Grand Seiko's unique Spring Drive design explained

As a "high-performance luxury watch," Spring Drive offers outstanding precision and reliability, making it one of Grand Seiko's flagship models. We explore the originality of this third movement, which combines the benefits of both mechanical and quartz movements, and introduce watches equipped with it, from the latest models to classic favorites.

Grand Seiko with high technical capabilities

　Seiko released the world's first mass-produced quartz wristwatch in 1969, and developed and commercialized the world's first Spring Drive wristwatch in 1999. Grand Seiko offers a collection of watches with three types of movement systems: mechanical, quartz, and Spring Drive.

　Spring Drive is manufactured at Shinshu Toki no Takumi Kobo in Shiojiri, Nagano Prefecture, which has inherited the tradition and passion that has continued since the days of Suwa Seikosha, the company that manufactured the first Grand Seiko.

　Before we discuss Spring Drive, let's take a look at Grand Seiko's high-level technical capabilities and global expansion.

A domestic brand on par with the world

　Grand Seiko was launched by Seiko in 1960 as a domestic brand that achieved high precision comparable to luxury Swiss watches.

　The following year, import tariffs were relaxed, intensifying competition with overseas forces, but Grand Seiko continued to increase its competitiveness by improving its technological capabilities.

　Eventually, sales grew in both domestic and international markets, leveraging the strengths of its precision and reliability in mechanical and quartz movements, as well as the third drive system, the "Spring Drive" movement. However, the impression was that Grand Seiko was primarily used for business purposes.

　Meanwhile, in 2017, Grand Seiko became independent from other brands owned by Seiko.

　Grand Seiko has been reborn as a luxury watch brand that not only produces watches for business use, but also dress watches and sports watches, and in 2020, marking its 60th anniversary, the brand further accelerated its expansion into overseas markets.

High technical capabilities and manufacture

　Grand Seiko aims to create the pinnacle of precision and practicality in its watches, and makes no compromises in its watchmaking, from movement design to parts manufacturing, polishing, and casing.

　Grand Seiko mechanical watches are manufactured by Grand Seiko Studio Shizukuishi (Shizukuishi Town, Iwate Prefecture), while quartz and Spring Drive watches are manufactured by Shinshu Toki no Takumi Kobo (Shiojiri City, Nagano Prefecture). Needless to say, both are world-class manufacturers.

　Shinshu Toki no Takumi Kobo produces high-precision 9F quartz movements with an annual accuracy of ±10 seconds, and has spent over 20 years perfecting the revolutionary Spring Drive movement system.

　Shinshu Toki no Takumi Atelier consists of four workshops: the Micro Artist Workshop, the Takumi Workshop, the Dial Workshop, and the Case Workshop. The Micro Artist Workshop, in particular, brings together elite technicians, and in 2016 released the special Spring Drive movement "Cal. 9R01," which boasts a power reserve of up to approximately eight days.

　The latest generation of Spring Drive, the Caliber 9RA5, was released in 2020. At just 5mm thick, the movement is significantly thinner, yet boasts an extended power reserve of approximately 120 hours. Accuracy has also been improved, from ±15 seconds per month to ±10 seconds per month.

　Furthermore, in 2025, the Cal. 9RB2 will be released, featuring an even smaller movement with an extremely high accuracy of ±20 seconds per year. With a diameter of 30mm and a thickness of 5.02mm, this new model, housed in a 37mm case, will be named "UFA (Ultra Fine Accuracy)," following on from the "Grand Seiko VFA (Very Fine Adjusted)" that was released in 1969.

　These new movements are not rare special editions, but are being installed in regular models one after another as next-generation flagship models.

What is Spring Drive?

　While many long-established watch manufacturers continue to pursue complex mechanisms, Seiko and Grand Seiko are known for making fundamental improvements to their drive systems. Spring Drive is one symbol of this. Let's take a look at what Spring Drive is and its unique mechanism.

Drive mechanism developed using proprietary technology

　Spring Drive, which was born in 1999, is an innovative drive system that combines the advantages of both mechanical and quartz movements. This revolutionary mechanism was created by Shinshu Toki no Takumi Kobo after more than 20 years of research and development, and is currently used in Seiko, Grand Seiko, and Credor watches.

　In 2004, the Spring Drive Caliber 9R65, an automatic movement exclusive to Grand Seiko, was completed, boasting the quality befitting a luxury watch.

　The high-precision movements, which involve over 200 precision parts for three-hand models and over 400 for chronograph models, are processed and adjusted by skilled craftsmen to within 0.01mm, and have earned high praise both domestically and internationally.

