It’s fair to say that anyone who attended the Roger Dubuis presentation at SIHH 2017 will agree the Geneva brand is taking its slogan ‘Dare to be rare’ rather seriously. Consider the new Excalibur Quatuor Cobalt MicroMelt, which uses a high-performance cobalt chrome alloy produced though a complex metallurgical technique, a first in the industry.
The brand also unveiled a partnership with Pirelli, Formula 1’s official tire supplier, to produce rubber straps made from the actual tires used in Formula 1 races in a series of limited edition watches. However, the showstopper this year was the Excalibur Spider Carbon, the first mechanical wristwatch with not only its case, but also its movement plate, bridges, and tourbillon upper cage made entirely of carbon.
This isn’t the first time that Roger Dubuis has combined traditional watchmaking with contemporary new materials. The brand has introduced carbon in watches like a Black Velvet (on the case and dial) and used a forged carbon case on the Excalibur Automatic Skeleton Carbon range (unveiled last year), but the use of carbon in the construction of the movement has not been attempted before.
“The idea of this innovation is that it should add some advantage to the customer’s experience of wearing the watch. We have three different axes when it comes to innovation – firstly, it needs to be light and extremely wearable, second is durability and resistance to wear and tear, and finally, it needs to be a rare and precious material,” says Gregory Bruttin, the brand’s product strategy director.
“The use of carbon was mainly led by the fact that it would make the watch really lightweight and comfortable. After all, the majority of the weight of a watch is the case,” says Bruttin. To drive home the point, he places three Excalibur watch cases in my palm, one by one. The first is made in gold, the second in titanium and finally the case of the Excalibur Spider Full Carbon. There is a palpable difference in weight, even as the three cases are casually placed in the palm of my hands. “That is because carbon fiber is 10 times lighter than gold and two times lighter than titanium,” says Bruttin.
Most carbon cases feature a checkerboard pattern consisting of woven sheets of carbon fibers that are layered and bonded with a polymer resin. On the Excalibur Spider Carbon, Roger Dubuis uses multi-layered carbon with a pattern of horizontal lines that leave a pin-stripe-like effect on the case, lugs and movement. To achieve this look, the carbon parts had to be cut at an angle of 10 degrees. “The stripes you see is because the carbon fiber is a composite laminate and uses only 20 per cent epoxy resin. This is better in terms of performance, the only drawback being that it is a lot more expensive to produce. This is also the reason why most brands don’t use this material,” explains Bruttin.
The 45 mm case features a fluted titanium bezel with a black vulcanized rubber. Titanium was used instead of carbon fiber because it resists the high heat required for the vulcanization process. The red accents visible on the bezel is thanks to the use of red lacquer.
These red accents on a black carbon case with those distinct pin-stripes create a sporty, masculine look.
The case also uses a titanium DLC caseback and a titanium DLC crown vulcanized with red rubber.
The watch is powered by the in-house Caliber RD509SQ movement that was designed from scratch. The manual-winding openworked movement has a flying tourbillon at 7 o’clock and is made of 179 components. It features the trademark star motif bridges that also act as hour markers. An interesting and visually striking addition is the presence of a black PVD brass honeycomb grill between the plate and the bridges of the movement. The bridge, movement plate and tourbillon cage are made entirely of carbon and feature the same pin-stripe pattern seen on the case.
Bruttin explains that using carbon in the creation of the upper cage of the tourbillon has more than the obvious weight benefits. There is a 30 percent reduction in the weight of the upper cage, which has led to a 50 percent increase in the power reserve. “I’ll give you an example from the world of motoring – when a car is lighter, it can go further and faster. It’s the same with the tourbillon in this watch, we were able to increase the power reserve significantly because of the use of carbon,” he says.
Caliber RD509SQ carries the prestigious Geneva Seal, a certification reserved for wristwatch movements made in the city or canton of Geneva with special requirements for testing, finishing and decoration of the watch movements. According to Bruttin, one of the big challenges in developing this movement was ensuring it meets the requirements for the Geneva Seal.
Nobody in the industry has polished carbon movement to submit for a Geneva Seal inspection before. Hence, the production team had to create new tools and invent new techniques to decorate this movement. The carbon bridges and movement plate have finely beveled edges. “Carbon cannot be polished, so we could only decorate the movement. If you look closely, you’ll notice that contrasts between the metal and carbon parts on the movement is striking, especially the use of a matte black tourbillon cage,” said Bruttin.
All 28 pieces of this limited edition will have the Geneva Seal and it took the team a year to finalize the process that led to this certification. “It’s very important for us because it’s part of the DNA of the brand. We have used the Geneva Seal from the very beginning to convey the quality of our movements. It’s important to never forget our origins. In the end, it’s also good for the customer, who is assured of the quality. After all the certification doesn’t come from Roger Dubuis but an external party, the canton of Geneva,” says Bruttin.
It took the team two years to develop this movement. I asked Bruttin what has been his biggest learning from working on such a movement. “I would say it’s the realization that using carbon in the bridge of a movement makes it better at absorbing shock. When we redesigned the movement, we made the bridges much thinner as carbon absorbs shock much better. Also the increase in power reserve was a revelation. We didn’t imagine that with a lighter tourbillon cage, we could increase the power reserve by 50 percent. We would have been happy with 25 percent.”
The watch is paired with a black rubber strap with a fabric inlay and a black DLC titanium folding clasp. The Excalibur Spider Carbon is a bold new step for Roger Dubuis. It successfully combines traditional watchmaking with technically innovative materials in a visually striking design. The end result is tangible as soon as you wrap the watch around your wrist. For a 45 mm case, it is incredibly lightweight and comfortable to wear.