Vee Two Ducati Alchemy SV-1 - Modernized Aussie Bevel Head

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Every few years we in the Ducati community have a crisis when the latest generation of Ducs are unveiled. Inevitably the old hats and stodgy luddites will bemoan the commercialization of the company and how it has lost its way compared to back in THEIR DAY when they build the best goddamned bikes with no nevermind paid to profitability (or reliability). It happened when they dropped the dry clutch. It happened when the 1199 eschewed all the traditional Ducati traits. It happened when Pierre Terblanche was given free run in the design department. Hell, some purists claim the last real Ducatis rolled off the line in 1983 before Cagiva got their meat hooks on the brand.

So it was in the 1980s when the Pantah rubber-band motors started replacing the bevel drive twins and the purists moaned that Ducati had lost its way.

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Some context is in order, for those of you who aren’t well versed in Ducati history. Ducati initially made its name in racing and on the street with single-cylinder bikes. A talented engineer by the name of Fabio Taglioni joined the company after jumping ship from Mondial in 1954 and developed a unique desmodromic valve system to combat valve float at high rpm in racing motors. Desmo soon found its way into the road going singles and became a signature of the marque. These four-stroke singles, available with desmo and “conventional” valvetrains, used a bevel tower driven overhead cam, which has a distinctive tube topped by a triangular housing on the right side of the engine. A set of bevel gears in the crankcase rotate the shaft, which turns the cam above through another set of bevel gears. Hence the “bevel head” nickname.

Bevel

When the company needed a larger displacement model in 1970, Taglioni had the bright idea of mating two of these singles to a common crankcase with a 90 degree “L-Twin” configuration. Thus the 750 GT, and the bevel twin, was born. After a surprise win at the Imola 200 in 1972, Ducati’s future association with twin-cylinder superbikes was assured.

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These bevel engines would become some of the most iconic and sought after motorcycles of all time. The desmo singles would become cult machines on the road and the track, while the bevel twins would become blue-chip investments for those fortunate enough to lay their hands on them.

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In 1975 Ducati would introduce an upsized twin, the 864cc 900 “square case” models that would endure until the mid-80s, culminating in the final Mille (973cc) models which ended production in 1986. The so-called rubber band models, the genesis of Ducati engines of the 80s-90s and 2000s, would be introduced in 1979 as the Pantah twin. 

Pantah

Designed by Taglioni as a more cost-effective, efficient replacement for the ageing bevel heads, the Pantah motors were four stroke 90 degree twins that used a belt-driven overhead cam (designed for desmo from the start, whereas the bevel heads originally used conventional valves) and took advantage of modern production methods to cut down on assembly time and production costs. The Pantah would become the basis of all modern Ducati motors built up until the Testastretta introduced a clean-sheet design in 2001. 

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The bevel heads were notoriously difficult to assemble, requiring careful shimming of many major assemblies by trained workers. You can’t just slap a bevel motor together. As such they tend to have a reputation as “hand-built” motors among purists who see the Pantah mills as mass produced junk. The fact that early Pantahs were wimpy 500-750cc (with 350cc home market models) and the bevels were a far more burly 864-973cc probably helped contribute to the myth, even though the smaller Pantahs were matching or exceeding the power thumped out by the bevel motors.

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So there was, and still is, a dedicated bevel head following that sings the praises of these early twins, rationality be damned. People fawn over old Norton Commandos and Triumph Bonnevilles like they are the first and second coming of Christ made metal, so bevel-nuts aren’t the only obtuse old-bike-curmudgeons with no regard for modern iron. To their credit the bevel-nuts chose a worthy object of affection, as these mills have a reputation for sweet running and a broad spread of power. The hand-built nature of the bevel motor is as much a curse as a mark of quality. I’m acquainted with Ducati tuner Guy Martin of MBP Ducati, and he put it quite succinctly – he quotes 20 odd hours to rebuild a Pantah-type engine, 40 plus hours for a bevel. And he admits he is understating the hours for a bevel because no one would pay for the time it actually takes him.

Getting back to the topic at hand -

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Lets say you are a dedicated bevel head aficionado but want something more modern than what the mid 1980s could offer in terms of frame and suspension design. You want an old-world motor in a new-world chassis. You want a bevel twin that can spank those smug punks on their chintzy rubber-band Ducatis. You want an Alchemy.

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The Alchemy was a custom chassis kit offered by noted Australian bevel specialist Brook Henry, who began tuning Ducs for the road and track in 1979. In the Ducati community Vee Two has become a byword for hot rod Ducati parts. Brook made a name for himself as one of the premier Duc tuners and used to offer a staggering catalogue of mouth watering parts for all generations of Ducatis from the 70s to 2000s. Since then he has sold and then re-acquired Vee Two and re-organized the business to focus once again on his original specialty – building trick bevels.

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In the 90s Brook offered the Alchemy as a complete bike or a kit chassis. The project began in the late 80s as Vee Two discovered that their highly tuned bevel motors were overwhelming the standard Ducati frames. The only way to tame wayward handling and keep the power in check, and allow the use of more modern suspension components at both ends, was to develop a bespoke frame.

