Greubel Forsey is closing the book on the Balancier Convexe S² with two final ceramic editions, one in white, the other in black, featuring a 5N red gold bezel and case back. Each is limited to 11 timepieces, making them the most exclusive executions the S² has seen. When production of the GF09XV calibre ceases later this year, these will stand as its last word. The final two editions of a calibre five years in the making, with production ending permanently in 2026.
Things to Know About the Watch
The Convexe case architecture, measuring 41.5 mm across the caseband and 14.80 mm at its tallest point on the sapphire crystals, was designed from the outset so that the case and movement would function as a single integrated object. The convex geometry follows the natural curvature of the wrist, and the three-dimensional bezel with profiled ceramic lugs extends the movement's architecture outward rather than simply enclosing it. Curved synthetic sapphire crystals on both sides reinforce that continuity.
The two editions take opposite aesthetic positions on the same mechanical foundation. The black ceramic and 5N red gold version plays with contrast and depth—black-treated movement components set against a warm gold bezel and caseback, with matte-to-polished surface transitions amplifying the three-dimensionality of the calibre.
The white ceramic edition goes monochromatic, using light and shadow to reveal the movement's structure in a more graphic, technically transparent expression. Both retain the same functional layout: hours and minutes displayed on a suspended arch bridge, small seconds on a gold sub-dial, and a sector power-reserve indicator with a red triangle hand.
The bezel diameter is 44.00 mm, the caseband 41.5 mm, and the case height is 12.85 mm. Water resistance is rated to 30 meters. The crown is titanium and rubber with interchangeable colour-coded capping. Straps are hand-sewn textured rubber with a titanium folding clasp.
The Movement
The hand-wound GF09XV calibre is built around Greubel Forsey's patented 30° inclined balance wheel system, positioned as both the visual and chronometric centre of the composition. The movement totals 301 components, with 68 dedicated to the escapement platform alone, and carries 43 jewels in olived-domed gold chatons. Two coaxial series-coupled fast-rotating barrels—completing one turn every 3.2 hours—deliver a 72-hour power reserve.
The in-house variable-inertia balance wheel—12.60 mm diameter—with six gold mean-time screws operates at 3 Hz. Bridges and main plates are titanium, frosted and hand-finished with polished bevelling and countersinks. The multi-level open-worked suspended-arch bridge is straight-grained and polished. Every component, including those largely hidden from view, receives the same level of finishing, a Greubel Forsey hallmark that prioritizes integrity of construction over visibility.
Summary & Price
The Balancier Convexe S² was never a watch designed to evolve indefinitely. These two ceramic editions — 22 pieces total — are Greubel Forsey's deliberate farewell to a five-year calibre, and a signal that the maison is pivoting toward an almost entirely new collection. For collectors, the significance is straightforward: once these are allocated, the GF09XV movement is gone.
Sticker Price Upon Request. More info on Greubel Forsey, here.
