Grand Seiko 9R Spring Drive

Spring Drive is the most advanced watch movement in the world, combining traditional master craftsmen's with the most advanced electronic technology.

What is Spring Drive?Early days of developmentThe purity of Grand Seiko design

The development of spring drive

When, nearly 30 years ago, Yoshukazu Akahane had the idea of Spring Drive, he knew at once that his dream was not realisable with the technology then at his disposal. It required major advances in every aspect of watchmaking to make it possible.


27 years of research, development and determination
Prototype 1
Prototype 1
Prototype 2
Prototype 2

It took 27 years, over 600 prototypes and massive investment of time and ingenuity, to create the new materials, components and manufacturing processes that Spring Drive required. The project began in 1977 and was finally brought to market in 2004.

Grand Seiko and Spring Drive. A perfect union

Grand Seiko is the very best of SEIKO's design. And Spring Drive is the very best of SEIKO's watchmaking art. Thus, it was natural that Spring Drive would be added to the Grand Seiko collection at the first opportunity.

From 1960, Grand Seiko has been based on mechanical calibers, but a quartz caliber was added in 1988 and now Spring Drive completes the collection of SEIKO's leading technologies in Grand Seiko.

The high-efficiency winding system of Spring Drive

Spring Drive's high efficiency winding system delivers a power reserve of 72 hours and allows the spring to be fully wound with just half the energy of previous systems. The system is based on a SEIKO innovation that was introduced back in 1959, the Magic Lever. This reliable system not only offers efficiency in winding but also advantages of long term reliability and durability. For Spring Drive, this tried and tested system was adopted, but all the components, the lever, material and gear axes , were redesigned.

How we achieved 72-hour power reserve

What is the optimum power reserve in a traditional watch? While there is no obvious answer, other than 'the longer the better', most people agree that what they need is to have the watch still working on Monday after their weekend, So the goal of the Spring Drive designers was to create a power reserve of 72 hours. An easy solution would have been to make the watch bigger, but that would limit the exterior design possibilities, so minimizing energy consumption was set as the goal.


How we achieved 72-hour power reserve

The tasks were to reduce the power loss in the gear train, to develop a more power efficient IC and minimize the loss of electromagnetic power . Solutions to all three challenges were found using SEIKO's own in-house technologies.


The core of the coil is made from 18 layers of 25-micron ultra thin amorphousThe core of the coil is made from 18 layers of 25-micron ultra thin amorphous

To deliver increased electrical power, it was decided to use amorphous for the core of the coil, even though amorphous is known to be a difficult material to process and to laminate. New solutions in the cutting and processing were found , resulting in greatly reduced loss of electromagnetic power ; the core is built from 18 layers of 25-micron ultra thin amorphous.

Perfect alignment of the coil winding.

The mathematics are simple. The amount of electricity generated is calculated by multiplying the rotation speed of the rotor, the intensity of the magnetic power and the number of times the coil is wound. The tri-synchro regulator of caliber 9R65 achieves efficient electric power generation with a new coil block around which the coil is wound a remarkable 25,000 times.

Ordinary coil winding
Ordinary coil winding
Coil winding of Spring Drive
Coil winding of Spring Drive
A true manufacture

SEIKO is one of the very few 'manufactures' that has achieved true vertically integrated watchmaking. Does this matter? Yes, in hundreds of ways. For example, SEIKO's own dial finish technique is used in the polishing of the oscillating weight, which would not be possible if the components were not made in-house.

"9". The perfect number.
"9". The perfect number.

SEIKO produces literally hundreds of different watch calibers, but only a very few have numbers that start with 9. Why? At SEIKO, the number 9 is reserved for the utmost quality calibers. Spring Drive caliber 9R65 is, of course, one of these.