Seiko Spring Drive Hand-wound Limited Edition, References SBWA001 and SBWA002

Seiko Spring Drive is a mechanical watch having accuracy equivalent to a quartz watch. This innovative technology was announced by Seiko at the 1998 Basel Fair. The first Seiko branded Spring Drive Hand-wound wristwatch models to be introduced into the market were SBWA001 and SBWA002.

Traditionally, the energy source of a mechanical timepiece is the mainspring and the regulating components are the balance spring and the escapement. The Spring Drive incorporates a mainspring just like a mechanical watch, but adopts an electronic speed-regulating unit comprising a generator, IC circuit, and crystal oscillator.

In 1999, the Japanese watchmaker introduced two Seiko Spring Drive watches: An 18K yellow gold version with a suggested retail price of 500,000 yen and a stainless steel case model with a suggested retail price of 250,000 yen (both excluding tax) for a limited period. Both belong to the world’s first wristwatch line-up with a Spring Drive mechanism. In the same year, a Credor Spring Drive watch was also launched.

Models SBWA001 & SBWA002

Limited to 500 pieces, the Spring Drive reference SBWA001 watch features a stainless steel case, matching metal bracelet and black dial.

The 18K gold Seiko Spring Drive Hand-wound model (reference SBWA002) was limited to 300 pieces. It features a silver dial and crocodile leather strap. Both timepieces house the Cal. 7R68 Spring Dive manual-winding movement.

While a general mechanical movement mechanically adjusts the time accuracy, the spring drive Cal. 7R68 utilizes a crystal oscillator (like a quartz watch) for regulating. As a result, the time accuracy of a spring drive watch is within ±15 seconds per month (equivalent to within ±1 second per day), which is comparable to that of a quartz watch.

At 10 o’clock on the dial, there is a power reserve indicator that shows the remaining drive duration. Spring dive watch features smoother sweeping-seconds hand, which is different from ordinary mechanical watches and quartz watches. The spring drive Caliber 7R68 also displays the date function at 3 o’clock. Equipped with 30 jewels, this movement provides a power reserve of 48 hours.

The beautiful movement with the Côtes de Genève pattern and the smooth rotation of the rotor are visible through the see-through case back. Both models were issued in a special luxury box for each type. Inside the box is a plate with a limited edition serial number.

Technical details

Collection: Seiko Spring Drive

Movement
7R68 caliber
Winding method: Hand-wound
Time accuracy: Monthly difference within ± 15 seconds (equivalent to daily difference within ± 1 second)
Power reserve: About 48 hours
Number of jewels: 30
Movement diameter: 29.0 mm
Movement thickness: 3.5mm

Functions
Hour, minute and centre seconds
Date at 3 o’clock
Power reserve indicator

Model: Seiko Spring Drive 18K Gold, Reference SBWA002

Case
18K yellow gold
Glass dual curve sapphire glass with double-sided anti-reflective coating
See-through back (sapphire glass)

Band
Crocodile with 18K yellow gold buckle

Edition
Limited to 300 pieces

Model: Seiko Spring Drive Stainless Steel, Reference SBWA001

Case
Stainless steel
Glass dual curve sapphire glass with double-sided anti-reflective coating
See-through back (inorganic glass)

Band
Stainless steel

Edition
Limited to 500 pieces