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Grand Seiko’s First Mechanical Chronograph, The Tentagraph SLGC001 (Live Pics & Price)

Grand Seiko expands its Evolution 9 collection with its first mechanical chronograph, the Tentagraph.

| By Brice Goulard | 6 min read |
Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

While having undebatable watchmaking credentials and a serious portfolio of mechanical watches, Grand Seiko is also known for its unique expertise in the field of hybrid watches, with its proprietary Spring Drive technology. This might explain why, in so many years of existence – the brand was born in 1960 – the only chronographs available from Grand Seiko were powered by the calibres 9R86 and 9R96 – both using the same integrated base with Spring Drive and a very (too) complex display. Things are changing this year, as the Evolution 9 collection expands more and more. Following the first mechanical complication in this range last year – a GMT watch – Grand Seiko now presents its first-ever mechanical chronograph, with the Tentagraph SLGC001.

If it’s clear that the Calibre 9SA5, extensively explained in this article on the successful White Birch, was key in the foundation of the new Evolution 9 collection, what we didn’t know so far is that it was developed to become a vessel for more iterations. And the first one to be revealed is a long-expected movement for Grand Seiko, a mechanical chronograph… something that was surprisingly absent from the brand’s portfolio of movements, despite 60 years of history and watchmaking expertise. We know Grand Seiko is capable of great things, either mechanical or hybrid, and the brand is no stranger to the chronograph. Indeed, as of now, all chronograph watches were powered by the Calibre 9R86 and its evolution, the 9R96 – you can see an example below.

Using the Spring Drive technology, it is an impressive movement with integrated architecture, column wheel and complex (slightly odd) display with GMT function and power reserve indicator. It was presented in 2007 and there’s finally an entirely mechanical counterpart in the collection.

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The New calibre 9SC5

The choice for Grand Seiko’s first mechanical chronograph movement, the calibre 9SC5, is classic in terms of display – tri-compax layout and date indication. What’s more surprising are the choices for the movement. We could have expected an automatic, integrated architecture. But instead, GS chose to use its 9SA5 movement – a very impressive base, if you ask me, technically speaking – and to add a chronograph module on top. Despite strong efforts to erase some of the flaws of such an architecture – no offset pushers, almost no effect on the power reserve – this remains a slightly less noble choice. But, the counterpart comes in the form of a base movement that has unquestionable qualities.

As such, the high-end specs of the 9SA5 remain true for the new Chronograph calibre 9SC5. It means a slim profile for the base, a double-barrel layout for a long and stable power reserve, a 5Hz frequency (or 36,000 vibration/hour), a 72h power reserve (instead of 80h on the 9SA5) and the use of the complex Dual Impulse Escapement (a modern geometry that comes close to the Co-Axial), a free-sprung balance and an accuracy rated for +5 to -3 seconds per day. Finally, the look from the caseback isn’t that of a classic chronograph but remains appealing, nicely designed and finely decorated.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

As for the chronograph function, the module is located on the dial side, thus invisible. The module relies on a vertical clutch and a column wheel, together with a three-pointed hammer. All combined, it ensures precise control of the chrono operation, it eliminates any shuddering or jumping of the hands when the chronograph is engaged and ensures that all hands return to zero instantly and in perfect synchronization. Also, the 72h power reserve is the longest on the market for a 5Hz chronograph. Finally, as said, the pushers and crown are perfectly aligned, not offset as on many modular chronographs. All in all, some choices are surprising, yet the result remains a powerful, ultra-modern movement.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

The Grand Seiko Tentagraph SLGC001

A few words first on the name. Tentagraph results from the specs of the watch; TEN beats per second, Three days power reserve, Automatic chronoGRAPH. Now, while the movement is a bit surprising, the watch to house this brand new calibre is typical Grand Seiko and, for the best, is a strong departure from the previous chronographs offered by the brand. Slimmer, less polarizing, more discreet, and more classic altogether – including the display – it feels like the natural development of the Evolution 9 collection. There’s an immediate connection between the Tentagraph SLGC001 and the Evolution 9 Sport Spring Drive GMT SBGE283 & SBGE285 of last year – and in a slightly less obvious way, with the Evolution 9 Chronograph GMT SBGC249.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

The design of the case, which is here presented in high-intensity titanium (which can be compared to grade 5 titanium) is typical of the Evolution 9 collection and its sports watches. A bit slimmer, more curved, shorter on the wrist and made with ergonimics in mind, it remains in line with the 1960s Grammar of Design, however with a modern twist. The lugs are pointy, most surfaces are brushed and a handsome curved Zaratsu polished bevel runs on the side of the case. Mind you, despite being relatively short on the wrist, the Grand Seiko Tentagraph is still a rather sizeable model, measuring 43.2mm in diameter and 15.3mm in height. But on my small 16.5cm wrist, it remains manageable.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

This reference SLGC001 is, otherwise, quite classic in specifications. It’s a sporty automatic chronograph, with 100m water-resistance, screw-down crown, screwed back with see-through crystal, a box-shaped sapphire crystal on top and a lightweight sensation on the wrist. Two nice features I want to highlight. First, the bezel in black ceramic has a combination of polished and brushed surfaces, adding depth and dynamism, in addition to the engraved tachymeter scale. Second, GS has finally made pushers that are decently sized, and doesn’t use gigantic pushers anymore, like in the Spring Drive chronographs.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

As for the dial, Grand Seiko doesn’t take any risks with its first mechanical chronograph – and I can’t blame them. First of all, the layout is balanced and traditional, with 3-6-9 counters for the small seconds, 30-minute and 12-hour counters. The date at 4:30 is coloured-matched and doesn’t disturb me. The hands and markers are classic for the Evolution 9 collection, bold, ultra-detailed and largely luminous. The colour and texture chosen are again classic GS, with a Mt. Iwate sunray-style pattern and a deep blue colour. As always, the execution of the dial and hands is flawless.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

Matching the case, the Tentagraph SLGC001 is worn on a high-intensity titanium bracelet, with brushed surfaces and polished accents. It is closed by a folding clasp with a push-button release and features a series of holes used as a simplified micro-adjustment system.

Grand Seiko Evolution 9 Tentagraph SLGC001 - First Mechanical Chronograph Grand Seiko review

Availability & Price

The Grand Seiko Evolution 9 Tentagraph SLGC001 will be released as part of the permanent collection and will be available in boutiques and selected retailers in June 2023. It will be priced at EUR 14,300. For more details, please visit

4 responses

  1. Great article thanks Brice, did you manage to get a lug to lug measurement? Or weigh it? I know you mention it fits well on your wrist but I’m worried it would still be huge.

  2. Given the elephantine proportions, the inflated price and the almost one-on-one copied look of Seiko’s “Seitona”, which runs with great accuracy on solar power, I thibk I’ll stick to that one.

  3. @Etfeik Tsooj It’s a sizable watch, but saying that it’s elephantine is an exaggeration. This watch doesn’t look like a Seiko Astron watch at all. Neither does a Seiko Astron look like a Rolex Daytona watch.


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