Grand Seiko SLGB003 Spring Drive U.F.A. Watch Review
The Grand Seiko SLGB003 Spring Drive U.F.A., presented in a titanium case, has just been unveiled at Watches & Wonders 2025. It is joined by its ultra-noble platinum encased sibling, the SLGB001. Both models are modestly sized, measuring 37 mm in diameter and yet are packed with technical ingenuity. The brand’s watchmaking expertise is manifest with an annual rate of ±20 seconds, granting an unprecedented degree of precision for a mainspring-powered watch. Angus Davies, a self-confessed GS fan examines these latest creations in minute detail.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
Grand Seiko watch – ownership delight
Over the years, I’ve met several fellow Grand Seiko obsessives. We are a naturally inquisitive bunch of horophiles who look beyond brand ambassadors and sports sponsorship, preferring to focus our attention on product attributes. For many GS fans, the process of seduction began on seeing a dial for the first time.
When creating dials, Grand Seiko has repeatedly found inspiration in the countryside close to its Studios in Shizukuishi (4Hz and 5 Hz movements) and Shinshu (Spring Drive and quartz movements). On other occasions, the company has incorporated traditional Japanese artisanal crafts such as Urushi Maki-e. Some GS dials are imbued with texture or depths, but all share one trait in common; they are optimised to deliver peerless readability. The ease of reading is heightened with expertly polished fulsome hour and minute hands that collaborate with applied hour markers to impart meaning.
Looking beyond the alluring charms of a dial, a GS newbie will undoubtedly go on to be seduced by the allure of a Zaratsu polished case and bracelet ensemble; a pairing that bestows distortion-free case reflections and an ergonomic fit par excellence.
And lastly, Grand Seiko seals the deal by equipping each reference with an ultra-precise movement. When the Japanese company was established in 1960, it sought to create a watches that delivered a suite of attributes, including precision. Thereafter, the company has never wavered in its quest to produce increasingly precise movements. Indeed, it has embraced new technologies such as MEMS, developed Hi-Beat 36000 movements (5 Hz) and even created a dual-impulse escapement (the Calibre 9SA5).
The sign of a true GS devotee is a person who is conversant with the brand’s historic Calibres. They know the difference between 4 Hz and 5 Hz, Spring Drive and Quartz and Swiss lever and dual-impulse escapements. However, even the most ardent GS fan may be unfamiliar with the brand’s three-letter acronyms. Allow me to elaborate.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
Grand Seiko V.F.A.
Back in 1969, as part of its unwavering quest to produce increasingly precise movements, Grand Seiko unveiled a mechanical movement, the Calibre 6185 (5 Hz). It featured within a new model, the 61 GS V.F.A., and delivered an accuracy of ± 1 minute per month. This was the first of several V.F.A. (Very Fine Adjusted) mechanical movements released between 1969 and 1972.
Spring Drive U.F.A.
With a history of making V.F.A. branded models, Grand Seiko has now chosen to unveil a new movement, the Calibre 9RB2, again bearing three-initials. However, unlike said V.F.A. models, each of which was equipped with a mechanical movement featuring a Swiss-lever escapement (5 Hz), the new generation Calibre 9RB2 is a Spring Drive movement bearing a new set of initials, U.F.A. (Ultra Fine Accuracy).
Remarkably, the automatic U.F.A. movement (Calibre 9RB2) has an ‘annual rate of ±20 seconds, making it the most accurate movement powered by a mainspring today’. To provide context, for a conventional mechanical movement to be certified as a chronometer by COSC (Contrôle Officiel Suisse des Chronomètres), the average daily rate must be -4 to +6 seconds per day.
Image – Grand Seiko Calibre 9RB2
The flow of time
Most mechanical watches contain a mainspring which is tensioned either by manually winding the crown or by an oscillating mass that harnesses the natural motion of the wrist. With a conventional watch, the mainspring transfers energy through a series of wheels, termed the gear train, to a Swiss-lever escapement.
The escapement has two roles. It serves an ‘impulse’ to the balance wheel (similar to a pendulum within a clock) and it also momentarily unlocks the gear train, causing the hands to advance a predetermined amount. The period between the locking/unlocking phases is determined by the balance wheel, with a balance spring at its centre, oscillating to and fro. This choreographed locking/unlocking action is referred to as ‘the flow of time’.
The story of the Grand Seiko Spring Drive
In 1977, Yoshikazu Akahane, a young watchmaker, having witnessed the development of quartz movements, conceived a wholly new form of movement. His idea was to make a calibre incorporating a mainspring, tensioned manually or using an oscillating weight, but with a very different means of controlling the flow of time. His system ultimately became known as ‘Spring Drive’.
The story of Spring Drive is one of persistence. Indeed, it wasn’t until 1999, shortly after Akahane’s passing, that the first Spring Drive movements were unveiled at Baselworld (Seiko Calibre 7R68 and the Credor Calibre 7R78). Later, in 2004, Grand Seiko released the SBGA003, the first GS-branded Spring Drive watch, equipped with the Calibre 9R65.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
It’s rare for a watch company to spend 27 years developing a movement; I suspect most firms would have given up long before. But then again, it’s rare to find a movement capable of delivering such remarkable precision, powered purely by a mainspring without a battery in sight.
