Grand Seiko Evolution 9 "Birch Bark" Hi-Beats hand-wound white dial leather strap 38,6 mm

Manual winding: a daily pleasure

Winding a movement is a ritual that is part of our daily pleasures. The simple act of turning the crown reconnects us with the natural flow of time. In the 1960s and 1970s, Grand Seiko's hand-wound, 10-alternations-per-second creations were designed in a quest for stability and precision. This year, for the first time in over 50 years, Grand Seiko announces a new high-frequency hand-wound movement, the caliber 9SA4. This is the third movement making up the new generation of the mechanical caliber 9S, which saw the light of day in 2020 with the automatic caliber 9SA5, followed in 2023 by the Tentagraph chronograph, powered for its part by the caliber 9SC5.

An entirely redesigned movement based on Calibre 9SA5

Like Calibre 9SA5, the new 9SA4 beats at a frequency of 10 vibrations per second. Fully wound, it offers an 80-hour power reserve thanks to its double impulse escapement and twin barrels. Both movements incorporate Grand Seiko's racketless balance and end-curve balance-spring, giving them great stability, increased resistance to external interference and the performance for which Grand Seiko Hi-Beat 36000 movements are renowned. Like other Grand Seiko mechanical movements, the 9SA4 is tested in six positions for 17 days, at three different temperatures, to verify its compliance with the Grand Seiko Standard.

Although the new caliber 9SA4 shares many features with the 9SA5, almost 40 percent of the basic movement has been redesigned and rebuilt with particular attention to the tactile, sonic and visual sensations of winding. The movement's pawl, the part that holds the ratchet to prevent the spring from unwinding, and its spring have been adapted to perfect the watch's ergonomics and acoustics and enable the crown to be locked once the movement is fully wound.

The pawl is shaped like a wagtail, the emblematic bird of the town of Morioka, near the Grand Seiko Studio Shizukuishi where all Grand Seiko mechanical watches are produced. The movement has been redesigned to make it visible through the sapphire caseback during winding, imitating the bird's beak. Sublimated by delicate finishes inspired by the Shizukuishi River, the caliber 9SA4 synthesizes Grand Seiko's horological know-how and expertise, while capturing the beauty of the Studio's environment.

The movement achieves greater winding efficiency thanks to a rearrangement of the gear train and a new parts design. For example, winding the caliber 9SA4, observable via the reserve indicator on one of the bridges, requires 15% fewer crown rotations than the caliber 9SA5. Thanks to the finesse of its movement, this birch-inspired mechanical watch measures just 38.6mm in diameter for a thickness of 9.95mm.

An elegant watch in the Evolution 9 style

The Calibre 9SA4 will make its debut in the Evolution 9 collection, whose aesthetics continue the Grand Seiko style inaugurated in 1967 with the iconic 44GS. With this timepiece, the Evolution 9 style has been perfected to give birth to a watch expressing the charm, elegance, grace and subtlety expected of a hand-wound watch.

Many aspects of the watch's design have been revisited: the protruding, grooved hour markers have been refined and lengthened, while the multi-faceted lugs are now narrower and have a reduced surface area. The watch's center of gravity has been lowered to ensure the comfort and stability for which Grand Seiko's Evolution 9 style is renowned.

The case and bracelet are made of Brilliant Hard Titanium. Emblematic of Grand Seiko, this alloy is brighter than traditional titanium. Its surfaces have benefited from Zaratsu polishing to give them even more lustre and bring out the beauty of the metal. Brilliant Hard Titanium makes the watch lighter, but also highly resistant to corrosion and scratches, while offering twice the hardness of standard stainless steel.

A dial in tribute to the beauty of nature

The dial of this new creation is inspired by the slender white birch trees typical of northern Japan, which profile in the vicinity of the Grand Seiko Studio Shizukuishi where all Grand Seiko mechanical watches are produced. Its delicate pattern echoes the beauty of birch bark and its complex, multi-dimensional texture. Thanks to its elegance and the high precision of its movement, this new creation offers a refined experience of the nature of time.