Two Years After Making History, The Grand Seiko Kodo Constant-Force Tourbillon Returns

April 09, 2024

Two years ago, Grand Seiko made its C well C grand entrance into Watches & Wonders. It made that entrance especially meaningful by debuting its first true mechanical complication via the Kodo Constant Force Tourbillon. This watch took the show by storm and I have vivid memories of the whole team rushing over to the GS booth just to get a glimpse of it. It took years of development, un-cased tourbillons, and Credor complications before the brand finally made real what many of us knew was coming in some fashion. In fact, if you want the entire backstory, read our hands-on coverage with the original Kodo from the 2022 show. Needless to say, the execution of the Kodo, in addition to the mechanical prowess blew everyone away. And the watch went on to win the Chronometry Prize at the GPHG. So now, two years later, Grand Seiko is unveiling another iteration of the Kodo. In essence, it is the same watch, but where the first one evoked the spirit of the night, this is one that is meant to represent daybreak and you can see that from the metal all the way to the strap. Before getting into the newness, it's important to understand just what this watch does on a fundamental level. Grand Seiko has always strived to make watches with particular attention to detail and an eye toward perfection, practicality, and problem-solving. We know the finishing techniques, we know the dial work, we know Spring Drive. At the time the Kodo was announced in 2022, GS didn't yet have a mechanical chronograph. That changed last year with the Tentagraph. But the Kodo brought a remontoire constant force mechanism into play. What this is, is an intermediate power source between the mainspring and the escapement and solves the issue of a watch speeding up as the mainspring winds down. It does so by making sure not to pass too much or too little power early or late in a watch's power reserve. It delivers a constant stream of power to the escapement so long as there is enough power in the mainspring to wind the remontoire. This, combined with the tourbillon, makes it so that both energy and positional variance are accounted for. Problem solved. But of course, Grand Seiko solved said problem in 2022. So today's announcement is simply bringing more to the Kodo line with the new SLGT005. The case is made from platinum 950 (inner case) and hard titanium (outer case) and the movement is silver-toned, unlike the darker original model which, as mentioned, gives it the feeling of brightness. Each component, as expected, is hand-polished. For the first time ever on a Grand Seiko, blue sapphires are used for the jewels to represent dawn. The movement consists of about 340 components C 140 of which are utilized for the constant-force and tourbillon carriages. Another visual difference with this watch from the original Kodo is the white strap, which is exclusive to this model. It is a white leather created from a highly durable material and treated in the traditional methods once used for Samurai armor. Of course, it goes deeper than that as the specific white color used for this strap was specifically created for the Kodo using white-urushi lacquer. In addition, the watch also comes with a charcoal grey strap. The Kodo is made at the atelier Ginza by a special team of watchmakers and there is an engraving on the caseback denoting that. This new Kodo is being released as a limited edition of 20 and will be available in December 2024. The Basics Brand: Grand SeikoModel: Kodo Constant-Force TourbillonReference Number: SLGT005Diameter: 43.8mmThickness: 12.9mmCase Material: Platinum 950 and titaniumDial Color: Open-workedWater Resistance: 100mStrap/Bracelet: White leather and charcoal grey leather straps The Movement Caliber: Caliber 9ST1Functions: Hours, minutes, seconds, constant-force mechanismPower Reserve: 72 hoursWinding: ManualFrequency: 4HzJewels: 44 Pricing & Availability Price: $365,000Availability: December 2024Limited Edition: Yes, 20 pieces Shop this story The Hodinkee Shop is an authorized retailer of Grand Seiko watches. For more on the Kodo Constant-Force Tourbillon, visit Grand Seiko online.