How does Spring Drive work?
With a Spring Drive movement, some of the torque from the mainspring is sent to a ‘Tri-Synchro Regulator’, a component which translates some of the mechanical power into electrical power. This electrical power excites a quartz oscillator at a frequency of 32,768 Hz which provides a reference signal to an integrated circuit. The remaining power from the mainspring is transmitted through a series of wheels ultimately serving the glide wheel. The integrated circuit controls the rotation of the glide wheel, applying an electromagnetic brake as needed to ensure it rotates precisely eight times per second.
Unlike a conventional balance wheel, the glide wheel is unidirectional, something that is apparent when observing the centre seconds hand rotate. Moreover, unlike a movement featuring a Swiss-lever escapement, the centre seconds hand doesn’t tick, instead it serenely glides; a characteristic much loved by GS obsessives.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
A notable benefit of the Spring Drive movement is precision. When Grand Seiko unveiled the aforementioned SBGA003, its movement, the Calibre 9R65, delivered a stated accuracy of ±15 seconds per month.
Grand Seiko Spring Drive Calibre 9RB2
Since it was founded in 1960, Grand Seiko has continuously strived to make technical improvements. The Calibre 9RB2, with ‘the new U.F.A. designation’, has an ‘annual rate of ±20 seconds’, representing a new chapter in the history of mainspring powered watches. Given the already impressive precision of the Calibre 9R65, how has Grand Seiko surpassed its performance with the new U.F.A.? Allow me to explain.
Image – Grand Seiko Calibre 9RB2
The company grows quartz crystals in-house within an autoclave using high temperature and pressure. The development process takes approximately 90 days. One explanation provided by Grand Seiko for the new Calibre 9RB2’s notable performance relates to the ‘new and enhanced manufacturing and processing methods’ for the quartz oscillator. In addition, the Japanese marque points out that the Calibre 9RB2 incorporates a newly designed IC (Integrated Circuit).
Image – quartz crystals just being removed from an autoclave
When growing crystals, there will inevitably be small variances with each reacting to temperature slightly differently. These variations are addressed by a low-power IC, ensuring each crystal oscillates at the desired frequency of 32,768 Hz. Consistent with the existing 9RA series Spring Drive movements, ‘both the oscillator and sensor are vacuum-sealed to minimise temperature differences and protect against external factors such as humidity, static electricity, and light, ensuring precise temperature adjustments and stable performance of the quartz oscillator’.
Image – Grand Seiko quartz crystal
Furthermore, Grand Seiko has added another feature to the new Calibre 9RB2, namely a ‘regulation switch’. The movement is marked with ‘+’ and ‘-’ symbols, providing a trained watchmaker with the means to adjust the regulation of the watch should any inaccuracies occur over time. Clearly, Grand Seiko would not advocate owners regulating their watch; however, by introducing a simpler means of adjustment it should help mitigate service times/costs.
Beyond the technical merits of the Calibre 9RB2 there are a plethora of additional features worth mentioning. To the rear of the Grand Seiko SLGB003 Spring Drive U.F.A., a pane of sapphire crystal affords sight of the movement. The oscillating mass is partially openworked and bears the inscription, ‘SPRING DRIVE ULTRA FINE ACCURACY’. A power-reserve indicator is visible on the verso side of the movement, succinctly indicating the available energy within the barrel.
The movement is adorned with a frosted finish, inspired by the wintry appearance of the ‘trees of Shinshu, where all Grand Seiko Spring Drive watches are made’. Furthermore, the edges of the movement are mirror-polished and bevelled.
Assuming the mainspring is fully tensioned, the Calibre 9RB2 will operate autonomously for 72 hours.
Grand Seiko SLGB003 Spring Drive U.F.A. – dials
As stated earlier, Grand Seiko frequently references Japan’s beautiful scenery, often capturing its dynamic behaviour with the changing seasons. On this occasion, the brand has looked to the Kirigamine Highlands, east of Shinshu Watch Studio. Located close to Mount Kurumayama, the landscape features trees that don icy coats during the harsh winter months. The dial of the Grand Seiko SLGB003 Spring U.F.A emulates the appearance of this frosty scene with its intricately textured epidermis and its pale blue hues and silvery accents. The dial of the Grand Seiko SLGB001 Spring U.F.A is dressed in a slightly deeper shade of blue, complementing its platinum torso.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
Both the SLGB001 and SLGB003 subscribe to the Evolution 9 Style first introduced in 2020 with the release of the SLGH002. This design language influenced: aesthetics, legibility and wearer comfort.
