Greubel Forsey’s Balancier Convexe S2 has been redesigned in a more compact carbon case in two limited series of only 22 pieces (each), with the emphasis placed on the technical nature of carbon, the excellence of its finish and an unprecedented diameter of 41.5mm.
The new Balancier Convexe S2, one of the Atelier’s iconic creations, with its 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 convexe 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 convexe case, it was necessary to apply 16 tonnes: 8 times more than is conventional.
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 convexe case, which is underlined by the hand finishing. The crown asserts a bold matt finish. The engraving is of note: always in relief for the convexe case, and remaining so on this carbon case – with particular attention accorded to the precision of the “GF” initials, finishing flush with the centre of the crown.
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.
The new Balancier Convexe S2 will be produced in two limited editions of 22 pieces each, the small seconds with blue or black treatment, matching textured rubber strap, and a titanium and carbon buckle.
Technical Specifications:
Balancier Convexe S2
Carbon
Limited edition of 22
Hand-wound movement • Patents pending
Hours and minutes • small seconds • power-reserve • 30° inclined Greubel Forsey balance wheel system
Movement
Movement dimensions
• Overall diameter: 37.00 mm
• Thickness: 10.05 mm
Number of parts
• Movement: 303 parts
• Escapement platform: 68 parts
Number of jewels
• 43
• Olived-domed jewels in gold chatons
Chronometric power reserve
• 72 hours
Barrels
• Two coaxial series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
• Relief-engraved text, circular-grained, black treatment
Balance wheel
• In-house variable-inertia with 6 gold mean-time screws (12.60 mm diameter)
Frequency
• 21’600 vibrations/hour
Balance spring
• Phillips terminal curve
• Geneva-style stud
Bridges and main plates
• Carbon and titanium
• Frosted, polished bevelling and countersinks, black treatment
• Multi-level, openworked suspended-arch bridge, black treatment, straight-grained and polished, polished bevelling and countersinks
Movement side
• Frosted bridges, polished edges and bevelling
• Gold plate with engraved limitation number, circular-grained, polished bevelling and countersinks, straight-grained flanks
Escapement platform
• Titanium
• Inclined at a 30° angle
• Frosted, polished countersinks, large straight-grained inclined facet
• Multi-level, openworked balance wheel bridge, straight-grained and polished, polished bevelling and countersinks
Gearing
• Involute circle profile
• Inclined gear and profiled teeth on intermediate wheels of the set hands mechanism and small seconds
Displays
• Hours and minutes, on suspended arch bridge
• Small seconds
• Power reserve on a sector
Exterior
Case
• Carbon and titanium with curved synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped bezel, hand-finished
• Profiled lugs, screwed fixing
• Transparent back with high domed synthetic sapphire crystal
• Titanium security screws
• Raised engraving “Balancier Incliné” and “Greubel Forsey”
Case dimensions
• Caseband diameter: 41.50 mm
• Bezel diameter: 44.00 mm
• Case height: 12.85 mm
• Height on synthetic sapphire crystals: 14.80 mm
Water resistance of the case
• Water-resistant 5 atm – 50 m – 164 ft
(standard NIHS 92-20/SN ISO 22810:2010)
Crown
• Carbon, hand-finished with GF logo
Dial side
• Three-dimensional, variable geometry hour-ring, polished, with engraved and lacquered minute-circle
• Three-dimensional, variable geometry hour indexes, polished, with Super-Luminova
• Power-reserve indicator, engraved and lacquered
• Gold small seconds dial with polished bevel
Hands
• Hours and minutes, curved profile, polished steel with Super-Luminova
• Small seconds, in polished steel, flat black polished head
• Power-reserve, red triangle
Strap and clasp
• Non-animal material, rubber with texture in relief, titanium and carbon folding clasp, engraved GF logo
Price on request
For more information please visit Greubel Forsey