Super Precision Seiko SBGA403 20th Anniversary Edition

Last year we managed to get our hands on one of Grand Seiko’s finest creations in some time, the GS Sport Spring Drive 20th Anniversary Edition. We loved it, and if you want to see exactly why, you can check out our full hands-on review here.

Now that it’s available to buy – specifically at Fraser Hart, with a new twist () we thought we’d take a closer look at what makes the watch even more special than its design: the movement.

A new change shop in Fraser Hart

Firstly, it’s worth mentioning the difference between Seiko and Grand Seiko. In 1960, Grand Seiko was founded with one purpose: to create the perfect luxury watch. They did this by taking Seiko’s technical advances and turning them into true haute horology, with exceptional finishes – such as their now iconic Zaratsu polishing – and timeless designs to match. The Spring Drive movement is a big part of that, too.

The 9R15 calibre is the latest iteration of this extraordinary Spring Drive family, a movement that combines the mechanical power of a rotor with the precision of an oscillating quartz crystal. It’s essentially a hybrid movement, but the lion seal has become something more, too.

You see, the 9R15 is a souped-up version of the 9R65; it’s been tweaked to deliver even greater accuracy than the already highly accurate standard Spring Drive. Part of the reason has to do with the quartz crystal itself. Not all crystals are created equal, and only the best ones make it to the 9R15.

Along with a few other minor tweaks, this results in a movement that gains or loses just 10 seconds per month – that’s the equivalent of just 0.5 seconds per day. It’s obsessive, but it makes sense; if you’re going to create a brilliant homage to a movement, use the best version of that movement possible. On paper, it seems too good to be true, but given Spring Drive’s enduring reputation, it’s a spec sheet you can trust.

If you need to get your hands on it and want to test it out for yourself, Fraser Hart has the Grand Seiko Sport Spring Drive 20th Anniversary available now at One New Change. .