Mark McArthur Christie enters the world of ‘Hyper Horology’ in order to review the Roger Dubuis Excalibur Double Flying Tourbillon. The styling of this futuristic timepiece is intended to be ‘excessive’, but beyond its bold styling, the watch harnesses incredible watchmaking and sublime finishing.
Making a tourbillon – the tiny machine-within-a-machine that helps a watch’s balance defy the effects of gravity – is difficult enough. Nearly a hundred parts all need to work together – and with the rest of the watch’s mechanism – for it to be effective. Putting two tourbillons in one watch is a proper horological challenge. To put two flying tourbillons into a three-dimensional skeleton movement is just barkingly brilliant.

George Mallory was once asked, “Why do you want to climb Everest?” His reply? “Because it’s there.” The same view of challenges seems to drive the watchmakers at Roger Dubuis.

The Manufacture has gone even further and regards the double tourbillon as almost its own. And the Roger Dubuis Excalibur Double Flying Tourbillon has (the clue is in the name) two of the things. But why on earth go to the trouble of building a watch with a brace of tourbillons? Isn’t that just, well, showing off a bit?
Bear in mind that the tourbillon was originally designed to overcome the effect of gravity for watches that generally sat either flat on a surface or vertically in your pocket. A modern wristwatch will move around far more, evening out the effects of gravity naturally, so the need for even a single tourbillon is marginal, yet to the team at Dubuis, that fractional difference matters.

Strategic Product Director at Roger Dubuis, Gregory Bruttin, explains the very logical thinking behind it.

“The advantage of a double tourbillon is to increase the frequency of the watch and thus its precision. There is twice as much ticking as in a single tourbillon watch.” So you get two tourbillons each running at 3 Hz (21,600 bph).

Twice as much ticking, certainly, but surely two tourbillons will make the Excalibur twice as fragile? Apparently not. Bruttin outlines the reasons. “This complicated mechanism allows a better resistance to shocks. In fact, the cages are self-compensating and can be adjusted through the differential. For the upper part of the tourbillon cage, we wanted to have a polished bridge with very good elasticity, in order to have an incredible aesthetic aspect but also very good resistance to shocks. The cobalt chrome that we have been using for many years at Roger Dubuis Excalibur Double Flying Tourbillon has the advantage of being twice as elastic as steel and having an incomparable quality of polishability. This is really a technical feat that has a real interest for the client in terms of daily use.”
Roger Dubuis really is serious about daily use. These are distinctive watches, sure, but they’re meant for putting on your wrist and wearing, not just looking at in the watchbox. And, as striking as the range of cases is to look at, the heart of the whole thing is the skeletonised movement.

Let’s be honest. Skeletonised movements can sometimes be a bit, well, naff. They’re often just conventional movements with metal machined out of the plates. Clever enough – one has to know exactly how much torsional rigidity is needed to prevent the whole plot from buckling – but still potentially just a bit underwhelming. Not here. The Excalibur’s movement is designed from scratch as a skeletonised structure. The trademark Dubuis five-pointed star holds the (skeletonised) mainspring barrel and part of the gear train. The same motif is picked up by the tourbillon bridges and repeated on the bottom bridges. And ‘structure’ is the right word; looking down through the movement is like looking down through a multi-level cityscape.

This is Dubuis’ RD108SQ. Product Director Bruttin says although it looks superficially like a slight evolution of the RD01SQ, the new movement is substantially different. He explains, “This is a total redesign of our initial product at the technical and aesthetic level. It was taken into consideration with the evolution of the last 15 years and the expectations of our customers…. We strive to ensure that our timepieces are always at the forefront of these two elements, which is the case with this radical evolution of our iconic double tourbillon.”
The new movement features an extra 18 components and four jewels over the RD01SQ. That doesn’t sound like much, but in watch terms, it’s a very significant change indeed. You’ll find the new jewelled bearings mostly in the tourbillons’ differential – the link between the two balances. The extra 18 components are in the flying tourbillon cages.