Image – Grand Seiko Evolution 9 Style
Focussing on legibility, the Evolution 9 Style shares a resemblance with the 44GS design of 1967 but is more contemporary. The facetted hour and minute hands are an evolution of the traditional dauphine-style hands; however, the hour hand is notably broader and incorporates a central groove and a truncated tip. The trapezoidal indexes also feature a central groove, readily engaging with light, while the index at 12 o’clock is larger and endowed with two grooves. A date display resides at 3 o’clock and the dial is fringed with a minute track. Both references are equipped with a centre seconds hand, but Grand Seiko has chosen to differentiate the SLGB001 from the SLGB003 by equipping the platinum watch with a silver-coloured hand and the titanium reference with a blue hand.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
Upholding GS convention, both models carry additional text adjacent 6 o’clock referencing the presence of a ‘Spring Drive’ movement and ‘UFA’.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
Grand Seiko SLGB003 Spring Drive U.F.A. – case
The SLGB003 Spring Drive U.F.A. adheres to the Evolution 9 Style, juxtaposing ‘hairline’ and mirror-polished surfaces. The upper bezel is adorned with vertical lines running north to south (hairline). This treatment is repeated on the upper lug surfaces and the caseband. Grand Seiko has chosen to execute the bevelled edge of the bezel in a mirror-polished finish. This gleaming treatment is repeated on the angled edge between the upper lugs and caseband. By placing contrasting finishes in close proximity, GS accentuates the crisp lines that demarcate one finish from the other. Moreover, this blend of surface treatments wonderfully plays with light and shadow in a seemly way.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
Surprisingly, despite housing much complexity, the SLGB003 Spring Drive U.F.A. measures a mere 37 mm in diameter, a size that will no doubt win many fans. As mentioned earlier, one of the objectives when developing the Evolution 9 style was to heighten wearer comfort. Grand Seiko has achieved this by reducing the watch’s centre of gravity, making it sit closer to the skin. One example of how it has done this is by moving from a flush-fitting sapphire crystal to a box-shaped sapphire, thereby reducing the height of the bezel.
Image – Grand Seiko SLGB001 Spring Drive U.F.A.
Grand Seiko has also looked closely at the ratio between the bracelet and the watch head, increasing the width from 50% to 55%, making the watch more stable on the wrist and thereby more comfortable.
Image – Grand Seiko SLGB003 Spring Drive U.F.A.
The platinum SLGB001 Spring Drive U.F.A. is presented on a black crocodile strap, while the SLGB003 is presented on a titanium bracelet equipped with a ‘three-step micro-adjustment clasp’. This feature allows the wearer to adjust the bracelet in 2 mm increments, without the need for tools, to achieve the optimum fit.
Grand Seiko SLGB003 Spring Drive U.F.A. – closing remarks
While the SLGB003 Spring Drive U.F.A. is new, it remains undoubtedly a product of Grand Seiko. Eminently legible, the dial is also beautiful to behold. It transcends functionality to deliver a nature-inspired vista that is rich with character and emotion.
Furthermore, GS devotees will undoubtedly appreciate the brand’s near-obsessive attention to ergonomics, where the interaction between wrist and watch is considered in minute detail. Perhaps most surprisingly, despite its technical complexity, the SLGB003 measures only 37 mm in diameter, contrary to the idiom, ‘the bigger the better’.
But ultimately, I have to talk about movements. When Grand Seiko released the SBGA003 in 2004, its Spring Drive movement, the Calibre 9R65, was groundbreaking, delivering an unprecedented level of accuracy (±15 seconds per month). At this juncture, I suspect some brands would opt to sit on their hands and milk the ‘cash cow’, but thankfully Grand Seiko does not subscribe to this philosophy.
With the advent of the U.F.A. movement, Grand Seiko no longer talks in days, weeks or months; it now expresses precision in years. And yet, I suspect there is a team in Shinshu currently looking at the U.F.A. movement and thinking of how it can go further. It is for this reason that I, along with many other GS enthusiasts, love the brand. The question now is, “What will be the next three-letter acronym to adorn a Grand Seiko dial?”
Further reading
https://www.grandseikoboutique.uk/
Technical specification
- Model: Grand Seiko SLGB003 Spring Drive U.F.A.
- Case: high-intensity titanium, diameter 37.0 mm, height 11.4 mm, water resistance 10 ATM (100 m), sapphire crystal to the front and sapphire case back.
- Functions: hours, minutes, centre seconds, date
- Movement: Calibre 9RB2, automatic movement, Spring Drive, power reserve 72 hours
- Bracelet: High-Intensity Titanium bracelet and three-fold clasp with push button release and micro-adjustment feature
- Price: £9,950 (RRP as of 1.4.2025)
- Model: Grand Seiko SLGB001 Spring Drive U.F.A.
- Case: platinum 950, diameter 37.0 mm, height 11.4 mm, water resistance 10 ATM (100 m), sapphire crystal to the front and sapphire case back.
- Functions: hours, minutes, centre seconds, date
- Movement: Calibre 9RB2, automatic movement, Spring Drive, power reserve 72 hours
- Strap: Crocodile strap with three-fold clasp in Platinum 950 (partly 18k white gold) with push button release
- Price: £35,500 (RRP as of 1.4.2025)
- Limited Edition: 80 pieces worldwide – sold exclusively in Grand Seiko boutiques
