Double Balancier Convexe

Greubel Forsey delivers a new generation of carbon timepieces. The material becomes part of the Atelier's collections, offering collectors enhanced lightness and resistance.

Recognised and appreciated by collectors, the Convexe case fully benefits from this design choice. On the case back, its form perfectly meets the curve of the wrist. On the dial, a three-dimensional, curved profile allows the movement to fully express itself. Since carbon fibres are never combined twice in the same way, the design of each piece will also be unique, reinforcing the exclusivity of the timepiece.

It was no mean feat to produce the Convexe carbon case. The carbon case, as developed by Greubel Forsey, requires pressure 8 times greater than average (16 tonnes applied to a Convexe case, compared to an industry standard 2 tonnes). This mechanical effort makes it possible to obtain a much denser carbon for an almost identical weight, to be enjoyed by the collector.

For Greubel Forsey, this specific technique opens up the possibility of executing fine watchmaking finishing by hand that affirm the Atelier’s identity and status. This is how you'll come to find finishes, from satin to matt and relief engraving on the Double Balancier Convexe, all complementing the natural work of the carbon fibres that Greubel Forsey has taken care to match with the converging lines on the Convexe case. This is carbon deployed at its best, both flexible and solid, with fibres between 1 and 5 microns thick, perfectly defined and mastered.

A truly unique expression of this sixth Fundamental Invention, while the invention itself has never stopped evolving. Its prototype mechanism was patented in 2007. It was first proposed as part of an EWT (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 and meets the performance, precision and reliability requirements that Greubel Forsey sets for all its timepieces.