The Grand Seiko Hand-Wound Spring Drive Collection

As you may already know, Seiko is celebrating the 20th anniversary of its Spring Drive technology this year. To mark what is in fact quite a momentous occasion, Grand Seiko debuted two new hand-wound Spring Drive movements and a total of four different watches at Baselworld. We recently spent some hands-on time with three of them and have once again been blown away by Grand Seiko’s flawless finishing and attention to detail.

Spring Drive

Brice already covered the Spring Drive technology comprehensively in his review of the highly desirable Snowflake, so I’ll only touch on it again briefly here. Essentially it combines elements of mechanical and quartz watchmaking to create a hybrid movement that delivers superior performance and accuracy. What sets it apart from a traditional mechanical movement is the use of a regulating organ that is equipped with an exclusive speed control mechanism, incorporating an IC, an electronic brake and a quartz crystal. This results in an average monthly rate of ±15 seconds (or ±1 second per day on average) and a minimum power reserve of around 3 days.

Given the significance of this technology to Seiko, and indeed to modern watchmaking, it seems only fitting that Grand Seiko should package it up as beautifully as possible. And that’s exactly what it has done.

Case

The first thing to note about these new models is how slim and refined the cases are. Their aesthetic is very much informed by the new Elegance Collection, also debuted by Grand Seiko this year at Baselworld. All four cases measure a comfortable 38.5mm in diameter and are refreshingly thin. The two platinum models – SBGZ001 and SBGZ003 – stand just 9.8mm tall, while the yellow gold and steel versions – SBGY002 and SBGY003 – are slightly thicker at 10.2mm (due to the use of a different movement).

The cases are shaped in such a way that they sit very flat against the wrist, which makes them exceedingly comfortable to wear. It’s also very befitting of a dress watch, which should easily slide away under a shirt cuff. To my eye, the integrated design between the caseband and the lugs also gives the visual impression that the cases are slightly larger than 38.5mm. I think this is good news for those who like the refined style but worry that the dimensions will be too small. Personally, I think this is just about the perfect size for a dress watch.

The two platinum models are the work of the Micro Artist Studio, and both have been assembled and finished by hand. The case of one of them – SBGZ001 – has been entirely hand-engraved with a Snowflake pattern (matching the dial) – unfortunately not available when photographing the watches. According to Grand Seiko, the design is inspired by the beauty of the snow in the Shinshu region, which is where the Studio is located. It’s a delicate and painstaking process, with no two cases looking exactly alike. Not surprisingly, this version is limited to just 30 pieces. The other three models – in platinum (SBGZ003), gold (SBGY002) and steel (SBGY003), respectively – have all been classically polished to Grand Seiko’s very high standards, meaning according to the Zaratsu technique.

Dial

The dials of all four models are relatively simple and understated but that does not mean they are not eye-catching. Far from it. In fact, simple is where Grand Seiko really comes into its fore. The limited-edition platinum model features a silvery-white Snowflake pattern engraved on its dial, as does the non-limited yellow gold model. The other platinum model features a silvered dial with a grained finish, while the silvery dial of the steel model is embellished with an eye-catching sunray pattern. On the platinum and steel versions, the hour and minute hands and hour markers are made of 14k white gold. This switches to yellow gold for the yellow gold version.

In typical Grand Seiko fashion, the hands and indexes are super sharp and crisp. You really have to look at them under a loupe to fully appreciate the attention to detail paid in their finishing. The Grand Seiko name, the minute markers and all the other markings are etched into the dial, and in all four examples, a blued steel seconds hand provides just a touch of contrast to the dial. It goes without saying that the dials are super legible but also just really gorgeous to look at, especially when the light hits just right.

Movement

Of course, the real treat is what’s inside these watches. The Grand Seiko Spring Drive SBGZ001 and SBGZ003 (the two platinum models) are both equipped with the newly developed hand-wound movement, calibre 9R02. The exclusive work of the Micro Artist Studio, it has two mainsprings set in parallel within a single barrel and uses the unique Torque Return System* to generate 84 hours of power. A power reserve indicator is visible through the sapphire crystal caseback, next to the bellflower-shaped barrel. For those who are curious, the bellflower is the symbol of Shiojiri, where the Micro Artist Studio is located.

As you would expect at this level, the movement is hand-finished and hand-assembled. The edges of the two bridges have been painstakingly polished to perfection, providing a striking contrast with the hairline finish of the bridges themselves. Again, the appearance is relatively simple, but the execution is just on another level. Accuracy is in the order of ± 1 second per day.

*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 Calibre 9R02, this system is activated for 48 hours after the mainspring has been fully wound.

The Grand Seiko Spring Drive SBGY002 and SBGY003, meanwhile, house a new hand-wound Spring Drive movement, calibre 9R31. This in-house movement is crafted at the Shinshu Watch Studio (next to the Micro Artist Studio) where all other Grand Seiko Spring Drive watches are made. It shares the same dual mainspring structure as calibre 9R02 but doesn’t use the Torque Return System. This results in a slightly lower but still sufficient power reserve of 72 hours. Precision remains unchanged, however, at the highly accurate rate of ± 1 second per day.

Strap

All four models are delivered on a crocodile leather strap with a three-fold clasp with push-button release. The yellow gold version features a brown strap, while the other three are all black. They’re comfortable on the wrist and tie in nicely with the overall dress watch theme.

Price and availability

Pricing varies quite significantly. The platinum models are EUR 78,000 (SBGZ001, limited to 30 pieces) and EUR 58,500 (SBGZ003) respectively. While the Yellow Gold Grand Seiko Spring Drive SBGY002 is EUR 27,000, and the stainless steel Grand Seiko Spring Drive SBGY003 is EUR 8,200. Please note, however, that the steel version is limited to 700 pieces worldwide.

More details at www.grand-seiko.com.

Technical Specifications SBGZ001 – SBGZ003

• Case: diameter 38.5mm x thickness 9.8mm – 950 platinum, hand-engraved (SBGZ002) or polished (SBGZ003) – high definition dual-curved sapphire crystal with anti-reflective coating – see-through screw caseback – 30m water-resistant
• Dial: silvered, with or without snowflake pattern – hands and hour markers in 14k white gold
• Movement: calibre 9R02, in-house – hand-wound with Spring Drive technology – 84h power reserve – accuracy of ± 1 second per day (± 15 seconds per month) – Dual-Spring Barrel and Torque Return System – 39 jewels – assembled at the Micro Artist Studio by hand – hours, minutes, seconds, power reserve (back)
• Strap: crocodile strap with three-fold clasp with push-button release
• References: SBGZ001 (engraved), limited edition of 30 – SBGZ003 (polished), not limited
• Price: EUR 78,000 (SBGZ001) – EUR 58,500 (SBGZ003)

Technical Specifications SBGY002 – SBGY003

• Case: diameter 38.5mm x thickness 10.2mm – 18k yellow gold (SBGY002), stainless steel (SBGY003) – high definition dual-curved sapphire crystal with anti-reflective coating – see-through screw caseback – 30m water-resistant
• Dial: silvered – snowflake pattern (SBGY002) – sunray pattern (SBGY003)
• Movement: calibre 9R31, in-house – hand-wound with Spring Drive technology – 72h power reserve – accuracy of ± 1 second per day (± 15 seconds per month) – Dual-Spring Barrel – 30 jewels – hours, minutes, seconds, power reserve (back)
• Strap: crocodile strap with three-fold clasp with push-button release
• References: SBGY002 (gold) – SBGY003 (steel), limited to 700 pieces
• Price: EUR 27,000 (SBGY002) – EUR 8,200 (SBGY003)