Carbon is a material that Greubel Forsey has studied for many years. Giving it complex, architectural shapes, all with the highest level of watchmaking finishes, is an exercise that requires patience and technical mastery. Now, the conditions are ripe to give life to the new Balancier Convexe S², one of the Atelier's iconic creations.
The new diameter of 41.5 mm has been specifically designed for carbon. It’s a radical change, immediately visible on the wrist. This timepiece is tighter, livelier, and even more modern. The very dark tone of the carbon reinforces the feeling of a very compact piece, while staying open to display the movement, complication and finishes.
From a technical perspective, the challenge was significant. To impose as complex a geometry on carbon as that of the Balancier Convexe S² convex case is an unprecedented move in watchmaking. It requires a precise combination of temperature and pressure. Heat makes the carbon more flexible to work with; pressure gives it its shape. A conventional case usually requires 2 tonnes of pressure per square centimetre. For Greubel Forsey's signature convex case, it was necessary to apply 16 tonnes: 8 times more than is conventional.
By multiplying the layers of carbon, each of which measures 1 to 5 microns, Greubel Forsey has obtained a much denser carbon case, revealing the perfect combination of technique and aesthetics so well known to the Atelier manufacture.
Each case is individually enhanced by the arrangement of its fibres, carefully controlled by Greubel Forsey to create the perfect profile. The direction of the carbon fibres is a top priority, so that they align with the curvature of the convex case, which is underlined by the hand finishing.
Convex on the case back as well as the display side, the timepiece hugs the wrist perfectly. At 12 and 6 o'clock, the two converging lines give the Balancier Convexe S² a 3D geometry of unequalled complexity. It delivers an unprecedented volume, giving way to a vast open space under the sapphire crystal at 6 o'clock. Within, the 30° Inclined Balance Wheel that has been completely redesigned to fit the new proportions of the carbon case, has plenty of space.
The 303-part movement delivering a 72-hour chronometric power reserve has a perfectly 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 now features a black treatment in keeping with the case and carbon plate. Finally, the relief engraving on the 3D barrel cover blends seamlessly into the redesigned case.
Balancier Convexe S²
Manual winding movement, hours and minutes, small seconds, power reserve, 30˚ inclined Greubel Forsey balance wheel systemDownload the data sheet
- Case material Carbon
- Limitation 22 pieces (2023-2026)
- Chronometric power reserve 72 hours
- Case diameter 41.5 mm
- Water resistance 5 ATM - 50 m - 164 ft
- Number of parts 303
- Frequency 21,600 vibrations/hour
- Height (incl. crystal) 14.8 mm