Collectible! Birthday Watch April 1972! Seiko 5 Sports Speed-Timer 6139-8010 Chronograph JDM SUWA 21J, Automatic Watch (OH)

A BIRTHDAY WATCH IS A WATCH THAT WAS PRODUCED THE SAME MONTH AND YEAR AS YOUR BIRTH MONTH AND YEAR

Make: Seiko
Type: Automatic
Model: Sports 5 Speed-Timer
Year of Production: April 1972
Movement: 6139B
BPH: 21,600
Number of Jewels: 21
Hand and Dial: 3D Baton Indices with Pencil Hands
Width: 41mm
Lug to Lug Height: 40.5mm
Thickness: 15mm
Lug Width: 18mm
Bracelet: Existing Seiko 5 Sports Signed Black SS Bracelet
Pouch / Box: Brand-New EVA Type Zipper Pouch

To fully understand her history, kindly read-on!

"Today, self-winding (or automatic) chronographs are quite common. Omega created a prototype of one back in 1948 but later abandoned their production plans. Over 20 years later, two companies and one collaboration would finally make it to series production: Seiko, Zenith, and a joint venture between Heuer, Breitling, and Hamilton. These manufacturers all introduced and launched their automatic chronograph movements in 1969, and this watch style would quickly become very popular throughout the industry.

"Of the three calibres, the Seiko 6139 has had the greatest influence on future generations despite being the least well known. This movement centers on its vertical clutch and compact automatic rotor, a design many manufacturers have imitated since the 1980s. In fact, Frederic Piguet turned to the 6139 when crafting their legendary caliber 1185, which some call the “grandfather of the modern automatic chronograph.” Considering how many automatic chronographs the 1185 has inspired, there’s no denying the 6139’s influential role.

"In 1969, Suwa Seikosha put the final touches on the caliber 6139, complete with a Magic Lever and vertical clutch system. On May 21, 1969, Seiko officially debuted the movement under the name “61 Speed-Timer.” However, the caliber had already begun appearing in watches as early as January of the same year; you can still find examples from those early months today. Seiko published the first advertisement for their new automatic chronograph in February 1969. Both the company and Ohki were unaware that the 61 Speed-Timer was the world’s first automatic chronograph movement. At the time, Seiko was busy planning the release of the quartz Astron later that same year." - The Chrono24 Magazine.

Thus, the Seiko 6139 Chronographs can be considered the great-grandfather of the modern automatic chronograph timepiece that took the world by storm.

The 6139 is the world’s first automatic chronograph that uses a column wheel and vertical clutch. The 6138 followed shortly afterwards. Both were nicknamed “61 Sports Speed Timers” even though certain models did not indicate these wordings.

Both movements were developed in 1969 for different tasks. The 6138 was developed on the 6139 platform but with the intention of having an added chronograph hand to measure elapsed hours; and it also included the column wheel and vertical clutch for more precise stopwatch measurement. But, unlike the 6139 that has only one sub minutes dial, the 6138 comes with two ~ a 30-minute counter and a 12-hour counter.

Here we have an April 1972 6139B-8010 in stunning condition.

A deep cleaning was conducted on the midnight black main dial, mini-dial, silver day/date window, chapter ring, 3D-styled baton indices, hands, and mini-dial hand as well. They are now in stupendous condition that is extremely pleasing to the eye.   

Its cylindrical shaped black case with built-in lugs was deep cleaned and buffed to reveal a fantastic finish albeit a few minor scratches that comes with age. The crystal was replaced with an NOS Seiko crystal and is now in stunning condition.

The crown is located at the traditional 2H, 3H and 4H positions and are nicely tucked away to prevent damage or snags. The day / date and hands quickset works as it should by pushing in the 3H crown to the first and second levels to adjust respectively. Crown 2H is for the chronograph start/stop and the 4H is for the reset of mini-dial and main second hands. All are working as they should. The inner Rotating Bezel with Orange markings works smoothly and is adjusted via the 3H crown when in locked position.

Because this is a JDM, the Day is in English and Kanji, cool!

The movement was carefully stripped, meticulously cleaned, oiled, re-assembled, and calibrated on 17 September 2025. In short, it was given an overhaul and not a general servicing. It should be able to operate unhindered until the next servicing thereby providing the owner peace of mind.

Equipped with the highly prized 6139B movement, it has 21 Jewels and operate at 21,600 BPH. The time-grapher shows stunning readings of 0 seconds and amplitude of 182 with a very straight centered line! Such readings are truly exceptional even by brand new modern automatic watch standards whereby the accepted tolerance is -20 to +40 seconds a day! This is a testament to the quality, the meticulous care provided over the years, and expert calibration.

The case width and height are approximately 41mm (w/o crown) and 40.5mm respectively. The lug width is 18mm and the bracelet can accommodate wrists up to 19.0cm; hence, this watch is suitable for men and the modern women.

The bracelet is the original black Seiko 5 Sports SS Bracelet that accompanied this watch when it was produced. It too was given a deep cleaning and is now in excellent condition. There are miniscule scratch marks commonly found in aged watches.

To the best of our knowledge and expertise when overhauling the timepiece, the watch is 100% original Seiko components from this particular watch. No parts were replaced with aftermarket parts.

Due to its age, this timepiece has not been water-resistant tested.

The pictures provided shows the watch in superb condition, and the movement within squeaky clean and well maintained. It has also been demagnetised to improve parts reliability, minimise wear + tear, and improve accuracy. The only drawback is the lack of documentation and original box. An aftermarket box or purposeful carrying case will be provided instead.

Bear in mind that this watch has seen many of the previous owners’ ups and downs in life, and should be cherished and preserved for the next generation to savour such engineering beauty.

Yes, there are many other same / similar models in the market, BUT none as beautifully aged and as well maintained as what you see here. Hence, it is a no-brainer that this one-of-a-kind watch will make an extremely beautiful birthday present for that special someone born in January 1970! Another no-brainer is the fact that the value of this watch will appreciate over time.

Do also bear in mind that it will cost between S$ 300.00 to S$ 500.00 for a proper overhaul, an estimated S$ 120.00 to calibrate (depending on watch condition), and S$ 120.00 to clean and polish including tightening of bracelet links - these costs do not apply when purchasing this timepiece. So, if anyone was to sell such a timepiece at a low price yet claim that it has been serviced, one has to ask what kind of servicing was conducted, if any.

This is a highly sort-after Seiko 5 Sports 6139-8010 Speedtimer; so, be unique and own a watch that is almost impossible to source.

This is a must-have for the Seiko die-hard fan, and in fact, any serious watch collector!