Grand Seiko Heritage SBGA507 and SBGA509

Quick specs Grand Seiko Heritage SBGA507 and SBGA509
Price: $ 5,600 | approx. € 5.200 | approx. £ 4,400 | approx. CHF 4’900
Size: 40 mm
Reference: SBGA507 (blue) | SBGA509 (pink) – limited to 300 pieces each

Grand Seiko presents two new models, or let’s say colors, for the US market only, with the Grand Seiko Heritage SBGA507 and SBGA509. The 507 is blue, the 509 is pink. And like most Japanese watches, the names sound like a type of washing machine. These are part of the Heritage editions, sub edition 44GS (named after a classic case, we can understand that), called SBGA507 and SBGA509.

These rather passionless names luckily never reflect the watch itself. here the classic looking 40-millimeter stainless steel case bears a dial with a “kirazuri ukiyo-e” woodblock print texture. The colors are inspired by the upcoming daylight, in a pink hue, and the evening sky, in a soft blue, nearby the factory of Grand Seiko’s spring drive movements. “Ukiyo-e” is a Japanese genre of art that includes prints and paintings with vibrant colors, intricate details, and bold compositions.

Kirazuri dial

Kirazuri is a technique within Ukiyo-e that involves the application of mica powder to create a shimmering, glittering effect on the print. Which is all admirable on the dial, that has applied polished facetted steel indexes and hands. And a gold colored applied GS logo on top.

At the 7:30 o’clock position is an arc-shaped power reserve indicator, and at 3 there is a date. The central seconds hand of the blue SBGA507 is blued, the central seconds hand of the pink SBGA509 has a steel color. Now, let’s look at the spring drive movement inside.

What is a spring drive movement?

These Grand Seiko’s have a spring drive movement, an automatic mechanical movement that can be hand-wound as well. Like almost all automatics. However, it has quartz components as well. The name of this type of movement is often called “automatic spring drive”, as the movement is spring driven.

But regular (automatic) mechanical watches are also driven by a spring, sitting in a barrel. So, what are the differences between a regular automatic mechanical movement and an automatic spring drive movement?

Differences between a regular mechanical movement and a spring drive movement

A mechanical movement uses an escapement mechanism and a balance wheel to regulate the release of energy from the mainspring. This is where the characteristic “tick-tock” sound comes from. Factors like temperature, position, and wear over time lead to a daily deviation of a few seconds to several seconds.

Instead of an escapement and balance wheel, the spring drive uses a glide wheel regulated by an electronic speed control mechanism. This includes a quartz crystal, an electromagnetic brake, and a rotor. The so called “tri-synchro regulator”. Due to the electronic regulation the daily deviation is about 1 second. So, a spring drive movement is more precise, often more efficient and less responsive to external influences. The recommended service interval is 2 to 3 years, while a regular high-end automatic can be serviced after 4 to 6 years.

The Grand Seiko Heritage SBGA507 and SBGA509 have a power reserve of 72 hours

Inside both watches is the Grand Seiko caliber 9R65 Spring Drive with a power reserve of 72 hours. Which is indicated at the front of the watch. This caliber 9R65 is rated at a deviation of about 15 seconds per month.

The Grand Seiko Heritage SBGA507 and SBGA509 come on a stainless steel bracelet with three-fold clasp. And both models are limited to 300 pieces, as said only available in the US and only in GS boutiques. Leaving the rest of the world in jealousy. Although there are a lot of SGRBT-something models available in all kinds of other colors in your region as well.