Easily one of the biggest highlights of the fair from a personal perspective are the new Grand Seiko SLGW002, an 80-piece limited edition in rose gold and the SLGW003 in titanium. These watches mark the introduction of the new 9SA4 caliber, the brand’s first hand-wound hi-beat movement in more than 50 years.

Grand Seiko has diversified its collections and scaled upmarket in a fairly short time with the Masterpiece Collection and more recently the Evolution 9 Collection. In the past three years alone, it brought to market the enormously impressive Kodo Constant-Force Tourbillon, a tourbillon with a co-axially integrated remontoir. It also developed a superb high-performance automatic movement, the 9SA5, which debuted for the first time in over two decades a brand-new escapement for industrial production. And last year, it introduced the Tentagraph, its first ever mechanical chronograph.

The 9SA4 inherits all of the same attributes that made the 9SA5 extraordinary. It is one of the few industrially produced movements on the market that delivers both a long power reserve (80 hours) and a high frequency (36,000 vph), thanks to a more efficient escapement. The escapement is simply called the Dual Impulse escapement, which seems rather arid as apart from the detent escapement, all wristwatch escapements today fall under the category of dual impulse escapements, including the Swiss lever. This refers to their ability to deliver two impulses, each in opposite direction, to the balance wheel at each cycle — one at each semi-oscillation. Such a feature is crucial in the development of a modern, practical escapement capable of withstanding external perturbations in a wristwatch.

Grand Seiko’s Dual Impulse escapement is only the second non-Swiss-lever escapement that has been successfully brought to an industrial reality after the Co-Axial. With modern manufacturing techniques and materials, the traditional Swiss lever escapement has seen remarkable developments, with prime examples being the Rolex Chronergy and the Patek Philippe Pulsomax. However, the inherent challenges in attempting to design a brand-new watch escapement, let alone one that can eclipse and replace the lever, have made such an accomplishment a standalone complication in its own right, and one considerably rarer.

Notably, the new watches measure just 38.6mm wide and 9.95mm in height when cased up, compared to the 40mm by 11.7mm dimensions of their automatic counterparts. They are far more elegant and everything one would expect from a modern, thoughtful dress watch. As context, I’ve owned the 9SA5-equipped SLGH013 with a 44GS case for about a year now and it’s been nothing short of satisfying on every front. It’s one of those watches that is so relentlessly complete in aesthetics and mechanics that it seems to provide an experience nothing else offers. However, specifically on my 5.4-inch wrist, its proportions dominate with a grandiosity that is hard to ignore even though it is slimmer than many other Grand Seiko watches.

According to Grand Seiko, arriving at the 9SA4 took more than just removing the self-winding system of the 9SA5; approximately 40% of components had to be reworked. Furthermore, the new 9SA4 does away with a date function and includes a power reserve indicator on the bridge side. Most notably, the movement was designed with a more tactile, aural, and visual winding experience in mind.

The Case & Dial

The 9SA5 movement has been housed in two distinct case designs: the historical 44GS case, exclusive to the SLGH013 in the Heritage Collection, and a modern, streamlined interpretation inspired by the 44GS, utilised in all models within the Evolution 9 Collection, including the SLGH005 White Birch and the titanium SLGH017. The case of the SLGW002 and SLGW003 is a further refinement of this modern design. The lugs are slimmer with smaller facets, which helps sets the stage for the dial. The top surfaces and flanks are satin-brushed and are delineated by a slim but pronounced polished bevel. The bezel has two distinct upper and lower bevels that are polished and brushed as well.

The regular-production SLGW003 is executed in Brilliant Hard Titanium, a proprietary alloy that is almost twice as hard as stainless steel and is said to be highly resistant to corrosion and scratches. While titanium is a rather unusual metal for a dress watch, the alloy has a significantly brighter appearance compared to standard titanium. As such, the watch could easily be mistaken for polished steel, given the difficulty of polishing titanium. The lighter hue further enhances the shine of Zaratsu-polished surfaces, ensuring that even though the facets are relatively subtle, they remain distinctly visible.

In contrast to the 100m water resistance of the automatic SLGH counterparts, it does not have a screw-down crown and is depth rated to 30m, which appears to be the standard for the majority of non-44GS dress watches all the way up to the SBGZ009. The dial texture is once again inspired by the white birch trees enveloping the Grand Seiko Studio Shizukuishi in northern Japan. However, this time it is executed horizontally, and the pattern is notably softer in appearance, offering a more subdued effect compared to the harsh vertical motif found in the SLGH005. It completes the impeccably executed dial, where diamond polished dauphine hands and grooved and faceted diamond polished indexes stand in dignified elegance, without overwhelming it.

