Watch Of The Week: The Grand Seiko Kodo Constant-Force Tourbillon

Grand Seiko arrived in Geneva this year with major news: the brand would be revealing its first mechanical complication in its history. Perhaps one of the buzziest timepieces of Watches & Wonders, the new Grand Seiko watch completely stole the show. 

For the first time in horological history, the Grand Seiko Kodo Constant-Force Tourbillon combines a constant-force mechanism and a tourbillon as one unit on a single axis, creating a new rhythmic heartbeat. Kodo, which translates to the heartbeat in Japanese, is symbolic of the motion of the new mechanism because the innovative movement that delivers a level of stable accuracy unprecedented for Grand Seiko lives in the heart of the watch.

Photo Credit: Alex Teuscher

The Kodo is a true testament to the unparalleled craftsmanship of Grand Seiko as the creation, from the inception of the project to the final manifestation, took a decade to perfect.

Each of the 340 components of the caliber was meticulously re-examined, re-designed, and re-engineered for production, resulting in Caliber 9ST1—setting a new standard of accuracy, in which each movement is tested for a total of 48 hours in each of six positions and at three temperatures.

There’s no denying the groundbreaking integration of the two mechanisms creates a stunning visual effect. The inner tourbillon carriage rotates smoothly as the balance steadily vibrates at 8-beats per second, and the outer constant-force carriage follows its rotation at exact one-second intervals. The watch remains loyal to the design DNA for which Grand Seiko is known, which is realized in every functional detail. The constant-force carriage has a ruby on one of its arms, which acts as a small seconds hand, and the hour hand has an extra facet at its tip to enhance its readability.

Photo Credit: Alex Teuscher

The case is constructed from Platinum 950 and Grand Seiko’s Brilliant Hard Titanium to achieve optimal, lasting luster. Some case parts of both materials are Zaratsu polished, and others have a hairline finish; both processes are completed by hand by highly skilled craftsmen and women to ensure that, from every angle, a visually pleasing harmony is seen. The case back is made with sapphire crystal, revealing the movement’s finishing and intricate construction.

Photo Credit: Alex Teuscher

The timepiece is designed with an extremely durable calf strap hand-painted with Urushi lacquer in a multi-coating process that gives the strap a delicate sheen. Alternatively, the timepiece is offered with a crocodile strap. 

The Grand Seiko Kodo will be available as a limited edition of twenty in October 2022, and the approximate recommended retail price is $350,000.

Photo Credit: Courtesy of Grand Seiko