Grand Seiko SLGH021G Genbi Valley Watch Review
The Grand Seiko SLGH021G Genbi Valley has just been released at Watches & Wonders 2024, a timepiece sporting a nature-themed dial that’s housed in a 40mm ‘Ever-Brilliant Steel’ case and fitted with the Calibre 9SA5 automatic movement. Angus Davies, a self-confessed GS devotee, looks closely at this latest addition to the brand’s Evolution 9 Collection, highlighting the new model’s many attributes and characteristics along the way.
Grand Seiko – dials inspired by nature
Grand Seiko deserves to be acknowledged by Japan’s travel industry for promoting the beauty of the nation’s landscape. Over the years, Grand Seiko has introduced watch obsessives to the beauty of Mount Iwate, snow-clad Shinshu, cherry blossom, silver birch trees, and various other aspects of nature indigenous to the brand’s home nation.
Image – Grand Seiko SBGH341G Sakura-Kakushi
At Watches & Wonders 2024, the Japanese marque unveiled the Grand Seiko SLGH021G Genbi Valley, a new model fitted with a textured dial inspired by a rocky gorge, located in Ichinoseki at the southernmost tip of Iwate Prefecture. Approximately 2km in length, the Genbi Valley is characterised by its rocky landscape that’s bisected by a fast-flowing river. In particular, the lush vegetation of this beauty spot adds a becoming green tint to the vista, a colour faithfully replicated with the new SLGH021G.
Although this is not the first time that Grand Seiko has created a Genbi Valley model, previous references have featured a different dial pattern and been specific to a particular market. For example, the SBGW273, SBGW275 and SBGW277 were limited editions exclusive to the US market. On this occasion, the new Grand Seiko SLGH021G Genbi Valley is available worldwide and subscribes to the Evolution 9 style first unveiled in 2020.
Heritage Collection
In 1967, Grand Seiko unveiled the legendary 44GS, a design that has remained untouched by the fickleness of fashion and now belongs to the brand’s present-day Heritage Collection. Adhering to the company’s founding objectives of legibility and beauty (as well as accuracy), the 44GS encompassed ‘three guiding principles’. These principles relate to the use of flat and two-dimensional surfaces, making the flat surfaces as wide as possible and, lastly, ensuring that each surface exhibits a distortion-free, mirror-like appearance.
Evolution 9 Collection
Fast forward to 2020, Grand Seiko was celebrating its 60th anniversary, a milestone it marked with the release of the SLGH002, a limited edition model housed in an 18-carat yellow gold case. This model was equipped with a new movement, the Calibre 9SA5 (see later) and embraced a new design language, the ‘Evolution 9 style’.
From the outset, the Evolution 9 style was not intended to be revolutionary but rather, as its name suggests, an evolution of what had gone before. Indeed, many characteristics found on the 44GS classic were carried over to this new expression of GS design. However, bearing in mind that Japan is the home to kaizen, the philosophy of continuous improvement, it was perhaps inevitable that Grand Seiko would seek ways to enhance the appearance, legibility and wearer comfort of its products. Several features found on the 44GS have been retained, some elements are ‘evolutions’ of former design details and other aesthetic codes are wholly new. This complement of design characteristics, a total of nine, is reflected in the name of Evolution 9 Collection.
As I explore the housing of the new Grand Seiko SLGH021G Genbi Valley, I will point out those characteristics which distinguish the model as a member of the Evolution 9 Collection.
Grand Seiko Ever-Brilliant Steel
Stainless steel is an alloy of different elements. For example, the chemical composition of 316L includes chromium (16.5 – 18.5%), nickel (10-13%), molybdenum (2-2.5%), manganese (≤ 2%) as well as traces of silicon, nitrogen, phosphorus, carbon and sulphur.
In the European watch industry, the two most common grades of stainless steel used for making cases and metal bracelets are 316L and 904L. The latter grade of stainless steel contains a greater amount of chromium and molybendum and, as a result, has superior corrosion resistance and exhibits a brighter appearance.
The SLGH021G is housed in a case formed of ‘Ever-Brilliant Steel’, a premium stainless steel found on some, but not all GS models. Grand Seiko states that this particular alloy ‘has such high levels of durability and corrosion resistance that it is perfectly suited to use in wristwatches….’.
According to Grand Seiko, ‘Ever-Brilliant Steel’ exhibits ‘a bright white hue and is among the most corrosion resistant types of steel’. A drawback of using Ever-Brilliant Steel is that it is very difficult to polish; however, Grand Seiko, a brand known for its legendary zaratsu polishing technique, has surmounted this obstacle, delivering an ultra-refined blend of mirror polished and hairline finished surfaces.
