Roger Dubuis Excalibur Monobalancier EON Gold Watch Review
Angus Davies gets hands-on with the Roger Dubuis Excalibur Monobalancier EON Gold. In this feature, Angus examines the composition of the watch, chats to key personnel and reflects on what he learned about the prestigious Manufacture after visiting its site in Geneva.
Roger Dubuis
Samuel Langhorne Clemens, better known as Mark Twain, once said, “continuous improvement is better than delayed perfection.” However, at Roger Dubuis, it is the notion of continuous improvement that drives the company’s engineers and watchmakers to pursue absolute perfection with unrelenting zeal.
Earlier this year, the Genevan Manufacture unveiled the Roger Dubuis Excalibur Monobalancier EON Gold, seemingly, at first glance, a subtle evolution of its predecessor. However, when thoroughly appraised, the new model delivers a plethora of refinements.
Roger Dubuis Excalibur – a rising star
The star-shaped bridge, a design staple of the Manufacture has been reworked. The former bridge served both aesthetic and structural roles, sat deep within the case and was decorated with beautifully defined perlage.
On the new Roger Dubuis Excalibur Monobalancier EON Gold, the star has risen from ground level and now sits on the top floor, close to the sapphire crystal, floating above the barrel. The star no longer plays a structural role, however, the torsional rigidity of the movement remains beyond reproach. This stylistic change accentuates the differing depths of each movement part, thereby heightening the visual appeal of the dialscape.
Roger Dubuis has introduced a ‘new generation of finishing’, that is more consistent with the brand’s contemporary flair. The perlage found on the previous star-shaped bridge has been supplanted with a combination of sandblasted, satin-brushed surfaces and polished angles. These finishes are widely employed throughout the model. The Manufacture sought the approval of the Poinçon de Genève prior to adopting the changes. Modernity has not come at the expense of traditional craftsmanship, something evident when holding the watch in one’s hands.
Roger Dubuis Excalibur readability
A problem that often afflicts skeleton models is the hour and minute hands can become lost in a sea of bridges and components. Thankfully, no such issues afflict the readability of the Monobalancier’s indications. The openworked mainplate and bridges are executed in black, playing a deferential role to the golden hands and indexes. The skeleton theme is reinforced with the split hands and the v-shaped indexes, yet both elements still remain notably legible.
A minute track is presented on the flange encircling the dial area and is executed in a brushed black finish. This is a watch that looks decadent, excessive, but eminently wearable, making it perfectly suited to daily wear.
The RD720SQ calibre
The architectural character of the Roger Dubuis Excalibur Monobalancier’s movement, the new RD720SQ calibre, invites the wearer to dive in and survey the interior of the watch. Many of the parts within the watch, there are 172 movement components in total, are freely shown. Each part is beautifully finished, upholding the requirements of the Poinçon de Genève.
Image – Roger Dubuis Excalibur Monobalancier EON Gold RDDBEX0953
Part of the charm associated with this genre of watch is that numerous parts, typically shrouded by a dial, are disclosed for the delectation of inquisitive souls. As its name suggests, the Monobalancier features one balance wheel unlike some of its siblings endowed with two or even four balances. The spectacle of seeing the balance wheel perform its favourite dance, oscillating to and fro, proves captivating.
Roger Dubuis Excalibur Monobalancier EON Gold – a new micro-rotor
Considering the vast number of watch brands on the market, it may seem surprising to learn that few companies produce timepieces equipped with a micro-rotor. A regular rotor, usually positioned to the rear, will cover approximately 50% of the movement, a characteristic incompatible with a skeleton watch. Moreover, a conventional rotor increases the thickness of a movement and hinders the wearer from viewing the various finely decorated components.
At this juncture, you may ask why all watches are not equipped with a micro-rotor. The challenge is that the motion of the micro-rotor needs to create sufficient inertia to energise the mainspring. Only a few Maisons have surmounted this technical obstacle. Needless to say, Roger Dubuis has amassed vast experience producing watches equipped with a micro-rotor.
However, consistent with its ethos of continuous improvement and its unwillingness to accept the status quo, Roger Dubuis has revisited the micro-rotor fitted to the former model. In terms of the new Roger Dubuis Excalibur Monobalancier EON Gold, the micro-rotor is made of 18ct pink gold and tungsten.
Image – Roger Dubuis Excalibur Monobalancier EON Gold RDDBEX0953
Interestingly, tungsten has a greater density and by using it, Roger Dubuis is able to generate more inertia. But, nothing is quite as simple as that, the engineers, based at the Manufacture, have expended much energy improving the efficiency of the winding action and minimising the potential influence of vibrations. Roger Dubuis continues to employ some 18ct pink gold for the rotor, but this is used primarily for aesthetic reasons. The addition of the Roger Dubuis logo tops off the new, improved micro-rotor.
Roger Dubuis Excalibur Monobalancier EON Gold – transfer of energy
After the micro-rotor has harvested energy from the natural motion of the wearer’s wrist or from manually winding the crown, it must be stored. A barrel, incorporating a mainspring, serves as a repository for the energy. The tensioned mainspring within the barrel harnesses a significant amount of energy. This needs to be stepped down in the same way a transformer steps down an electrical current. If the energy from the barrel was unleashed without any braking effect, it would become depleted very quickly and various small parts may also suffer damage.
