Grand Seiko has introduced the Evolution 9 “Birch Bark” SLGW002 and SLGW003, in rose gold and “brilliant hard titanium” respectively. Named after the dial pattern, the “Birch Bark” is powered by a new manually-wound, high-beat caliber that features the brand’s proprietary dual-impulse escapement.

The only completely new model introduced by Grand Seiko at Watches & Wonder this year, the new references introduce a new, notably slimmer aesthetic to the brand’s Evolution 9 collection. 

Initial thoughts

Grand Seiko has earned a devoted following in recent years, but collectors have been asking for slimmer options for some time; this release proves the brand is listening. While there’s nothing revolutionary about it, the watch has been nipped and tucked in all the right areas, getting the case down to 38.6 mm in diameter and just under 10 mm in thickness. 

Compared to the most similar existing watch in the catalog, the Spring Drive SLGA009 “White Birch” launched two years ago, the new Evolution 9 feature a new movement, a thinner case, slimmer dial markers, and a horizontal interpretation of the brand’s signature white birch-inspired dial texture.

The slimmer profile is made possible thanks to the new 9SA4 movement, which is essentially a 9SA5 without automatic winding. This makes it the first manually wound caliber from Grand Seiko’s latest generation of mechanical movements, and also the first to be available without a date function. Perhaps the only drawback is the reduction in water resistance from 100 m in the thicker automatic models to just 30 m.

Pricing has increased along with these changes, but the titanium SLGW003 still offers reasonably good value at US$10,700 thanks to its interesting movement and high level of execution throughout.

However, the pricing of the rose gold SLGW002 is much harder to justify at nearly US$45,000. Limited to 80 pieces, the gold model also features a solid gold “Special” dial, denoted by a star at the six o’clock position.

A new caliber

While the new 9SA4 movement features the same 5 Hz beat rate and 80-hour power reserve of its automatic sibling, the removal of the automatic system gets the movement down to just 4.15 mm in thickness, which is about 1 mm thinner than the 9SA5.

If that doesn’t seem like much, it’s because the 9SA5 was designed to be quite wide and thin, with the automatic winding train in the same plane as the twin barrels. As a result, eliminating these components does not reduce the thickness, so it really just comes down to the removal of the rotor and the date mechanism on the dial side.

In place of the automatic train, the brand has installed a power reserve indicator which is visible through the sapphire case back. Other changes include a new winding click that has been developed to enhance the winding feel, which feels both pleasant and robust.

Otherwise, the movement largely mirrors the 9SA5 and features the brand’s proprietary dual-impulse escapement powering a free-sprung balance with overcoil hairspring. The finishing is industrially applied, but is nonetheless bright and attractive, with machined anglage and countersinks for the jewels and screw heads.

Key facts and price

Grand Seiko Evolution 9 Manual-Winding Hi-Beat 36000 “Birch Bark”
Ref. SLGW002 (rose gold)
Ref. SLGW003 (titanium)

Diameter: 38.6 mm
Height: 9.95 mm
Material: Titanium or rose gold
Crystal: Sapphire
Water resistance: 30 m

Movement: 9SA4
Functions: Hours, minutes, and seconds
Winding: Manual
Frequency: 36,000 beats per hour (5 Hz)
Power reserve: 80 hours

Strap: Alligator strap with folding clasp

Limited edition: 80 pieces for SLGW002, regular production for SLGW003
Availability: At Grand Seiko boutiques and retailers starting August 2024
Price: US$10,700 (SLGW003); US$45,000 (SLGW002)

For more, visit grand-seiko.com