The Seiko 6139 and 6138 series - the fully serviced Japanese Domestic Market (JDM)-only 1973 Seiko 6138-0030 SpeedTimer "Champagne Kakume" automatic chronograph here counts itself among the latter - were the first fully integrated automatic chronograph in the world featuring column wheel and vertical coupling mechanism.
But you don't need to take our word for it the Kakume is a fantastically executed watch - per Worn&Wound, "The Seiko 6138-0030 Kakume is the epitome of a vintage Seiko. Funky 1970’s style yet timeless at the same time, quality made and beautifully designed and detailed dial, hands and bezel, perfectly integrated bracelet, [and] easily serviceable...couple this with the technically innovative and robust in-house manufacture movement and you get a simply stunning and incredible watch that will stand the test of time."
The unique square hour and minute subdials of these sporty 6138-0030’s provide the watch its nickname, “Kakume,” Japanese for “square eyes.” Unusual for the time, this 6138 is rather hefty in size, measuring in at 43mm in width.
With the 6138 movement, Seiko - as usual - set the standard followed by the Swiss watch industry 20 years later. The same movement configuration was adopted by Rolex when it made its own in-house movement for the Daytona in 2000, 30 years after Seiko released its 6139 and 6138 calibres. Oddly, the 6138 was the successor of the 6139 automatic chronograph movement, and produced in parallel with it until 1979.
The 6138 was technically at least equal to its Swiss counterparts, as it featured a fully integrated chronograph vice stacked modules. There were two versions of the 6138, with the first, the 6138A, introduced in 1970 with 21 jewels. The 6138B was introduced subsequent, and featured 23 jewels. Both had a column wheel that regulated chrono functions, and a vertical clutch mechanism for engagement.
Seiko's 6138A/B automatic movement is designed as a two register chronograph, counting up to 30 minutes on one subdial and another 12 hours on the second dial. All 6138 movements feature a quick-set day/date indicator and can be manually wound (unlike the 6139 model) - relatively unique for Seiko chronographs of this era.
This 6138 Kakume comes on a stainless-steel SpeedTimer oyster bracelet (see Details section), and with nylon strap, rugged travel case, and springbar tool.
1973 Seiko 6138-0030 JDM SpeedTImer "Champagne Kakume" Automatic Chronograph
DIAL: SpeedTimer Suwa-signed dial, with vibrant orange dial edge tachymeter and "SpeedTimer" wirting - not worn to a faded yellow like many lesser examples - and the rest of the dial script is crisply legible. Day and date function at the 3 o'clock position work as designed. Correct JDM "arrow" handset; chronograph hands show light UV patina.
CASE: Hefty stainless-steel case measures 43mm (w/o crown, 44.5mm with) x 45.5mm stainless-steel cushion case - which shows normal case wear, but no deep scratches - with sharp case lines and matching caseback. Bezel insert shows limited wear, despite its half a century life.
CRYSTAL: 6138 Hardlex crystal, scratch-free.
BAND: This Kakume comes on a sturdy stainless-steel oyster-style bracelet, which will fit up to an approx. 7.75 inch wrist - although we can confirm the clasp and endlinks are original to this watch, it bracelet itself may not be. The original style bracelet (as seen in the catalog picture in the listing) was known to be somewhat weak, and many replaced it. This Kakume also comes with a dark blue, orange, and white nylon strap.
MOVEMENT: 6138B Seiko 23-jewel automatic movement, manufactured in November 1973, which beats at 21,600 beats per hour. We have performed a full service on this 6138 Kakume.
CROWN: Unsigned stainless-steel crown.