Limited Edition of 11 Pieces
Augmented ergonomics, Assertive profile
Already in 2015, the GMT Black paved the way for the GMT Sport. Building on this foundation, Robert Greubel and Stephen Forsey have invented and now present the result, a lightweight and ultra-strong, profiled titanium case with ovoid bezel and integrated lugs to showcase the new movement. Water resistant to 100 meters, the new GMT Sport stands out as their most sport oriented timepiece to date.
The movement was constructed from scratch from the suspended arched bridge for the hours and minutes display, to the unique showcase of the Tourbillon 24 Secondes and the universal time display with three dimensional globe. Another truly assertive Greubel Forsey and a revolution: the successful alliance between ergonomics, technicity and architecture.
Strong and truly original case geometry
The completely new and original titanium case, firmly positions this new GMT in a “sports” league of its own. In their creation of this timepiece, Robert Greubel and Stephen Forsey have pushed back the limits of ergonomics and wrist comfort. They have invented a totally new case form, perfectly round from above, while revealing the accentuated arched and ovoid shape from other angles. The aerodynamics of this timepiece 4 patents are reinforced by its integrated lugs and strap resulting in distinct functional forms that perfectly fit any wrist. The sweeping satin finished bezel with Greubel Forsey’s values relief engraved on its outer bevel, follows this unique case shape. The curved profile of the 45mm diameter case and ovoid sapphire crystal provide the perfect showcase for an entirely new movement architecture with an arched bridge and inclined gear train.
The Tourbillon 24 Secondes, the source of exceptional precision
The 24 Seconds Tourbillon is showcased at 1 o’clock secured by its distinctive and highly polished tourbillon bridge with black finished openings. This third Fundamental Invention by Greubel Forsey in the field of the tourbillon (after the Double Tourbillon 30 ° and the Quadruple Tourbillon) stands out with its cage inclined at 25 degree completing one full rotation in 24 seconds. The faster speed combined with the inventive cage inclination, significantly improves chronometric performance in a single-tourbillon system, with minimal movement height. This exclusive and patented configuration counters the disturbances induced on the movement by earth’s gravity, especially in stable positions. The rotating tourbillon cage housing the regulating organ has 88 components, for a weight of 0.38 grams a feat made possible in particular by light alloy pillars and titanium bridges.
A terrestrial globe showing universal time
Precision and reliability summarise Greubel Forsey’s ground-breaking GMT mechanism, presented for the first time in 2011, with the GMT Black presented in 2015. In this double-patented mechanism, the second time zone indication on the auxiliary dial between 10 and 11 o’clock is combined with a universal time display to intuitively read the current time anywhere in the world. The remarkable innovation and striking spectacle of the terrestrial rotating globe seen from above the North Pole performs each complete anticlockwise turn on its axis in 24 hours. It’s surrounded by a sapphire crystal ring with 24-hour divisions; where the wearer can read local time for all longitudes, including the day / night indicator (light zone / dark zone). On the caseback side of the GMT Sport, outer and central rings complete the sapphire cities disc to give UTC Universal and Summer Time for 24 cities in major timezones. This disc distinguishes those time zones applying summer time (on a light background) from those that do not (on a dark background). Reviewing the ergonomics, the GMT’s functions use two pushers located on the left side of the case; one to select the second timezone and the other for synchronising the local time with the globe.
Technical Specifications:
The case, in titanium, measures 45mm x 15.7mm (17.8mm with the domed sapphire crystal). It is water resistant to 100 meters. Curved double sapphire crystals. Three-dimensional, variable geometry-shaped bezel with raised engraved text. Profiled lugs, screwed fixing. Engraved pushers. Rubber capped crown.
Movement is a Swiss manual-wind Greubel Forsey in-house caliber (three patents pending) with 63 jewels, 21,600 vph and a power reserve of 3 days. Olived-domed jewels in gold chatons.
It features wwo 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. Variable-inertia balance wheel with gold mean-time screws. Phillips terminal curve balance spring. Geneva-style stud. The bridges and main plate are done in titanium, frosted and spotted, with polished bevelling and countersinks, straight-grained flanks, black treatment. Multi-level, suspended-arch bridge, polished with black treatment in relief, polished bevelling and countersinks, straight-grained flanks. Flat black polished tourbillon bridge with black treatment in relief, spotted, polished bevelling and countersinks, straight-grained flanks. Tourbillon: Inclined at a 25° angle, 24-seconds rotation. Light alloy cage pillars with titanium cage bridges and gold counterweight. Involute circle profile gearing. Tangential inclined gear on fixed wheel and on escape wheel pinion. Inclined gear and profiled teeth on intermediate wheels of the set-hands mechanism.
Functions are: hours and minutes, on suspended-arch bridge. Small seconds on disc. Power reserve on a sector. 24-seconds tourbillon rotation. Rotating titanium globe with universal time, day-and-night, and second timezone GMT. 24 timezones universal time and Summer time.
The dial has a three-dimensional, variable geometry hour-ring, with luminescent hours and minutes indeces. GMT indicator with raised engraving. Power-reserve indicator, engraved and lacquered. Tourbillon rotation indicator in gold. Rotating globe with fixed day-and-night UTC indicator in sapphire, engraved and lacquered. Synthetic sapphire disc displaying city names surrounded by 2 rings (UTC engraved on the case /Summer time engraved on a gold movement plate, lacquered and hand matt-lapped) in the caseback. Polished steel curved shape hours and minutes hands with SuperLuminova. Second timezone GMT indicator, red triangle. Small seconds, fixed red triangle. Power-reserve indicator, in polished steel. Aluminium 24-seconds double-tipped hand, black treatment.
It comes on a blur or black rubber strap with relief text and a titanium folding clasp.
