With the introduction of the final two editions of the Balancier Convexe S2, Greubel Forsey continues its exploration of form and chronometry through one of its most recognisable platforms.
Presented in black ceramic combined with 5N red gold, and in white ceramic, these two executions build on a calibre introduced in 2021 (read about it here), each issued in a limited run of 11 pieces.
The Balancier Convexe S2 was conceived as a fully integrated object, where the case is not a simple container but an extension of the movement itself.
Its case, measuring 41.5 mm across the caseband with a bezel diameter of 44 mm, follows the natural curvature of the wrist, reaching a height of 12.85 mm in the white ceramic version and 13.25 mm in the black ceramic and red gold model (14.8 mm including the domed sapphire crystals).
The curved sapphire crystals on both sides reinforce the continuity between exterior form and mechanical construction, which naturally leads into the movement.
At its centre is the 30° inclined balance wheel syste, positioned as both a visual focal point and a regulating organ. The hand-wound calibre measures 37 mm in diameter and 10.05 mm in thickness and is composed of 301 components, including a 68-part escapement platform set at an angle to enhance chronometric stability across positions.
The architecture is deliberately open, with multi-level, suspended bridges revealing the functional elements rather than concealing them.
Energy is supplied by two fast-rotating coaxial barrels coupled in series, completing one rotation every 3.2 hours and delivering a chronometric power reserve of 72 hours.
One of the barrels incorporates a slipping spring to prevent excessive tension. The in-house variable-inertia balance, measuring 12.6 mm in diameter and fitted with six gold mean-time screws, operates at a frequency of 3 Hz (21,600 vibrations per hour) and is paired with a balance spring featuring a Phillips terminal curve and Geneva-style stud.
Execution remains consistent with the brand’s standards. Titanium bridges and main plates are frosted and finished by hand, with polished bevels, countersinks and carefully controlled transitions between surfaces.
This level of attention extends throughout the movement, including areas that are not immediately visible, reflecting a coherent approach to construction.
The two editions differ in their visual expression while sharing the same mechanical base.
The black ceramic and 5N red gold version emphasises contrast, with dark-treated movement components framed by the ceramic case and complemented by the warmth of red gold elements on the bezel, caseback and crown.
The white ceramic model takes a more restrained direction, where the monochromatic case highlights the openness of the movement and allows its structure to emerge through light and shadow.
Both retain the same functional layout, with hours and minutes displayed on a suspended arch bridge, small seconds on a dedicated subdial and a sector-shaped power-reserve indicator.
The three-dimensional hour ring, applied indexes with Super-LumiNova and curved steel hands contribute to legibility, while reinforcing the layered construction of the dial side.
Water-resistant to 3 ATM (30 metres 7 100 feet), the case is paired with an integrated rubber strap secured by a folding clasp in titanium or a combination of titanium and 5N red gold, depending on the version.
Details such as the engraved case inscriptions and the titanium crown with interchangeable rubber capping complete the overall execution.
Each edition of the Greubel Forsey Balancier Convexe S2 is priced at CHF 295,000 before taxes. greubelforsey.com
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