Greubel Forsey Reimagine Global Time With The GMT Balancier Convexe
Greubel Forsey continues to challenge conventional ideas of mechanical watchmaking with the GMT Balancier Convexe, an extraordinary expression of contemporary horology that places global timekeeping, sculptural design and mechanical ingenuity at the heart of the watch.
The GMT Balancier Convexe brings together the Atelier’s signature 30° inclined balance wheel system with one of its most recognisable creations, the rotating terrestrial globe. Encased in titanium and shaped around the natural curvature of the wrist, the result is a highly architectural timepiece in which every element appears to have been conceived as part of a single three-dimensional composition.
At the centre of the dial sits a miniature Earth, crafted in titanium with relief-engraved continents and an ocean-blue treatment. Rotating once every 24 hours, the globe provides an immediate visual representation of universal time while reinforcing Greubel Forsey’s fascination with the relationship between horology and the measurement of time across the world.
Surrounding the globe is an amphitheatre of indications. Hours and minutes are displayed alongside a second time zone, while a dedicated day-and-night indicator provides an intuitive indication of the passage of time around the globe. Universal time is represented across 24 time zones, with separate indications for summer and winter time and the cities observing seasonal changes.
The GMT function is operated through a dedicated pusher, allowing the second time zone to be adjusted while retaining the clarity of the principal display.
Yet the GMT Balancier Convexe is about considerably more than its complications. Beneath the architecture lies a sophisticated hand-wound movement comprising 496 components and 72 jewels. Its two series-coupled fast-rotating barrels provide a chronometric power reserve of 72 hours, with one barrel incorporating a slipping spring designed to prevent excess tension.
At the heart of the calibre is Greubel Forsey’s in-house variable-inertia balance wheel, fitted with six gold mean-time screws and measuring 12.60mm in diameter. Oscillating at 21,600 vibrations per hour, it is paired with a Phillips terminal curve and Geneva-style stud.
The regulator is positioned at the Atelier’s characteristic 30° inclination. Suspended within the escapement platform, the balance wheel becomes a major visual element of the watch rather than something hidden beneath the dial. Its flat black polished steel bridge, supported by polished steel pillars, creates a dramatic contrast with the surrounding architecture.
The movement itself continues Greubel Forsey’s uncompromising approach to finishing. The bridges and main plates combine titanium and nickel-silver, with frosted surfaces, polished bevelling and countersinks and straight-grained flanks. The power-reserve and small seconds bridges receive a blue treatment, while the inclined escapement platform combines flat black polishing with polished bevelling and carefully straight-grained flanks.
The technical architecture extends into the gearing, which employs an involute circle profile together with an inclined fourth wheel featuring profiled teeth.
Greubel Forsey has developed the exterior with the same attention to three-dimensional form. The titanium case measures 42.90mm across the caseband and 44.90mm across the bezel, with a height of 15.10mm. Its curved sapphire crystal and high-domed sapphire caseback emphasise the convex character of the construction, while the three-dimensional variable-geometry bezel is hand-polished and hand-finished with straight graining.
Profiled lugs and titanium security screws reinforce the technical character of the case, while raised GMT and Greubel Forsey engravings provide the finishing signatures. An engraved GMT pusher is integrated into the case, while the titanium crown incorporates interchangeable colour-coded rubber capping and the GF logo.
Turn the watch over and the global theme continues. A sapphire disc displays the names of the 24 reference cities, surrounded by two engraved and lacquered rings representing UTC and summer time. A gold summer-time plate carries the limitation number and is hand matt lapped, providing another example of the extraordinary attention given to even the smallest components.
The GMT Balancier Convexe is completed by hand-sewn textured rubber or rubber with text in relief, secured by a titanium folding clasp engraved with the GF logo. A three-row titanium bracelet with integrated fine adjustment is also available on demand.
With its rotating Earth, 24 time zones, second time zone, day-and-night indication and spectacular 30° inclined balance wheel, the GMT Balancier Convexe demonstrates Greubel Forsey’s distinctive ability to turn complex mechanical information into an object of extraordinary visual depth.
This is global timekeeping reimagined through the lens of contemporary Fine Watchmaking, where the Earth becomes the centre of the dial and the movement becomes an architectural sculpture in its own right.
Technical Specifications
GMT Balancier Convexe
Titanium
Limited edition
Patented hand-wound movement
GMT, second time zone, rotating globe with universal time and day-and-night indication, universal time across 24 time zones, summer and winter time, cities observing summer time, GMT pusher, 30° inclined Greubel Forsey balance wheel system, hours and minutes, small seconds and 72-hour power reserve.
Movement
Overall diameter 37.80mm
Thickness 13.80mm
496 movement components
59 escapement platform components
72 jewels
72-hour chronometric power reserve
Two series-coupled fast-rotating barrels
In-house variable-inertia balance with six gold mean-time screws
21,600 vibrations per hour
Case
Titanium with curved sapphire crystal
42.90mm caseband diameter
44.90mm bezel diameter
15.10mm case height
17.60mm height including sapphire crystals
Water resistance 5 ATM / 50 metres
Displays
Hours and minutes
Small seconds
Second time zone GMT
Rotating terrestrial globe
Universal time
Day-and-night indication
24 time zones
Summer and winter time
72-hour power reserve
Price on application
For more information please visit Greubel Forsey.