Image – Roger Dubuis Excalibur Monobalancier EON Gold RDDBEX0953
The teeth on the barrel engage with the centre wheel and then a series of additional wheels thereafter termed the gear train. The gear train reduces the intensity of the energy serving the balance. A problem that afflicts many watch movements is the energy consumption of the gear train due to frictional losses sapping power and compromising efficiency. However, the team of watchmakers and engineers based at Roger Dubuis, headed by Gregory Bruttin (Product Strategy Director) have mitigated this potential issue by employing their combined talents in order to deliver greater efficiency.
When the power eventually arrives at the escapement and regulating organ, the issue of efficiency rears its ugly head again. However, with the new RD720SQ calibre, the great minds in Meyrin have mitigated energy loss.
Roger Dubuis Excalibur Monobalancier EON Gold silicium
The escape wheel is formed of diamond-coated silicon. This glass-like material has low-frictional properties which, in combination with a newly developed lubricant, mitigates wear and consumes less energy. Furthermore, silicon can be formed into intricate shapes. In this instance, the geometry of the escape wheel has been optimised, again delivering superior efficiency.
Usually, the pallets fitted to a pallet lever are made of synthetic ruby (aluminium oxide). Roger Dubuis has, once more, shown its predilection for innovation. On the new RD720SQ calibre, the pallets are curved and made of diamond-coated silicon. Each element of the escapement has been maximised to deliver the best performance.
The fastidious mindset of the Swiss marque is evident when appraising the appearance of the escape wheel and pallets. Ordinarily, silicon components appear purple, however, the personnel at the high-end brand did not like this hue, so they chose to dye the parts to make them look more pleasing to the eye.
Ultimately, the efforts of the Genevan Maison have led to an increase in efficiency and energy transmission.
Gregory Bruttin explains that the new escapement is 20% more efficient than its predecessor and the balance wheel inertia has doubled, improving rate stability and mitigating the regulating organ’s sensitivity to shocks.
Roger Dubuis Excalibur Monobalancier EON Gold – hyper contemporary design
‘Hyper contemporary design’ is a term familiar to Roger Dubuis devotees. The Manufacture wholeheartedly embraces modernity, repeatedly delivering thought-provoking aesthetics, fusing the hitherto discrete domains of micromechanics and habillage.
With the advent of the Roger Dubuis Excalibur Monobalancier EON Gold, the Maison indulges its passion for daring, unapologetically excessive styling. There is nothing conventional about this watch. It does not emulate the work of others, it’s distinctive and slightly offbeat.
Measuring 42 mm in diameter, the Monobalancier is housed in EON Gold. Consistent with other forms of 18-carat gold, it is 75% pure. However, the remaining 25% of the material has been modified, making it ‘more resistant to tarnishing when exposed to extreme conditions.’
When appraising the case, noting each clean-cut line and every curving form, one cannot fail to notice the Monobalancier’s crisply defined torso. For example, the fluted bezel is sharply outlined, free of flabbiness and entices a curious index finger to repeatedly touch its form. The crown repeats this fluted design, delivering a tactile experience par excellence.
Image – Roger Dubuis Excalibur Monobalancier EON Gold RDDBEX0953
Since the inaugural Excalibur was released in 2005, some design elements have remained eg the model’s unusual lugs. These feature an additional centrally positioned arm that helps unite the strap and watch head in steadfast union. No one can accuse Roger Dubuis of plagiarism.
Closing remarks
With a Roger Dubuis Excalibur Monobalancier EON Gold affixed to my wrist, I rubbed its fluted bezel and reflected on my time at the Manufacture.
My experience began in T0, an area of the Manufacture where metal bars and square plates were processed using a combination of CNC, profile turning and wire erosion machines. Thereafter, parts were cleaned and then subject to various types of protracted finishing. Eventually, a parts kit would arrive on the watchmaker’s bench where the painstaking process of assembly would ensure. Thereafter, the watch was regulated and then subject to an exhaustive array of quality controls. And all the while, everything was liable to the independent scrutiny of the Poinçon de Genève.
However, as I discovered from chatting with Gregory Bruttin, the previous paragraph does not adequately convey the work of the engineers and watchmakers who relentlessly push the performance envelope. This team of exceptional individuals continuously look to the horizon, tirelessly travelling to a place called perfection. It’s a destination that will forever remain elusive, just beyond their reach, however, nobody has told the team at Roger Dubuis, a brand that never ceases in its quest for the perfect expression of Hyper Horology. A star is born.
Further reading
Technical specifications
- Model: Roger Dubuis Excalibur Monobalancier EON Gold
- Reference: RDDBEX0954
- Case: EON GOLD; diameter 42 mm; water resistance 10 ATM (100 m); sapphire crystal to the front and exhibition case back.
- Functions: Hours; minutes
- Movement: RD720 calibre; self-winding movement; frequency 28,800 vph (4Hz); 32 jewels; power reserve 72 hours.
- Strap: Pink gold cover with titanium blades, triple folding, interchangeable with Quick Release System – QRS.
- Price: £68,500 (RRP as of 13.10.2023)