to Taglioni’s genius, went down a more original road, certainly not an easier one, but which revealed to be proficient: the 90° V Twin (or “L” twin), placed lengthwise in the frame: just a little wider than a single, to the point of almost having no need for a fairing, with a sequence of advantages in terms of lightness and stiffness.

The crankshaft was virtually that of a single, hence stiff and light: it just had room for two rods placed side-by-side. All the bottom end of this twin was not distinguishable from that of a single except for having two holes for the cylinders. The cylinders were placed at 90° one in respect to the other, and the conrods were side to side on the same crankpin. This setup was applied first to the 500 GP then to the production 750, and received its spectacular launch with the victory and placement of Smart and Spaggiari at Imola in 1972. The 90°V cylinders represents the best in terms of many of the dynamic carachteristics of an engine; the crankshaft is short and rigid, the engine vibrates negligibly (for a twin!), balancing is very good, allowing for a lighter frame. Too bad that the “L” twin motor has the disadvantage of being a bit long, with that cylinder protruding ahead!

The 90°V twin has a perfect balance of the inertial forces of the first order. When one piston reaches a dead centre, and must lose all its kinetic energy to invert its motion, the other is half way through the bore and has the highest kinetic energy. Part of this energy is “fed” to the other piston smoothing out the motion and requiring only a very small flywheel. The engine was barely wider than a single of 1/2 its capacity and had one cylinder placed horizontally and one vertically. Sounds odd, but it guaranteed the best airflow for cooling and lots of space where to place carburettors and exhausts. The resulting bike, with one cylinder poking behind the front wheel and the other dangerously pointing at the rider’s crotch, was deemed “funny”, “unruly”, “long”, “un-elegant”, “impossible to dress”. It was definitely apart from the mainstream Italian design of the time, so careful to the balance of shapes and the elegance of design. But somehow, it was beautiful. Something in it showed a perfect balance of elements, of voids and fulls, of angles and lines.

Clearly, Taglioni’s motoring genius could not end with a valve actioning system: he knew that power had to be produced somewhere and the engine had to be able to exploit to the best the advantages of a valvetrain that allowed it to rev faster than the others. Taglioni accurately designed the fluid dynamics of manifolds and combustion chambers: in his last designs the fluid current enters the cylinder twisting in a spiral and reaching the speed of sound; the engine fills up with great efficiency even at low revs, it can bear enormous carburettors and produce a power that, if it is not at the same level of a more fractioned motor, it doesn’t lose much in comparison, particularly since it is obtained with a great efficiency, that is little weight, little heat and little consumption. The rest of the engine is clearly dimensioned to withstand these performances and particularly the exuberance of torque. Thanks to these choices the Ducati twins, as the singles before them , were able to grow in capacity and power beyond expectation.

The “Taglioni philosophy” also involved the design of frames and cycle parts and, once again, Taglioni looked at the masters in the field: the British. A motorbike, for him was not an array of parts but a single complex entity. But this was not enough: the bikes designed by Taglioni were art: the engines were beautiful, the frames were beautiful, and often his bikes are better looking without the bodywork (which was usually designed by someone else, taking into account the taste of the times). At the end of the ’60s his traditional “single backbone” frames gave place to a similar frame but with a very rigid central “cage” holding the swingarm, then came a trellis frame with the engine hanging below it. At first this type of frame was built in UK by the specialist Colin Seeley for the racing bikes, then it was re-designed by Taglioni and made at Ducati. It was soon fitted to the whole production of twins, with the further finesse of the swingarm pivoted on the engine crankcases. Still today, no concession is made to the fashion of big aluminium square spars but only good quality steel tubing is used.

Taglioni remained at Ducati as designer in chief until 1985, when his heritage was taken over by Massimo Bordi who designed the 851, with liquid cooling and four valves that Taglioni, conservative genius, never liked. The Pantah was Taglioni’s last complete design and is the ancestor of all the Ducatis of today, at almost twenty five years from its creation. This motor has been used (and still is…) to power winning road racers and African desert raiders, sport street bikes, sedate tourers, enduros and US custom bikes, not to mention the most successful superbike of all times. To cope with Ducati domination in WSB races, its competitors had to design… a better Ducati! Like the single before, this engine showed an outstanding versatility, only that in these times of extreme specialisation it’s a much more admirable achievement! A Taglioni-inspired trellis frame is still the trademark of all modern Ducatis, along with the 90° V twin engine and the desmo valvetrain. Speak of long lived ideas!

the modern WSB Ducati shares so much with Taglioni’s original design of the Pantah of 1977, that it can be considered an evolution of that bike. Until the 90s the crankshaft was virtually the same as was drawn by Fabio Taglioni for the Pantah, only that the new engine had more than twice the horsepower of the original design. And Taglioni’s Pantah was all but oversized: it was simply well designed. And the Pantah was simply an evolution of the bevelhead “L” twin (with a few breakthroughs like the crankshaft in one piece and the rubber belts to actuate the camshafts), which, in turn, was simply an evolution of the bevelhead single.

Fabio Taglioni’s work was just that: refining a good design so it can become better. Revolutions can wait. Or left to be done by others. Perhaps his passion for orchids has had a part in shaping his way of thinking: you can’t make a “revolutionary” new orchid: you must cross breed and improve the genes until it is just perfect. Taglioni’s bikes are just that: orchids in the forest of motorcycle design.

Fabio Taglioni died on July 18th, 2001, aged 80.

(LG)

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