Bruttin gives an insight into some of the detailed changes within the RD108SQ, “This increase in parts has been possible thanks to our know-how acquired over the last 15 years: we have completely rebuilt our differential to optimize its operation. We have also reviewed the entire tourbillon cage and most of the components have been replaced by titanium, which allows us to lighten it so that it resists shocks better.” It’s worth bearing in mind that these are improvements to a 5p-sized part of an already accurate watch. It’s a level of detail-obsession that’s like Bentley choosing to manufacture speedometer needles from titanium to save weight. The Roger Dubuis Excalibur Double Flying Tourbillon team have focused on two further areas with the new movement: resistance to magnetism and power reserve. For a start, they’re maximising their use of titanium as a movement material. Not only extremely light, titanium is, in practical terms at least, non-magnetic. This makes it ideal for movement components, especially as they’re likely to spend plenty of time around modern mobile phones and laptops which emit numerous magnetic fields.

Lighter components also need less energy to move. One might think watch components are already so small and weigh so little that any improvement in power reserve would be fractional. Not so. In fact, the RD108SQ’s power reserve is now 72 hours, up from 42 hours. This means the watch can be removed from the wrist at the start of the weekend and it will be still ticking on Monday morning. And the movement is, of course, fully skeletonised – a Roger Dubuis trademark. As Bruttin says, “Our approach in terms of development is certainly different from other brands. Aesthetics is a goal in itself and not a consequence of design and we aim for a perfect design and adapt the design accordingly. We have always paid great attention to the aesthetics of our movements, which naturally made us evolve towards skeletons. Our builders in addition to the engineers are also designers, so they pay attention to every detail and constantly find solutions to achieve unique designs.”

Unique indeed – for example, the colour and finish of the movement plates and bridges are down to NAC coating. Bruttin explains, “NAC is a galvanic treatment that we developed, with a partner, during the launch of the first version of the double skeleton tourbillon. This surface treatment has many advantages, the main ones are first of all its colour, the charcoal grey has the advantage of supporting the rendering of the Geneva pin terminals that we apply on the bridges, then the reflection of the polished parts. As you look at the watch it passes from a black polish to white which is particularly spectacular.”

There’s a level of wholly healthy and horologically focused obsession with these watches. And it even extends to the lubricant in the movements. Normal lubricants are, along with the rest of the watch’s moving parts, usually hidden safely in the dark behind the caseback. Once they’re out in the open, they’re exposed to ultraviolet light. This is not good for watch oils, accelerating the speed at which they break down and lose their effectiveness. So rather than simply reduce the service interval for the watch, Bruttin’s team have worked specifically on the movement’s lubrication to correct this weakness. He says “We have also taken advantage of this to improve the performance of our lubricant and this has meant a better power reserve and a better stability of functioning over time.”

The cases of the Excalibur watches are no less unique. Nothing as dull as stainless steel here. There’s a choice of white or pink gold. But the 45mm pink gold cases on the RDDBEX0920 and RDDBEX0822 are made from a gold that is not only a special shade, but has superior hardness to that of standard gold and a colour that won’t change over time. You can choose your level of bling – in a thoroughly appropriate and Roger Dubuis way – ranging from ‘plain’ white gold in the RDDBEX0819 right the way through to the full-on diamondtastic, baguette-studded case of the 0822. There’s a limited production run of just 8 watches of each type. It’s hard to sum up the Roger Dubuis Excalibur Double Flying Tourbillon. It doesn’t so much break the usually restrained design rules of Haute Horlogerie as roll them up, put its feet on their desk and use them to light a Cohiba. Yet, at the same time, the level and standard of finishing, engineering and watchmaking are at the top of the pile. It would come as no surprise to find that the inside of the mainspring was hand-engraved with a street map of Geneva.

There’s more to the Excalibur Double than just the desire for sheer Haute Horlogerie cleverness for its own sake or to make a watch that is spectacularly unsubtle. It’s an absolutely proper watch; every element has a function and a purpose that’s been planned, thought-through and executed from an engineering standpoint, not just for show.

Yes, the Excalibur’s double tourbillons are full-on aesthetically, but they’re also full-on horologically. And that’s perhaps what makes them so special.