Kronos Germany reviews the Tudor Black Bay GMT

The Tudor Black Bay GMT is a mid-range GMT watch equipped with an in-house movement. It features a user-friendly GMT mechanism that allows for independent adjustment of the hour hand, a free-sprung spring, and a silicon balance spring, making it highly accurate. Martina Richter of Chronos Germany tested the watch.

Tudor Black Bay GMT

Founded in 1946 by Hans Wilsdorf

　Today, traveling and working around the world is commonplace, even for those outside of pilots and jet-setters. GMT watches, which allow the wearer to check a second time zone, are a feature that fits the modern, increasingly globalized world. Rolex founder Hans Wilsdorf founded Montre Tudor SA in 1946, offering high-quality timepieces at more affordable prices than Rolex.

　Until 2015, Tudor relied on ébauches for its movements, but our test Black Bay GMT is equipped with the in-house movement Caliber MT5652 while maintaining an appealing price point. This movement is Tudor's second in-house caliber with an added complication, following the Caliber MT5813 chronograph movement developed in collaboration with Breitling and featured in the Black Bay Chrono.

The time display works in several ways

　Pulling the crown out to the middle position and turning it makes it clear that this is not simply a GMT module added to an existing movement. In other words, the hour hand can be adjusted independently, and the date display is linked to fast-forwarding or fast-backwarding the hour hand.

　All of this is done without stopping the balance, so accurate time is always maintained. Currently, there are only a limited number of models with a GMT hand that allow the hour hand to be adjusted independently, rather than the GMT hand.

　The time zone function can be used in several ways. The most common method is to align the red sub-hour hand, which rotates once every 24 hours, with the local time (i.e., the time set by the hour hand) to indicate day and night. In other words, local time is the same as home time.

　If you want to indicate a different time zone without adjusting the time, simply rotate the bidirectional rotating bezel and the 24-hour hand will indicate the second time zone. The 48 notches on the rotating ring also allow you to display adjacent time zones in 30-minute increments, such as India, Myanmar, or South Australia.

　However, when traveling to a different time zone, it may be more practical to set the hour hand to the local time rather than leaving the secondary hour hand to indicate the home time, since it's easy to set a new local time on the Black Bay GMT while traveling.

　To do this, simply pull the crown out to the middle position and rotate it. As mentioned above, the main hour hand moves forward or backward in one-hour increments, but the movement does not stop. This means that when you return home at the end of your trip, you only need to readjust the hour hand forward or backward.

　The large, knurled crown is borrowed from a Tudor diver's watch and is extremely easy to operate: it screws into a long tube, but it slides out smoothly, clicks securely into each position, and has a slight spring-loaded feel when you push it in.

High visibility day and night

The stylish rose-embellished crown is reminiscent of a logo that Tudor used in the past. Since 1969, Tudor has featured a shield on the dial, as does our test watch. This was inspired by diving watches made in the 50s.

　The clear applied indices—eight circles, a rectangle at 6 and 9 o'clock, and a triangle at 12 o'clock—pop out against the black dial, creating a strong contrast with the luminous "snowflake" hands, optimizing legibility day and night.

　Snowflake hands are an unmistakable Tudor signature, first appearing in 1969. This watch features three snowflake hands, and they're virtually unmistakable: the thickest is the hour hand, the constantly moving second hand, and the third, red hand that completes one revolution every 24 hours is the secondary hour hand.

　The bidirectional rotating bezel features a navy blue and burgundy red aluminum inlay and features the typical Black Bay bezel fluting on the sides.

　The case is 41mm in diameter and made of stainless steel, and is water resistant to 200m. It has the same features as a diver's watch, such as a folding clasp with an extension mechanism and a safety mechanism, but as is clear from the bidirectional rotating bezel with a 24-hour scale, it is not marketed as a diver's watch.

　The handsome case, like many other details of the Black Bay GMT, is paired with a riveted bracelet reminiscent of Tudor's watches from the 50s and 60s, when the rivet heads connecting the various components were visible through the links. The Black Bay GMT's steel bracelet tapers from 22mm at the case to 18mm at the clasp.

　In addition to the bracelet, the watch is also available in a brown leather strap called "Terra di Siena," as well as a textile strap, made by a family-run French company with a 150-year history of traditional jacquard weaving.

High-precision and long-power reserve movement

　The Black Bay GMT's case back is solid and sturdy. While its robustness is impressive, it unfortunately conceals the new in-house caliber MT5652. This movement follows in the footsteps of its predecessor, which was designed with robustness, durability, and reliability in mind, and features a skeletonized rotor and a simple baseplate and bridges.

　The large balance wheel is free-sprung, with a mass slotted adjustment mechanism rather than a regulator. This large balance wheel, along with the anti-magnetic silicon balance spring, is what enables the Caliber MT5652 to achieve high accuracy. The Black Bay GMT's daily deviation is within +1 second when worn fully wound, and remains within +3 to +4 seconds even after 42 hours without additional winding.

　With a power reserve of approximately 70 hours, even if you leave it alone over the weekend, you won't need to wind it or set the time on Monday morning.The comparable GMT movement, the Caliber ETA 2893-2, is used in many GMT models, but its power reserve is only about 42 hours.

　The Tudor Black Bay GMT is a high-quality watch with a new in-house movement that combines legibility, value, ease of use, and wearability. There are few comparable models in this price range.

Technical specifications

Accuracy stability test (daily rate of seconds/day and swing angle immediately after winding and T24)

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