The differences between quartz watches, mechanical watches, and Spring Drive watches

　Quartz watches are battery-powered and consist of a crystal oscillator that vibrates when voltage is applied, an IC that converts this vibration into a frequency per second, and in the case of analog watches, a step motor that moves the hands. While it is easy to ensure accuracy and is suitable for mass production, the torque is small, making it difficult to move heavy hands and to incorporate additional mechanisms.

　Mechanical watches are powered by the force generated by the unwinding of a wound mainspring, and are regulated by mechanical structures such as a hairspring, balance, anchor, and escape wheel. They have a large torque and are suitable for incorporating complex mechanisms, but there is a large difference in vibration frequency compared to quartz watches, and there are limits to the accuracy they can achieve.

　The Spring Drive can be said to combine the features of both quartz and mechanical watches, as it uses the mainspring as its power source and is regulated by an IC and quartz crystal oscillator, allowing it to achieve both high torque and high precision.

Spring Drive video

The benefits of Spring Drive

　Grand Seiko's Spring Drive is not simply a combination of mechanical and quartz movements. Let's take a look at the benefits of using Spring Drive, which pursues functionality, precision, and reliability worthy of a luxury watch.

The sweeping movement of the hands is smoother than that of a mechanical watch

　The hand movement method differs depending on the movement's regulating mechanism. In mechanical watches, the second hand moves in sync with the back-and-forth motion of the balance, resulting in a "beat hand" that ticks away precisely. In contrast, in quartz watches, the IC-controlled rotor rotates in precise one-second increments, resulting in a "step hand" that rotates once every 60 steps.

　In Spring Drive, the rotor rotates continuously in one direction, maintaining a constant rotation speed by comparing the frequency of the quartz oscillator with the rotation speed of the rotor using IC control.

　This special regulating mechanism enables the hands to sweep smoothly across the dial without the noise or ticking that comes from reciprocating motion.

High accuracy of ±15 seconds per month

　Spring Drive is driven by a mainspring just like a mechanical watch, but like a quartz watch, it is precisely regulated by an IC and a quartz oscillator.

　This unique mechanism allows Spring Drive to achieve high accuracy with an average monthly rate of ±15 seconds (equivalent to a daily rate of ±1 second).

　Cal. 9R01 boasts a continuous running time of approximately 8 days, and the Cal. 9R96 automatic chronograph movement has been specially adjusted for high precision, achieving even higher accuracy of ±10 seconds per month (equivalent to ±0.5 seconds per day).

Torque equivalent to that of a mechanical watch

　If a quartz movement is used for high accuracy, the torque will be small due to the motor drive, but if a mechanical movement is used to move heavy, thick, and long hands, the torque will be large but the accuracy will be lower.

　However, Spring Drive uses a mainspring as its power source, just like a mechanical movement, allowing the hands to move gracefully and with the majestic style that is characteristic of Grand Seiko.

　It is silent, smooth, and highly accurate, achieving quality that exceeds that of a mechanical watch.

Disadvantages of Spring Drive

　Let's also take a look at some points to be aware of due to the characteristics of Spring Drive.

Fewer options than other movements

　Because Spring Drive is a mechanism unique to Seiko, the number of models equipped with it is limited compared to quartz and mechanical watches.

　The same can be said for Grand Seiko's lineup. Currently, there are fewer Spring Drive models than quartz and mechanical models, and some of them are rare. However, we can expect the lineup to expand in the future as a core product for the global market.

High average price

　Grand Seiko watches range in price from 30 to 100 million yen, with entry-level quartz models available for around 20 yen.

　However, Spring Drive prices start from around 60 yen, with many models costing over 100 million yen, and the special edition platinum case model Ref. SBGZ003 is priced at 770 million yen (tax included).

　Spring Drive movements have over 200 parts, and chronograph movements have over 400. Although they are somewhat expensive, this quality and production costs also contribute to their rarity.

Regular repairs by the manufacturer are the norm

　To keep your watch in good condition for a long time, it is essential to have it overhauled regularly. And of course, if a malfunction occurs, repairs are also necessary.

　In the case of quartz or mechanical watches, you may consider taking the watch to a specialist watch repair shop, but in the case of models equipped with Spring Drive, it is best to contact an authorized service center.

　Since Spring Drive is a mechanism used only by Seiko, Grand Seiko, and Credor, it is safe to assume that no one other than the manufacturer has the know-how to repair it or the parts to buy it.

Recommended Spring Drive watches! Introducing the latest and most popular models

　Grand Seiko has traditionally focused on designs aimed at business people, but as it accelerates its global expansion, it is showing an attitude of challenging itself with new designs and mechanisms, centered around Spring Drive.

　We will introduce five models that are well suited to business situations and have excellent design and functionality.

