Chapter 1
Inheriting the DNA of Innovation, Spring Drive Continues to Evolve
Pursuing specifications befitting
Grand Seiko
Spring Drive is an innovative, high-precision, uniquely engineered movement born from the fusion of Japan’s world-renowned technology and master craftsmanship. Though the technology was first introduced in 1999, it was not until 2004 that Caliber 9R Spring Drive debuted as a Grand Seiko-exclusive movement. This was followed by the introduction of the Spring Drive Chronograph; by Calibers 9R01 and 9R02, crafted by the Micro Artist Studio; and by Calibers 9RA2 and 9RA5, both featuring five days of power reserve. In 2025, the Spring Drive U.F.A. Caliber 9RB2 was introduced, achieving an astounding accuracy of ±20 seconds per year.
This special site explores the evolution of Spring Drive—a groundbreaking movement powered by a mainspring and regulated by a quartz oscillator—through five stories. These narratives trace the continuous pursuit of precision from Spring Drive’s initial development to the present day.
Successfully implementing automatic winding in Spring Drive. Introducing it in Grand Seiko for the first time.
In 2004, Grand Seiko introduced its first model featuring the automatic winding Spring Drive Caliber 9R65, a development made possible through technological innovation. This movement has an automatic winding mechanism that winds the mainspring, generating energy to drive the watch’s hands. While this mechanism is similar to that of a traditional mechanical watch, Spring Drive is unique in that some of the energy is converted into electricity, using an integrated circuit (IC) and a quartz oscillator for regulation.
Spring Drive is the pinnacle of integration between mechanical watchmaking and quartz technology, an innovation pioneered by Seiko in the 1960s. Caliber 9R65 represented a significant advancement over its predecessor, the manual-winding Spring Drive Caliber 7R88: the power reserve increased from 48 hours to an impressive 72 hours while incorporating automatic winding.
Achieving a 72-hour power reserve with automatic winding
Extending Spring Drive’s power reserve from 48 to 72 hours and incorporating an automatic winding mechanism were essential milestones on the path to Grand Seiko’s use of the technology. The extended power reserver ensured that even if the watch were removed on a Friday night and left unworn over the weekend, it would still keep time on Monday morning without needing to be rewound.
The development team miniaturized the barrel while increasing the power reserve by 1.5 times. Key advancements included reducing mechanical loss due to friction, improving power generation efficiency, and enhancing the IC’s energy efficiency. Each of these developments leveraged the strengths of Seiko’s in-house manufacturing capabilities.
However, incorporating the automatic winding mechanism posed a more significant challenge than extending the power reserve. This was overcome by refining the “Magic Lever,” a compact, highly efficient, and durable automatic winding system. Originally developed by Suwa Seikosha (now Seiko Epson) in 1959, just a year before the first mechanical Grand Seiko was introduced in 1960, the Magic Lever has since been adopted in high-end Swiss automatic watches as well.
The hand glides smoothly on the dial without ticking
In a Spring Drive watch, the seconds hand does not tick but moves smoothly across the dial in a glide motion that embodies the natural flow of time itself. Powered by the unwinding force of the mainspring, the movement applies a magnetic brake 256 times per second to the regulator linked to the hands, precisely controlling their speed and achieving the seamless glide motion.
Heritage Collection SBGA413
The SBGA413 is a modern reinterpretation of the 62GS, Grand Seiko’s first automatic mechanical model, which was released in 1967. This creation is inspired by Japan’s micro seasons, or sekki, which divide the year into 24 seasonal phases and capture the subtle transitions of nature. The dial motif is that of hana-ikada, evoking the scene of cherry blossom petals falling onto a river’s surface, swirling and drifting as if dancing on the water. The watch is equipped with the automatic Spring Drive Caliber 9R65 and features a 40mm case and bracelet in High-Intensity Titanium.
Heritage Collection SBGA211
The ‘Snowflake’ dial beautifully expresses the magnificence of the snowy landscape in the Hotaka mountains, which can be seen from the Shinshu Watch Studio where this watch is crafted. When snow falls, as it does every winter, it forms into light, hard crystals that sparkle in the sun and, driven by the cold wind, create delicate patterns as they drift on the sharp, dry air. The dial is made by a special silver-plating process that allows the creation of the delicate texture of the snow to be replicated so perfectly. The second hand is made of steel tempered to a beautiful shade of blue, adding a striking contrast. The watch is powered by the automatic Spring Drive Caliber 9R65 and comes with a 41mm High-Intensity Titanium case and bracelet.
The Spring Drive development team continued their research and innovation beyond extending the power reserve and achieving automatic winding, striving to enhance functionality and design. As the ultimate fusion of mechanical and quartz watch technologies, the evolution of Spring Drive is an ongoing story of continuous advancement.
