Grand Seiko Spring Drive Snowflake Special 18k Yellow Gold SBGA090

For our second installment of reviews on the Grand Seiko 18 gold Snowflakes, we introduce the yellow gold variation, SBGA090. As I mentioned in yesterdays review of the white gold SBGA089, this piece is a limited production model that pays tribute to one of the best selling styles of Grand Seiko, the SBGA011.

The dial for the SBGA090 is just like the dial found on SBGA011, replicating the snowfall in Suwa, where Seiko manufactures their Spring Drive movements. This 18k yellow gold model adds yellow gold to the hands and indexes, as well as the SEIKO and GS logo, and the 72 hour power reserve indicator. The hands and indexes are diamond cut at multiple angles, brought to razor sharp edges and finished in the Zaratsu katana blade polishing technique making light reflect at every angle. These little glimmers of light make for easy legibility in low light settings.

The case width is only 39mm (which is slightly smaller than the SBGA011 at 41mm). The case is also finished in the blade polishing technique, which is only entrusted in a small amount of craftsmen. This hand applied finish is done by pressing the case gently against a rotating tin plate over and over again at specific angles until the case has reached its mirror like finish. It takes tremendous experience and skill to achieve this distortion free finish.

In our previous review of the white gold we discussed Yoshikazu Akahane and the near 30 years it took him to develope Seiko’s Spring Drive movement. Today, the discussion lies more in how it actually works. First, Spring Drive is solely powered by the mainspring, as with any other mechanical watch. The power from the mainspring (Seiko’s proprietary alloy Spron 510), drives not only the movement of the hands, but also a very small amount is used to propel a magnetic rotor. This provides the electricity to power what Seiko calls a Tri-Synchro Regulator.

The Tri-Synchro Regulator replaces the traditional escapement found in mechanical watches. Instead of the balance wheel bouncing back and forth on a sensitive hairspring, Seiko has a glide wheel that rotates in one direction. This is what allows the unbelievably smooth gliding motion of Spring Drives second hand as well as relieving tremendous stress on the movement. The electricity from the magnetic rotor powers an integrated circuit and high quality quartz crystal. The frequency from the crystal is transferred through the IC tells an electromagnetic brake to allow the glide wheel 8 rotations per second. This is what allows for the quartz like precision in a mechanically powered watch.

For the 18k Special Edition Snowflakes, the quartz crystal utilized is very unique. After extensive testing and aging, only a small amount of crystals are qualified to go into the special 9R15 movement utilized. These crystals give the 9R15 an astonishing +/- 10 second a month accuracy rating. This is symbolized in the 18k gold medallion on the rotor. Spring Drive already has the highest accuracy rating for a spring powered watch, and apparently, only Seiko can out do themselves.

Only one of each color (white, yellow and pink gold) came to the US market, and are exclusively sold at AZFT. The SBGA090 is $18,000 MSRP. If you have any questions, please call us at 1-800-486-3996 or submit an inquiry through AZFineTime.com.