Masamasa Hirota, editor-in-chief of Chronos Japan, also known as "Watch Professor," will be publishing five columns on webChronos about masterpiece movements written in 2024. The first column will be about the new manual-winding movement, "Cal. 9SA4," released by Grand Seiko in the same year.
[Article featured in Movement Book 2024]
The "Cal.9SA4" is not just high-performance, it also offers emotional value.
The Caliber 9SA5 automatic movement raised the bar for Grand Seiko. No other mechanical movement combines a high vibration frequency of 36,000 vph with a long power reserve of approximately 80 hours. Furthermore, this movement incorporated various new mechanisms to improve precision. For example, the Grand Seiko Free Spring movement, which does not have a regulator. While other manufacturers use a screw on the balance wheel to adjust the delay/gain, this movement allows for precision adjustment by deforming the outer end of the winding balance spring. This overturns the conventional wisdom in the watch industry that the winding balance spring cannot be tampered with. The escapement also features a dual impulse escapement, completely different from the Swiss lever escapement. While similar to a coaxial escapement, it differs in that it prioritizes the free oscillation of the balance spring, while the new escapement pursues overall escapement efficiency. With specifications unusual for a mass-produced watch, it's no surprise that the Caliber 9SA5 has garnered worldwide acclaim.
The manual-winding Cal. 9SA4 was created based on this movement. While it is standard practice in the watch industry to create a manual-winding movement based on an excellent automatic movement, Grand Seiko has apparently created approximately 40% of its parts from scratch. The aim was not simply to create a thin movement, but to give it an excellent feel. The key to providing that feel has been redesigned to be much stronger, and it now also moves horizontally, allowing it to be turned with less force.
In addition, to improve the feel of the crown, the crown gasket was tuned and the size of the crown itself was also revised. These small revisions have made the winding feel of the Cal. 9SA4 feel different from that of a mass-produced watch. There are other aspects of the feel that have been pursued as well. For example, the weight of setting the hands. As you'd expect from a high-end watch, it feels smooth and there is no loss of movement even when turned counterclockwise.
To be honest, it's unclear how far this pursuit of tactile sensation will reach consumers. However, discerning watch lovers will surely be amazed not only by its high performance, but also by the ease of winding the crown, which is unusual for a current model, and the smoothness of the hand setting. In addition to the high performance inherited from the Cal. 9SA5, the Cal. 9SA4 also emphasizes the emotional value of tactile sensation. While it may look unassuming at first glance, this is a masterpiece that represents today's luxury watches.
