Grand Seiko Debuts the Kodo Constant-force Tourbillon

Grand Seiko Debuts the Kodo Constant-force Tourbillon

In 2020, Grand Seiko raised eyebrows and the occasional heart rate with their announcement of the T0 Constant-force Tourbillon, a complicated concept that is now a reality. Comprising 340 components, caliber 9ST1 is a mechanical achievement that sees the constant force mechanism integrated into the tourbillon cage, an ingenious solution that delivers numerous benefits. Because they are on the same axis, there’s no loss of torque between the two, allowing for 50 hours’ duration for the constant force mechanism (with 72 hours of power reserve), and stable amplitude of the balance resulting in greater accuracy — something proved during the 34-day testing process the caliber goes through.

A side view of the Grand Seiko T0 (T-Zero) Constant-Force Tourbillon
A side view of the Grand Seiko T0 (T-Zero) Constant-Force Tourbillon

Technique is only part of the picture, though. Grand Seiko is famous for their particular aesthetic and style, and this new mechanism fits the bill. Though the open-worked design is a look we don’t associate with the brand, the design of the movement had to be wearable, and indeed it is. The reference SLGT003 is housed in a platinum and Brilliant Hard Titanium case rated to 100 meters. At the same time, the mechanism is finished to Grand Seiko’s famously high standards while also allowing enough air and light into the movement, highlighting the harmony and the craft. This watch will be limited to 20 pieces, with an approximate retail price of €370,000.

While the watch itself is an incredible achievement, it’s what it represents for Grand Seiko’s future that’s truly exciting. This watch is the product of a new design team and studio, the Atelier Ginza, based in the heart of Tokyo, where Kintaro Hattori founded Seiko in 1881. This metropolitan watchmaker looks set to create some of the world’s finest watches in the years to come, and we can’t wait.

Tech Specs

Kodo Constant-force Tourbillon

Movement: Manual-winding caliber 9ST1 with constant-force tourbillon; 72 hours of power reserve, 50 hours on the constant force mechanism
Functions: Hours, minutes, small seconds (on tourbillon cage), constant force mechanism
Case: 43.8mm x 12.9mm; Platinum 950 and Brilliant Hard Titanium; water-resistant to 100m
Strap: Calf strap with Platinum 950 three-fold clasp with push-button release; double-sided crocodile strap included
Availability: October 2022; limited to 20 pieces.

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Felix Scholz

Felix Scholz has spent the last decade covering watches from his home in Australia. Given this, it's surprising that he still struggles with time zones. Over the years he's become a firm believer that less is more when it comes to watch design – except when a rainbow bezel is involved. He's written for numerous titles including Hodinkee, GQ, A Collected Man and more. These days he looks after the Australian edition of Revolution and takes a break from writing about watches to talk about them, as the co-host of OT: The Podcast.

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