Imagen: Grand Seiko, web oficial
The storyWhy this reference matters
In 2019, for the Spring Drive's twentieth anniversary, Grand Seiko introduced two new hand-wound calibres: the 9R02 and the 9R31. Until then almost every Spring Drive in the house was automatic and wore its power reserve indicator biting a chunk out of the dial. The 9R31 did the opposite: it sent the indicator to the back, slimmed down, and became the thinnest Spring Drive to come out of the Shinshu Watch Studio. This particular dial arrived in July 2021.
Lake Suwa, in Nagano, is a short hop from that workshop. Every winter it freezes over, and hot springs on the bed push up until the surface cracks and a ridge of ice rises shore to shore. Shinto tradition calls it omiwatari: the path the gods take. The SBGY007 dial copies that broken ice, its mould hammered by hand for texture and given a gentle curve.
Spring Drive has no escapement and no balance wheel. The mainspring drives the going train and, at the end of the run, a glide wheel that an electromagnetic brake holds in check, comparing its speed against a quartz reference. Two things come out of that: ±1 second a day of deviation, and a seconds hand that genuinely sweeps, without the faintest twitch. The 9R31 fits two mainsprings in a single barrel to reach 72 hours, on 30 jewels.
SpecificationsThe numbers, in one table
| Brand | Grand Seiko |
|---|---|
| Family | Elegance |
| Reference | SBGY007 |
| Years made | desde 2021 |
| Calibre | Grand Seiko 9R31 |
| Movement | Spring Drive |
| Power reserve | Aprox. 72 horas |
| Jewels | 30 |
| Complications | Indicador de reserva de marcha (en el fondo) |
| Diameter | 38.5 mm |
| Thickness | 10.2 mm |
| Lug to lug | 43.7 mm |
| Lug width | 19 mm |
| Case | Acero inoxidable |
| Crystal | Zafiro de doble curvatura con tratamiento antirreflejos |
| Water resistance | Resistente a salpicaduras de uso diario (no sumergible) |
IdentificationHow to tell it apart
No date and no power reserve on the dial: hours, minutes and that thermally blued seconds hand, and nothing else. The reserve sits round the back, on the display case back, and it's the quickest way to tell a hand-wound Spring Drive from the automatic 9R65s, which carry theirs on the front at eight.
The case measures 38.5 mm across, 43.7 lug to lug and 10.2 thick, with 19 mm lugs. No screw-down crown, and splash resistance only: this isn't a sports watch in a suit, it's a genuine dress watch. The crystal is dual-curved sapphire, which is why the reflection rounds off at the edges.
The dial texture isn't a regular engraving: these are cracks and plates of uneven size in an ice blue that goes very pale in direct light. Look at it from the side. If the relief looks printed or repeated, something is wrong.
CollectingWhat collectors check
Service is the critical point. A Spring Drive contains an integrated circuit, a coil and a glide wheel; the watchmaker round the corner will not open it. Ask whether the watch has been through official service, and when. Check as well that the seconds hand glides without the slightest tremor: any tug or vibration is a bad sign.
With no date and virtually no water resistance, condition rests entirely on the outside. Crystal, lug edges and mirror-polished flanks — that's where a visit to the polishing wheel shows up immediately. And the dial, which cannot be restored; a spot of corrosion or a mark in the relief is permanent.
It sold on a crocodile strap with the brand's folding clasp. Swapping a 19 mm strap is easy, but the original clasp adds value, so make sure it comes with the watch. Box, papers and warranty complete the package.
Common questionsWhat people ask us about this reference
Does a Spring Drive have a battery?
No. It's mechanical: the mainspring runs the watch and also generates the current that feeds the quartz regulating it. If it stops, you wind it and it goes again.
Can the SBGY007 get wet?
Splashes only. Grand Seiko doesn't rate it for immersion, so no shower, no pool, no sea.
How much reserve does it have, and where do you read it?
Seventy-two hours, thanks to two mainsprings mounted in the same barrel. The indicator is on the back, so you have to turn the watch over to see it.
What does omiwatari mean?
It's the name of the ice ridge that forms when Lake Suwa freezes over. Shinto tradition holds that the gods open it as they cross the lake shore to shore.
Keep readingWhere to go from here
Close relativesThe ones it gets confused with
Confidence: alta — this page was checked against the sources below. If a detail looks wrong to you, write to us and we will fix it.