Grand Seiko Masterpiece Spring Drive Limited Edition SBGZ007
The Grand Seiko Masterpiece Spring Drive Limited Edition SBGZ007 features a deep blue dial, beautifully engraved platinum case and a supremely precise hand-wound movement. However, with only 50 pieces available, there will inevitably be some watch aficionados that will miss out on this latest instalment of horological excellence.
As Seiko celebrates its 140-year anniversary, it continues to unveil more and more mouthwatering horological delights. Its latest creation, the Grand Seiko Masterpiece Spring Drive Limited Edition SBGZ007, coincides with the 20th anniversary of the Spring Drive, the brand’s ingenious movement that fuses the worlds of electronic and mechanical watchmaking.
Once again, the Japanese marque takes its own unique path to greatness. Indeed, it doesn’t seek to emulate German or Swiss watch brands but chooses to celebrate the culture of its home nation. Often its models are influenced by nature and sometimes they also encompass traditional Japanese artisanal crafts. The new Grand Seiko Masterpiece Spring Drive Limited Edition SBGZ007 is inspired by the clear skies above Achi, a mountainous area of the Shinshu region.
The dial is presented in a deep blue, enlivened with shimmering flecks of colour. Upholding the design language widely employed on Grand Seiko models, the watch is fitted with dauphine-style hour and minute hands, albeit in this instance they are made of 14-carat white gold. The hours are marked with elegant, faceted indexes, once again in white gold, with simple strokes positioned in between. A central sweep seconds hand completes the inventory of functions. It seamlessly glides around the dial, bestowing a sense of calm and indicating the watch is powered by a Spring Drive movement.
The dial sits beneath a dual-curved sapphire crystal, a detail found on many of the firm’s models. It invites light to flood the dial plane, augmenting legibility. A second pane of sapphire crystal is positioned to the rear of the watch, affording sight of the beautifully appointed Spring Drive movement, the Calibre 9R02.
Several models within the Grand Seiko collection are powered by Spring Drive movements, both in hand-wound and automatic form. However, the Calibre 9R02 sits on a higher plane than some of its siblings. It is made in the company’s Micro Artist Studio, home to several Credor models including the Spring Drive Sonnerie and the Eichi II. Having visited this modestly sized atelier, I can attest the standards I have witnessed are comparable with the finest exemplars of Swiss Haute Horlogerie.
Two dominant grained bridges are visible to the rear via the exhibition caseback. One bridge is fitted with a power-reserve indicator showing the amount of energy stored within. The cover of the barrel is open-worked, affording sight of the upper mainspring and replicates the appearance of a bellflower, the symbol of the Shiojiri region. The jewel and screw sinks, as well as the edges of the bridges, are polished to a gleaming conclusion. Unlike most movements, the single barrel contains two mainsprings in parallel. With most watches when the mainspring(s) is fully wound, there is often too much torque. Cleverly, this movement features a ‘Torque Return System’ which uses this excess torque and to rewind the mainspring. This is just one example of how Grand Seiko and its sister company, Credor, employ ingenious means to deliver advancement.
Like other Spring Drive movements, the Calibre 9R02 delivers incredible precision, surpassing the accuracy of many tourbillons. Grand Seiko states the precision as ‘±1 second per day (±15 seconds per month).
The case is formed of platinum 950 and embellished with a delightful hand engraved motif. The resultant finish includes tiny recesses that engage with light, thereby emitting a bewitching sparkling appearance similar to that of a precious stone. The case measures a reserved 38.5mm in diameter and just 9.8mm in depth, giving it a slender profile.
With the advent of this watch and some recent additions to the Grand Seiko portfolio, the distinction between the high-end Grand Seiko brand and the ultra high-end Credor models is becoming increasingly blurred. With only 50 pieces available, I suspect demand will significantly outstrip supply.
The brand’s press release (June 2021)
High up in the mountains of the southern part of Japan’s Shinshu region is Achi, a village that is famous for its spectacular night skies. Thanks to its high elevation, its remoteness and the crisp cleanliness of its air, the stars above Achi seem almost within touching distance and the immensity of the universe is brought into the sharpest focus. With its platinum case and with the glide motion seconds hand that moves silently and continuously across the deep blue, star-speckled dial, this new Grand Seiko masterpiece brings to life both the majesty of the heavens and the ever-changing and yet eternal nature of time itself.
When the Spring Drive manual-winding calibre 9R02 was first presented in 2019 to mark the 20th anniversary of Spring Drive, it won favour among watch enthusiasts worldwide for its delicate yet understated refinement. With its hand-crafted quality and with the glide motion seconds hand that is the signature of Spring Drive, it exemplified Grand Seiko’s uniquely Japanese sensibility.
Today, in celebration of the 140th anniversary of the foundation of the company, Grand Seiko presents a new Spring Drive masterpiece powered by this caliber and made by the elite team
of watchmakers at the Micro Artist Studio in Grand Seiko’s manufacturing facility in Shiojiri, located in the same Shinshu region as Achi. The watch will be available as a limited edition of 50 at the Grand Seiko Boutiques in August 2021.
The blue of the dial has a remarkable depth that is accentuated by the quiet and delicate sparkle of what appear to be distant stars. A unique manufacturing and finishing technique combining stamping, plating and painting gives the dial a different aspect at each and every viewing angle, just as does the sky above Achi. The Platinum 950 case is carefully engraved with a pattern which is replicated in different directions on the Zaratsu polished case, again capturing the exquisite order and ever changing aspect of Achi’s starry skies.
The watch presents a refined and slim profile with a diameter of 38.5mm and depth of 9.8mm. The hour and minute hands and hour markers are made of 14k white gold to ensure that their brilliance endures for decades. The Grand Seiko name, the minute markers and all the other markings are etched into the dial.
Created and assembled in the Micro Artist Studio
Every aspect of the movement is designed without compromise. The power reserve indicator is on the back side of the movement next to the barrel whose shape echoes that of the bellflower that is the symbol of Shiojiri. The rims of the bridges, the holes for the rubies and the screws are all expertly hand polished to a perfect mirror finish and the tempered blue screws stand out in contrast to the hairline finish of the bridges to heighten the perception of the perfection of the engineering. The calibre also incorporates an 18k yellow gold plaque on the lower bridge, which carries the engraved words “Micro Artist” but which can, if the owner so wishes, be replaced with a word of his or her choice.
The movement is assembled and adjusted by the craftsmen and women in the studio including Katsumi Nakata, who has been recognized as a Contemporary Master Craftsman and is now the third member of the Micro Artist Studio team to have received the Medal with Yellow Ribbon from the Japanese government.
The outstanding 84-hour power reserve of Caliber 9R02 is realised thanks to the Dual Spring Barrel, in which two mainsprings are set in parallel within a single barrel, and the Torque Return System. When the mainspring has been fully wound and the torque output is at its highest, approximately 30% of the available power is not needed to maintain the precision of the watch and is in effect wasted in a normal movement. The Torque Return System uses this energy to rewind the mainspring, resulting in an increase in the power reserve. In Caliber 9R02, this system is activated for 48 hours after the mainspring has been fully wound.
About the Micro Artist Studio
The Micro Artist Studio is a luxury watch studio that makes the Grand Seiko Masterpiece Collection, a series of unique watches that combine the best in horological technology with hand craftsmanship of the highest order. The studio was established in 2000 with the purpose of “uncovering, examining, and mastering the technologies and skills passed on by our predecessors for the production of luxury watches”. The team consists of craftsmen and women, each an expert in their respective fields, such as movement design, assembly and movement finishing.
Further reading