Ultra-High-Precision Spring Drive Ref. SLGB005, "UFA," to be Released in 2025

　In 2025, the Cal. 9RB2 was released as a super-high precision movement with an annual accuracy of ±20 seconds, featuring a thin, small diameter Spring Drive movement with a diameter of 30mm and a thickness of 5.02mm. The Ref. SLGB005, featuring this movement, has been added to the Evolution 9 Collection, featuring a dial depicting the mystical scene of dawn as the frost-covered forests of the Shinshu region quietly awaken.

　The dial features Grand Seiko's signature delicate embossed pattern and is given a violet color that stands out even in its quietness, creating a unique atmosphere.

　The case and bracelet are made from high-performance Everbrilliant Steel, also known as "super stainless steel." This material has excellent corrosion resistance, allowing you to enjoy its beauty for years to come.

The Ref. SLGA009, also known as the "White Birch," is equipped with the next-generation Spring Drive.

　In 2020, Grand Seiko introduced the Caliber 9RA5, the latest generation of Spring Drive movements. This movement boasts a slim design and a long power reserve of approximately 120 hours. The Caliber 9RA2, which featured a power reserve indicator on the case back, was released in 22. This model is the first to be released with the Caliber 9RA2.

　The Evolution 9 Collection inherits the Seiko design established with the 44GS in 1967, while incorporating the Japanese sensibility of finding beauty "between light and shadow," and aims to further evolve essential legibility and wearability, incorporating a new design grammar. The slim design and low center of gravity of the case make it comfortable to wear.

　Another distinctive feature is the dial design, inspired by the birch forests that grow in abundance near Shinshu Toki no Takumi Kobo. The blue second hand stands out against the dial, which depicts a snow-covered birch forest with a delicate embossed pattern.

　This is a watch that truly captures the essence of Grand Seiko watchmaking, both in its mechanism and exterior.

The beautiful pure white dial of the Ref. SBGA211, commonly known as "Snow White"

　The Heritage Collection's "SBGA211" is a model that combines lightness and elegance, featuring a "snow-white" dial with a motif of wind-etched snow. Inspired by the snowfall of the Hodaka mountain range, which towers over the birthplace of Spring Drive, the snow-white dial is also known as "snowflake" and is popular overseas.

　The case is made of bright titanium, which is about 30% lighter than stainless steel, and weighs just 100g. The case diameter is 41mm, which is a comfortable size for wearing.

　The power reserve is approximately 72 hours, so even if you take it off on Friday night, it will still be running fine on Monday morning.

Ref.SBGY007, inspired by the Suwa Shrine Crossing

　This Spring Drive model features a dial depicting the natural phenomenon known as "Omiwatari," which occurs when Lake Suwa in Shiojiri, Nagano Prefecture, where Shinshu Toki no Takumi Kobo is located, freezes over completely in the middle of winter.

　In addition to the delicate dial pattern, the watch is hand-wound, with no rotor to wind the mainspring via wrist movement, and its slim 10.2mm case further accentuates its elegant style.

Ref. SBGE283 with GMT function

　In 2020, the Evolution 9 collection introduced a full-fledged sports watch, and this is one of the Spring Drive models equipped with a GMT function.

　The high-quality case, with its distinctive ridges and crown guard, is characteristic of the Evolution 9 collection, and exudes a sporty feel. The 24-hour display is printed directly on the bezel, giving it the look of a tool watch.

　The case diameter is a moderate 41mm, and it has a power reserve of up to approximately 72 hours, so it will be a great choice as your main watch on weekdays.

Ref. SLGA015, suitable for marine sports

　The SLGA015 is a full-fledged diver's watch model equipped with the next-generation Spring Drive Cal. 9RA5, 200m water resistance, and a rotating bezel for diving. The case is large at 43.8mm, but thanks to the use of bright titanium, it weighs just 150g, which is not too heavy for a sports watch. It also boasts excellent scratch and corrosion resistance.

　The dial pattern is delicately finished to represent the powerful ocean currents that flow around Japan, including the Kuroshio Current.

　The hands, indexes, and bezel are coated with Lumibrite luminous paint, making them easy to read at night or in dark places.

　With a power reserve of approximately 120 hours, excellent accuracy of ±10 seconds per month, and water resistance to 200m, it is sure to be versatile and can be worn in a variety of situations.

Enjoy a hybrid of quartz and mechanical movements

　The story of Grand Seiko's manufacture has had a profound impact on the watch industry, and now in the 21st century, it aims to reach even greater heights with Spring Drive.

　Wear a Grand Seiko Spring Drive model and experience the innovation and convenience of this movement.