In the second installment of our three-part series in partnership with Grand Seiko, we go in-depth on the history and development of Spring Drive.

Spring Drive is one of the most widely known of all the innovations created by Seiko in its entire history – but perhaps also the most misunderstood. This is partly because nothing like Spring Drive exists anywhere else in modern watchmaking: a watch regulated by a quartz oscillator, but one which is driven by a mainspring, has a completely conventional gear train, and has no battery.

For the full story, go to https://www.hodinkee.com/articles/ins...