Greubel Forsey’s watches are generally about addressing every line of inquiry in watchmaking with equal completeness, be it finishing or movement design and architecture or chronometry. It is the pursuit of not one, but all three, without regard to expense, that distinguishes a Greubel Forsey from every watch on the market, making each incarnation not only visually engaging, but also intellectually stimulating and emotionally rewarding. Since its inception, the company has been best known for the way it re-engineered the tourbillon so as to become a genuine aid in rate stability in a wristwatch. But equally emblematic is its execution of a GMT function, first introduced in 2011.
Up until then, multi-time-zone watches were executed in three predominant forms — an additional 12-hour hand, a 24-hour GMT hand, or a Louis Cottier-type world-time system. But the Greubel Forsey GMT provided an unusually poetic interpretation of a highly utilitarian complication, combining a GMT function and a world-timer, along with an actual three-dimensional model of the Earth. Fashioned from titanium, the globe makes one complete rotation every 24 hours anticlockwise — the Earth’s natural rotational direction — in addition to a 12-hour second-time-zone subdial and a cities disk on the back of the watch. The position of the continents on the globe as seen from the north pole can be neatly cross-referenced with the 24-hour equatorial chapter ring that doubles as a day and night indicator.
Last year, Greubel Forsey announced the conclusion of its very first GMT watch after a decade of production. By then, a sleeker, sportier and more practical incarnation of the watch had joined the lineup — the GMT Sport — bringing greater wearability with its convex water-resistant titanium case. While its movement had to be constructed from the ground up to accommodate the curvature of the case, the GMT Sport was functionally identical to its predecessor and is among the most complex watches produced by the brand, combining a visually spectacular world-time display with an inclined tourbillon. But this year Greubel Forsey has, for the first time, introduced a GMT-only version in the form of the GMT Balancier Convexe, where the magnificently large rotating globe takes center stage on the watch.
The World in Focus
In contrast to past GMT models where numerous elements — home time, local time, world time and tourbillon — vie for attention on an asymmetrical dial, the GMT Balancier Convexe adopts a much neater format with both local and world time presented in a concentric configuration, enabling them to be read with greater ease. Home time is read off a small 12-hour subdial, while local time is indicated with a pair of red arrows on a large subdial that spans three-quarters of the watch face. Nestled at the center of it is the beautiful titanium globe that is secured at just one end of its rotational axis — the South Pole — with the continents engraved in relief. It is encircled by a 24-hour chapter ring that has been blackened on one half to distinguish night from day.
By cross-referencing the geographic outlay of the globe with the 24-hour chapter ring, world time can be intuitively interpretated. But for greater precision, a simple yet ingenious world-time mechanism, which works in conjunction with the miniature globe, is displayed on the back of the watch. Not only does it show the correct time in 24 different time zones, but it also displays the time in cities that observe Daylight Saving Time (DST). Made of sapphire, the world-time disk has been engraved with the names of 24 cities, each representing a different time zone. It sits between a 24-hour outer ring that displays the local time in 24 time zones and an inner 24-hour hour ring that is displaced by one hour to indicate the time in cities that observe DST. Further, the cities that observe DST are distinguished by having their engraved names filled with black lacquer on the sapphire disk. Presently, this is the only world-time mechanism that offers an overview of all cities that observe DST as well as their actual numerical time in the summer, enabling time to be read as such: when it is 9pm in London in winter, it is 10pm in London in the summer. In contrast, most travel watches with a DST function do not display the actual DST digitally.
All these indications distributed on the front and back of the watch make the Greubel Forsey GMT Balancier Convexe one of the most comprehensive, intuitive and, not to mention, visually spectacular world-time watches on the market. And it doesn’t stop there. At seven o’clock on the dial is the brand’s signature inclined balance wheel. The purpose of mounting the balance at a 30° tilt from the vertical plane is to limit errors in rate caused by gravity in both the horizontal and vertical positions. Additionally, it also adopts traditional approaches to rate stability, such as having a free-sprung balance as well as a hairspring with a Phillips overcoil to ensure better concentricity. The balance has six gold inertial screws that have been inset into its rim to reduce air friction.
By eliminating the tourbillon and condensing the GMT and world-time displays, it not only makes for a usefully tighter, more practical proposition, but it also enables the brand’s impressive hand-finishing to come into focus. The brand’s core tenets are intricately engraved in relief around the 24-hour ring. The upper half of the dial features frosted finish applied for the first time on titanium in a Greubel Forsey watch. It contrasts nicely with the fine, frosted finish on the bottom half of the dial. The balance is held in place by a beautifully domed, black-polished bridge that is mounted on fully polished steel pillars. Additionally, the interior of the case is mirror polished to enhance the staggering depth of the dial elements.
Apart from a tiny extension wheel, which drives the small seconds display at five o’clock, the mainspring barrels and gear train are entirely hidden. Like most of Greubel Forsey’s movements, it is equipped with twin fast-rotating barrels to deliver a power reserve of 72 hours. Notably, the second barrel has a slipping bridle, which is a feature usually found in self-winding movements. The slipping bridle holds the outermost coil of the mainspring by friction to the barrel wall. Once the tension gets too high, the bridle slips, relieving excess pressure from overwinding.
The Ultimate Travel Watch
All these fireworks take place within Greubel Forsey’s ergonomic convex case, which marked a new era for the brand when it first debuted in the GMT Sport in 2019.
Superbly constructed, the tonneau-shaped case has a pronounced curvature, enabling it to sit comfortably on the wrist. The oval bezel is curved vertically from 12 to six o’clock such that it appears perfectly round from above. To accommodate the curvature of the case, the crystal is also curved, which further emphasizes the immense depth of the dial. Most notably, the circumference of the bezel extends slightly outward from the case toward the integrated strap, allowing the watch to appear a lot larger than it wears — 46.5mm wide at its bezel with a base diameter of just 43.5mm. Due to the nature of the movement, the case is necessarily thick with a height of 13.75mm excluding the crystal; but with its clever design, which reduces the perceived size of the watch along with its exemplary finishing, it still manages to be rather elegant as far as sports watches go.
The lugs, which are secured to the case with visible screws, have a brushed upper surface with chamfered edges, while the bezel is brushed at its top surface with a wide, polished outer bevel. At 10 o’clock on the case is a pusher marked “GMT”, which advances the 12-hour subdial by one-hour increments. Thus, for convenience when zipping through different time zones, the 12-hour dial can be used instead to indicate local time.
While many other multi-time-zone watches can be had with the same amount of money, there are few that bring poetry and dimensionality to the way we perceive and capture universal time like the Greubel Forsey GMT Balancier Convexe, and even fewer that offer the same attention to detail or level of finishing. The combination of these attributes, underpinned by the pursuit of better chronometry, puts any Greubel Forsey GMT in a class of its own. But with an ergonomic, water-resistant titanium case and a streamlined dial, the GMT Balancier Convexe becomes that much more viable as an actual travel companion.