Greubel Forsey has unveiled its first models to feature a case constructed entirely of carbon fibre. The two limited edition models are lighter, more compact and more durable versions of the Double Balancier Convexe and Balancier Convexe S2. Since carbon fibres are never combined twice in the same way, the design of each piece will also be unique.
To achieve the complex geometry of the two case designs, the carbon fibre developed by Greubel Forsey for the new models required 16 tonnes of pressure to be applied during the production process. That is 8 times more than the 2 tonnes required for conventional case designs. Also, by multiplying the layers of carbon, each of which measures 1 to 5 microns, Greubel Forsey has obtained a much denser carbon case than is standard.
Double Balancier Convexe Carbon
The Double Balancier is Greubel Forsey’s sixth ‘Fundamental Invention.’ Its prototype mechanism, patented in 2007, was first proposed as part of an ‘Experimental Watch Technology’ project, in which the two regulating organs were superimposed and inclined at 20°. A second calibre of just six timepieces followed close behind, with the two regulating organs positioned on three-dimensional planes and inclined, this time at 35°.
In 2016, Greubel Forsey presented the invention in its current form: the two balance wheels are arranged side by side, inclined at 30°, and linked by a constant spherical differential visible between 6 and 7 o’clock. In each 4-minute period, it halves the margin of error, thus meeting the performance, precision and reliability requirements that Greubel Forsey sets for all its timepieces.
The Double Balancier Convexe in carbon, a limited edition of only 22 pieces, has a smaller diameter of 42.5mm, offering collectors a more compact and lighter watch with higher resistance to wear and tear. The carbon used in the construction of this watch is both flexible and solid, with fibres between 1 and 5 microns thick. This timepiece has a considerably more modern feel when compared to its peers. This is also the reasoning behind the reduced diameter of the case.
On the case back, its form complements the curve of the wrist. On the dial, a three-dimensional, curved profile allows the movement to fully express itself. The new material opens up the possibility of executing fine watchmaking finishing, from satin to matt and relief engraving. Each of these complements the natural work of the carbon fibres that match with the converging lines on the Convexe case.
Greubel Forsey offers two carbon Double Balancier versions in carbon. The first features a dominant iridescent green finish, with numerous rich blue hues to the main bridge incorporating the power reserve display, as well as the mainplate and the hour ring. This is complemented by a rubber strap in the same tone. The second version brings black to the fore, asserting the timepiece’s elegant simplicity.
In contrast to the homogeneous carbon fibre weaves, the hand-finished movements in both the green and black versions stand out with their mirror polishing, sharp internal angles, straight and circular-grained surfaces, and curved hands with luminescent tips.
Balancier Convexe S2
Like the Double Balancier, the Balancier Convexe S2 in carbon has been redesigned in a more compact case, with a diameter of 41.5mm, and is presented in two limited series of only 22 pieces each. Each case is unique thanks to the arrangement of its fibres, which align with the curvature of the case. This timepiece hugs the wrist perfectly as its case is convex on the case back as well as the display side.
At 12 and 6 o’clock, the two converging lines give the Balancier Convexe S2 a 3D geometry of high complexity and volume. It gives way to a vast open space under the sapphire crystal at 6 o’clock. Within, the 30° Inclined Balance Wheel has been completely redesigned to fit the new proportions of the carbon case.
The new Balancier Convexe S2 has stuck to traditional finishes for the case, lugs and crown, with the bezel and lugs alternating between matt and grained finishes. The crown asserts a bold matt finish with particular attention accorded to the precision of its “GF” initials engraving.
Between 3 and 4 o’clock is the double open-worked “arched” bridge. Its train of wheels below seems somehow suspended as if in a void. With its patent filed in 2019, the bridge has also become one of Greubel Forsey’s signatures. It embodies an extremely high level of finish on the titanium components (which are notoriously difficult to polish), with multiple sharp internal angles.
The 303-part hand-wound movement, delivering a 72-hour chronometric power reserve, has an exceptionally well-defined architecture, with three large hand-decorated bridges on the movement side. The grained bridges and main plate are perfectly harmonised with the carbon case. The cover of the twin barrels features a black treatment in keeping with the case and carbon plate. The relief engraving on the 3D barrel cover blends seamlessly into the redesigned case.
The new Balancier Convexe S2 will be produced in two limited editions of 22 pieces each – where the small seconds get either the blue or black treatment, matching textured rubber strap, and a titanium and carbon buckle.