The rose gold SLGW002 features a star motif right above the six o’clock marker, signifying that its indexes are crafted in gold. On the wrist, the dial is striking and it’s hard not to be stirred by its beauty, even for those well-adjusted to the exceptional quality of Grand Seiko dials. The only caveat, if one could call it that, is that the larger, more defined ridges render the pattern more noticeably identical on each piece. In contrast, the SLGH005 displays a denser, less distinct vertical pattern that, while also uniform across every piece, is less conspicuous. Nevertheless, a timepiece of this caliber is inherently unique and distinct within the broader context of industrial luxury watchmaking and its excellence speaks for itself.

The Hand-wound 9SA4

The 9SA4 shares the same diameter as the 9SA5 at 31mm wide but boasts a slimmer profile, measuring 4.15mm in thickness compared to the 5.18mm of the latter. According to the Grand Seiko, the 9SA4 requires 15 percent fewer crown rotations to achieve full wind as compared to the 9SA5 when wound by hand. Like the 9SA5, the movement is equipped with double barrels arranged in a serial configuration where the first barrel drives the second directly without an intermediate wheel. The first ratchet wheel is noticeably smaller than the second, which is covered by the main bridge. This makes room for an elaborate winding click as well as the first wheel in the gear train that forms part of the power reserve mechanism.

The winding click, along with its spring, is a rather simple mechanism. It acts as a ratchet that allows the mainspring barrel to rotate in only one direction during winding and prevents the mainspring from unwinding backward when winding is complete. This ensures that the energy stored in the mainspring is retained and transferred to power the gear train. It is commonly found in the shape of a beak or as a cam with two tips as in the 9SA5. The click held in tension by a spring that keeps it engaged with the ratchet wheel during winding and also serves to return the winding click to its resting position when winding is complete.

This action produces the characteristic clicking sound as the winding click moves against the teeth of the ratchet wheel. The mechanism typically does its job without drawing attention to itself. However, in the 9SA4, winding click takes the shape of a wagtail, a bird with special significance to Morioka, a city close to the Grand Seiko Studio Shizukuishi. A long, curved click spring that is thicker at its end forces the beak of the wagtail against the ratchet wheel. Their unique design produces a distinct clicking sound, providing a more distinct and satisfying aural and tactile feedback during the winding process.

As with the 9SA5, the 9SA4 has a horizontal gear train layout. The gear train consists of five wheels instead of three as the escape wheel has fewer teeth. As such, it is the fifth wheel that drives the centrals seconds directly. Rather than increasing the number of teeth on the escape wheel to achieve a higher beat, two additional wheels were added to distribute the load across more wheels, mitigating wear on the pivots and wheels.

At the heart of the movement is the Dual Impulse escapement. It is self-starting and provides two impulses per cycle — one in each direction — making it resistant to shocks. While the Swiss lever escapement provides two impulses indirectly via a lever, the Dual Impulse escapement, like the Co-Axial, adopts a mixed impulse system: one impulse is given directly to the balance wheel, while the other is delivered indirectly via a lever. It essentially combines the solidity of the Swiss lever’s locking and unlocking system with the direct impulse action of the detent escapement. As a result, the escapement operates much more efficiently than the lever and provides greater long-term rate stability.

The pallet fork and lever are produced using LIGA, allowing components to be fabricated with extreme precision, resulting in its intricate, skeletonized geometries that are lighter to ensure quicker acceleration of parts, which is crucial in a high beat movement. Additionally, the balance wheel is free sprung, secured on both ends by a balance bridge for greater stability, and is attached to an overcoil hairspring with a proprietary curve.

Beyond that, the shapes of the bridges are visually attractive and exhibits a natural and logical arrangement that accentuates the prominence of the winding click and balance wheel. The finishing, as always, is exceedingly clean and attractive. It is decorated with perlage on its base plate, striping on its bridges which even continues unto the balance bridge, polished countersinks as well as mechanically applied anglage. The limited edition rose gold SLGW002 commands a considerable premium at US$45,000, while the titanium SLGW003 is priced at US$10,700, which, although more expensive than the 9SA5-equipped models, still offers great value given its exceptional technical qualities, for which there is no equal in its price bracket and even beyond.

Tech Specs

Movement: 9SA4 manually wound; 80-hour power reserve; 5Hz high-beat
Functions: Hours, minutes, seconds
Case: 38.6mm x 9.95mm; titanium; rose gold; 30m water resistance
Availability: Titanium is not limited; rose gold variant is a limited edition of 80
Price: USD 10,700 (titanium); 45,000 (rose gold)

Find out more at Grand Seiko.