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Custom frame builders have been around for ages, some have become legendary in their own right. Greeves, Seeley, Harris, Rickman, Bimota, Egli, Reynolds, Bakker – all offered custom frame and suspension kits that would bolt up to existing motors for the well-heeled racer who demanded the best chassis components to wrap around their stonking motors. Egli and Bimota went on to build complete high-spec bikes around outsourced motors, bikes that ended up being more desirable than the donor machines ever were. So in this regard Vee Two was not the first, but it was one of the only companies to provide a kit for a Ducati bevel engine (Harris also produced one in the early 90s called the Monomille).

Image Source Note that this later version of the RV-1 has a specially built bevel motor converted to belt-driven overhead cams, an idea Brook Henry tinkered with in his quest for more power.

In 1988 Brook and Stuart Barrowclough teamed up and designed the RV-1 (Racing Vehicle) special, which they successfully campaigned in Australian road racing with a brief stint at Daytona where they ran as high as fifth until mechanical failure intervened. The RV-1 would serve as the template for the later SV-1 (Street Vehicle) kits and was an impressive upgrade over the stock Ducati frames. Like the standard bevel frames, the engine is used as a stressed member in the chassis but with much more aggressive triangulation around the front downtubes and heavily reinforced laser-cut steel mount plates at the back with rear-set control mounts. A twin spar design allowed much easier access to the rear cylinder for maintenance (a flaw with all bevel Ducs). The really trick part was the monoshock rear suspension with a rising rate linkage mated to a custom box-section swingarm - light years ahead of the antiquated tube section swingarm and dual shocks you'd find on the original frames. The shock was mounted near horizontal, pivoting off the left hand frame spar with a long linkage running to the swingarm. This allowed Vee Two to maintain a short wheelbase and give easy access to the rear cylinder.

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The SV-1 was introduced in 1991 as a kit, with several complete bikes produced and registered by Vee Two - 7 in total. 3500$ AUD got you a frame, swingarm, WP rear shock, fuel cell, and unpainted fibreglass bodywork. The SV kit had a VIN number and mounts for street equipment, while the RV kit was not intended for road use and had no such provisions (and apparently used chrome moly steel, instead of the mild steel used on the SV frame). The fuel tank was a seperate cell that was hidden beneath the bodywork. The owner/builder supplied the remainder of the parts from a donor machine, which could be any Ducati bevel twin built from 1970-1986. At the time you could order a pallet load of hot rod parts from Vee Two to turn your old Duc into something really spectacular, given unlimited funding. Antiquated though they are, bevels are pretty robust mills and can betuned to impressive levels… As the old saying goes: speed costs money - how fast do you want to go? 

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With the Alchemy kit handling was transformed and brought up to modern standards, eliminating the old Ducati quirk of slow and obstinate handling (“stable”, as some would say), a result of conservative frame geometry combined with a long wheelbase. A significant reduction in rake and a lot more chassis stiffness, plus the modern rear end, contributed to very tidy handling. And the stiffer frame and swingarm were capable of handling the power of a tuned bevel motor, making it an ideal package for vintage racing (if the rules allowed it, anyway). If you stuck to the standard kit idea you would use your original front end and wheels, but offset triples were available from Vee Two to allow you to bolt modern forks on to further enhance the roadholding.   

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As a kit bike, no two Alchemys are alike. Depending on the donor bike, the optional upgrades, and the owner’s taste, Alchemys you come across today can range from gentleman roadsters to fire-breathing racers. The kit included bodywork that combined a bikini fairing, (dummy) tank, and solo/dual tail section into a single flowing assembly that looked remarkably OEM for something concocted in a shop in Perth.

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All told, 97 kits were produced in addition to the 7 complete bikes built by Vee Two. That makes the Alchemy a rare bird that is only known among Ducati cognoscenti, or anyone fortunate enough to run into an SV-1 owner. As a DIY bike, odds are many of the kits are gathering dust in back rooms or are languishing as half-completed projects. Indeed, information about the SV-1 is scarce and owners are few and far between (most Alchemys seem to have remained in Australia, with a few that made their way to Europe). In addition to the “production” models, an updated Alchemy SV-2 prototype was reportedly built. Supposedly it is still owned by Brook Henry, but details (and photos) are virtually nonexistent.

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To make matters worse, Vee Two was bought out and closed their Ducati operations several years ago, which meant that most of their stock of parts was sold off. The SV-1 frame and bodywork jigs were reportedly destroyed at some point before the buyout, which makes the existing kits all the more special. Today Vee Two’s Ducati operations have been restarted by Brook Henry, albeit in far more limited capacity. Those of us who remember their prior selections of trick parts, and their cool custom bikes like the Alchemy and their later Squalo series (a future OddBike feature), are eagerly awaiting the company’s return to form.

  

... And for the record I think Ducati lost its way when they discontinued the 916 series and introduced the 999.

Interesting Links

Period introduction to the Alchemy SV-1
The Vee Two website

Some excellent studio photos of the SV-1