Grand Seiko SLGH021G Genbi Valley case
Measuring 40 mm in diameter with a case thickness of 11.7 mm, the restrained dimensions of the Grand Seiko SLGH021G Genbi Valley should suit most wrist sizes. Moreover, the case has been endowed with a low centre of gravity (an element of the Evolution 9 style), ensuring the watch sits comfortably upon the wrist.
The flat upper surfaces of the case, along with the curved sides, feature a hairline finish, while the bevelled edges adjacent the caseband are executed in a ‘distortion-free flat mirror finish’. This marriage of contrasting burnishes imbues the watch with a seemly dose of luxury. Both the curved caseband and the contrasting finishes are, once again, elements of the Evolution 9 style.
The sublime ergonomic relationship between the watch and its wearer is something that will be familiar to many GS devotees. With the advent of the Evolution 9 style, Grand Seiko optimised wearer comfort with two additional elements. Firstly, the distance between the lugs is 22 mm, representing over 50% of the overall case diameter (40mm); a characteristic that ensures the watch fits securely to the wrist without undue lateral motion. Secondly, the Japanese marque has optimised the thickness of the bracelet to ensure it remains stable at all times, again heightening wearer comfort. The bracelet is fitted with a three-fold clasp featuring a push button release.
To the rear of the watch, a pane of sapphire crystal affords sight of the mechanical automatic movement, the Calibre 9SA5. Once the watch is removed from the wrist, the dorsal glazing allows the wearer to view many of the mechanical components in motion and also proffers views of the impressive movement finishing.
Grand Seiko SLGH021G Genbi Valley dial
The dial sits beneath a box sapphire crystal, a form of glazing that drinks in light, aiding readability. Grand Seiko has equipped the SLGH021G with a flat dial, a historical GS detail that is also part of the modern Evolution 9 style. Consistent with the aforementioned SLGH002, the hour and minute hands are facetted and resemble the dauphine-style that is popular with European watch companies. However, on this occasion, the hour hand (another EV9 element) has a truncated tip and a recessed line running along its gleaming form, differentiating it from the minute hand.
The elongated minute hand almost kisses the minute track fringing the dial, a design that has been optimised for readability (EV9 element). Each hour marker is facetted and incorporates a deep groove at its centre, while the index at 12 o’clock is double-width and incorporates two deep grooves (EV9 element).
A date display resides at 3 o’clock. Framed with facetted brightwork, black numerals sit atop a white backdrop. Upholding GS tradition, the typography used for the date has been optimised, imparting meaning in lucid form. A lithe centre seconds hand, executed in cornflower blue, completes the inventory of functions.
Inspired by the Genbi Valley, the dial is executed in a distinctive green hue and enriched with a granular texture. The brand’s imaginative use of colours and dial motifs has led legions of horophiles to visit GS boutiques, appreciative of the firm’s unique style of expression.
Grand Seiko movement expertise
Over the years, Grand Seiko has repeatedly shown its expertise in crafting movements. A leading name in quartz movements and the inventors of Spring Drive (a hybrid system, exclusive to the brand) it is also known for producing highly precise mechanical calibres.
The Japanese firm has made hand-wound and automatic 4Hz movements which employ a Swiss lever escapement to ‘control the flow of time’. More unusually, Grand Seiko has also crafted 5Hz movements (eg Calibre 9S85), again fitted with a Swiss lever escapement. Such high-frequency movements are the preserve of only a few brands.
Image – Grand Seiko Calibre 9S85
The benefit of a watch with a high-frequency movement is that it is less susceptible to shocks and positional influence, two factors which can impair precision. However, when creating this type of movement, there are several technical obstacles that need to be surmounted. Firstly, by increasing the balance’s cadence, a high-frequency movement has a tendency to consume more energy, something evident with a limited power-reserve. Furthermore, high-frequency movements are more susceptible to wear and have a tendency to quaff essential lubricants.
With the release of the Calibre 9S85 in 2009, a 5Hz movement (36,000 vph), Grand Seiko addressed said drawbacks. It achieved this feat by employing MEMS technology, a lithographic method of ‘growing’ intricately shaped parts to infinitesimal tolerances. The resultant escape wheel and pallet lever were incredibly smooth, mitigating friction, thereby reducing wear and energy consumption. These parts were also openworked, mitigating mass, again reducing energy consumption. The escape wheel was an elaborate design made possible by using MEMS that incorporated small reservoirs in the end of the wheel’s teeth, holding on to lubricant more efficiently, again mitigating wear and energy consumption.
Image – Grand Seiko escape wheel and pallet fork made using MEMS (Calibre 9S85)
Inevitably, such innovation may prompt questions about longterm reliability; however, the Calibre 9S85 has an impressive track record for dependability and still features in several GS models today.
