Grand Seiko Sport Quartz GMT black dial steel bracelet 39 mm

Sport and GMT: a perfect match

The GMT function is an integral part of the Manufacture Grand Seiko's catalogue and is offered in a wide range of styles, either with a Spring Drive calibre or an Automatic movement. This time, the Japanese brand presents a watch from the Sport collection offering a quartz movement with GMT complication. A model designed to be a must-have for any frequent traveller!

Un design sport-chic

This SBGN027 has a steel case measuring 39 mm in diameter and 12.3 mm thick. It is associated with a brushed "oyster" type bracelet. The case is water-resistant to 100 metres and has a screw-down crown at four o'clock for optimum comfort, as well as a curved anti-reflective sapphire crystal surrounded by a fixed steel bezel with a 24-hour scale.

Its case has a good sense of balance and perfect proportions! Its exceptional finishes are eye-catching, with Zaratsu-polished surfaces contrasting with hand-satinned surfaces, underlining the Grammar of Design, the design philosophy of Grand Seiko.

We find on this reference a black sunray dial which presents monochrome reflections. The white GMT hand contrasts perfectly with this black dial. Precisely, the hands and the indexes of this model are nicely finished and have a Lumibrite painting for an excellent visibility at night. The hands have a brushed finish to contrast with the darker surfaces of the dial, which helps to improve legibility.

A Manufacture quartz calibre

When the 9F series was created in 1993, Grand Seiko engineers wanted to include a GMT function. Unfortunately, production limitations at the time did not allow for the production of the small leaf spring required for the independent hour hand adjustment function. Because of this difficulty, the idea was shelved until the problem was solved. In 2018, Grand Seiko finally introduced the calibre 9F86, the brand's first quartz movement to feature a GMT complication.

This calibre 9F86 has a precision of +/-10 seconds per year. It has a high torque, close to that of a mechanical movement, while maintaining a low level of energy consumption. An aged quartz crystal is combined with a very low power consumption integrated circuit, programmed according to the specific reaction of this crystal to temperature changes, thus guaranteeing the highest possible level of performance. Incidentally, each quartz crystal has different performance characteristics, but only the most accurate are selected for the Grand Seiko 9F movements. Grown in-house, they are aged and rigorously tested over a period of 3 months, to ensure that only the best quartz oscillators are incorporated into each timepiece.

The 9F86 is built to the same exacting standards as Grand Seiko's mechanical and Spring Drive movements, and features an almost all-metal construction. They are designed to be serviced by a qualified watchmaker.