Grand Seiko Calibre 9SA5
The Calibre 9SA5 was unveiled in 2020 with the advent of the previously mentioned SLGH002. Again, the movement had a high cadence of 5Hz; however, most notably it set aside the Swiss lever escapement in favour of a ‘dual impulse’ escapement.
With a Swiss lever escapement, the escape wheel impulses the balance via the pallet lever. The action of the escapement locking and unlocking causes the hands of the watch to advance a precise amount, often termed ‘controlling the flow of time’. Although the Swiss lever escapement is unquestionably reliable it’s not very efficient due to frictional losses.
The characteristic swinging of the balance, to and fro, typical of a Swiss lever escapement, is also a trait seen with the dual impulse escapement.
In common with a Swiss lever escapement, the dual impulse escapement serves the balance with an indirect impulse when rotating in one direction. However, when the balance rotates in the opposite direction, it receives a direct impulse, a characteristic that differentiates it from the Swiss lever escapement.
The dual impulse escapement has an extra pallet fitted to the balance, circumventing the pallet fork when the balance wheel rotates in one direction. By adopting this highly efficient approach, as well as incorporating twin barrels (see later), Grand Seiko has been able to increase the power-reserve of the movement to 80 hours. It is worth mentioning that the Calibre 9SA5 also incorporates MEMS technology.
Twin barrels serve the gear train and ultimately the escapement with sufficient energy to move the large balance. The barrels are arranged side by side and the horizontal gear train is notably flat, two factors that help mitigate movement thickness. This allows GS to create a slimmer case with a lower centre of gravity that hugs the wrist more comfortably.
Most mechanical watches are fitted with an index-regulated balance, where the effective length of the hairspring is adjusted to make the watch run faster or slower. The Calibre 9SA5 is equipped with a free-sprung balance, a system which is technically superior. With a free-sprung balance, also known as a variable-inertia balance, the effective length of the hairspring is fixed and the rate is altered by adjusting timing weights positioned on the rim of the balance wheel (not to be confused with poising weights). This system facilitates more precise regulation of the watch. Furthermore, should the timepiece be subjected to a shock, it is less likely to require remedial regulation.
In this instance, Grand Seiko has positioned the inertia weights in recesses within the rim of the balance wheel, mitigating air turbulence and thereby aiding precision. The Calibre 9SA5 also features an overcoil, a refinement which enhances the ‘development’ of the balance spring (the way it breathes), improving both precision and stability.
Upholding Grand Seiko’s penchant for nature, the movement architecture has been inspired by the ‘shape of Mt. Iwate and a bend in the nearby Shizukuishi River that runs past the studio where the watch is made’. Grand Seiko has not only referenced its home, but also endued the movement with a plethora of refined finishes. The curved bridges are adorned with a striped motif, the mainplate is embellished with perlage and blued screws abound. Upholding its fondness for juxtaposing light and shadow, Grand Seiko has endowed the sides of the movement with a matte finish while executing the ‘ridges, edges and screw holes’ with a brilliant finish. The resultant appearance of the Calibre 9SA5 will undoubtedly engender smiles of appreciation among the watch collecting fraternity.
Grand Seiko SLGH021G Genbi Valley – closing remarks
Grand Seiko has always chosen its own course to greatness, often rejecting the well-trodden path taken by many of its European counterparts. The SLGH021G Genbi Valley upholds this tradition, uniting a bewitching green dial, ergonomic case design and a remarkable movement.
The Calibre 9SA5, a ‘Hi-Beat’ movement, proffers superior 5Hz precision while sidestepping the usual drawbacks associated with high-frequency calibres. As well as capitalising on the lightweight properties afforded by MEMS technology, the decision to opt for a dual-impulse escapement has also mitigated energy consumption, culminating in an impressive power reserve of 80 hours. Various additional refinements such as the free-sprung balance and, most notably, the overcoil, contribute to the impressive stated accuracy of ‘+5 to -3 seconds per day’.
Back in 1960, the brand’s goal was to create ‘an accurate, legible and beautiful watch’. As many admirers of Grand Seiko will attest, the firm has fulfilled this objective many times and with the advent of the SLGH021G Genbi Valley it has done so again.
Further reading
https://www.grandseikoboutique.co.uk/
Technical specifications
- Model: Grand Seiko SLGH021G Genbi Valley
- Case: Ever brilliant steel, diameter 40 mm, height 11.7 mm, water resistance 10 ATM (100 metres), box-shaped sapphire crystal to front, sapphire caseback.
- Functions: hours, minutes, centre seconds, date
- Movement: Caliber 9SA5, self-winding movement, frequency 36,000 vph (5 Hz), 47 jewels, power reserve 80 hours.
- Strap: Ever brilliant steel bracelet with 3-fold clasp with push button release.
- Price: £9,750 including VAT (RRP as of 9.4.2024)
- Limited Edition: 1000 pieces (on sale from June 2024)