Presented for auction by Second Vintage The Seiko 6139 stands as a monumental achievement in horological history, recognized as one of the world's very first automatic chronograph calibers introduced during the fiercely competitive race of 1969. Within this legendary lineage, the 5 Sports SpeedTimer variants hold a special place among collectors for their bold, unapologetic 1970s aesthetic and motorsport-inspired design language. This specific example captures the essence of that era perfectly, combining a robust, geometrically complex case with a highly legible and colorful dial layout. It is a highly charismatic vintage chronograph that represents a significant chapter in Seiko’s innovative past. Brand: Seiko Model: 5 Sports SpeedTimer Chronograph Reference Number: 6139-7020 Serial Number: 152657 Movement: Caliber 6139B, 17 Jewels, Automatic Chronograph Dial: Matte black dial with a distinct two-tone blue and black sub-dial, exhibiting heavy and crusty aging to the luminescent markers. Case Size: 41 mm (excluding the crown) Case Material: Stainless Steel Production Year: 1971 Condition: Good vintage condition with honest case wear and prominent dial patina. Dial and Hands The matte black dial serves as a high-contrast backdrop for the vibrant, motorsport-inspired accents characteristic of the SpeedTimer line. An applied silver-tone Seiko logo sits above the printed 5 Sports designation, while the cursive Speed-Timer text is rendered in a striking orange at the nine o'clock position. At six o'clock, the thirty-minute chronograph register features a distinctive split-color design, with the first fifteen minutes highlighted in a bright blue and the remainder in black. The dial surface itself remains relatively clean, but the luminescent hour markers exhibit heavy, crusty, grayish-white degradation and crumbling, reflecting significant environmental aging over the decades. The day-date aperture at three o'clock provides a sharp, framed display. The white baton hour and minute hands show age-consistent darkening to their luminous fills, while the central orange chronograph seconds hand and the matching sub-dial hand display visible spotting, oxidation, and slight color fading under close loupe inspection. The outer minute track and dial codes, including JAPAN 6139 -7050T, remain fully legible. Case and Crystal The forty-one millimeter stainless steel case features a prominent cushion or helmet-style profile that is highly emblematic of 1970s Seiko design. The upper surfaces retain distinct, heavy vertical brushing, which transitions sharply into polished case flanks. Honest signs of vintage wear, including light scratches, handling marks, and minor edge softening, are visible throughout, though the case retains its strong factory geometry without appearing over-polished. The fixed black outer bezel frames the dial securely and shows minor surface marks consistent with regular use. The chronograph pushers at two and four o'clock, along with the deeply recessed crown at three o'clock, are seated correctly against the case. The crystal remains clear and provides an unobstructed view of the dial, showing only faint, superficial handling marks. The screw-down caseback is sharply engraved with the Suwa logo, reference numbers, and the serial number indicating a production date of May 1971. Movement Powering this timepiece is the historic Seiko Caliber 6139B, a seventeen-jewel automatic chronograph movement featuring a column wheel and vertical clutch. Visual inspection of the movement reveals clean plates, a signed Seiko rotor, and distinct Japan stampings, alongside beautifully oxidized levers that showcase the mechanical complexity of this early automatic chronograph. Exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. Timegrapher results show +14 to +18 s/d. Strap The watch is fitted with a period-correct, aftermarket black leather strap featuring prominent white contrast stitching. The strap conforms comfortably to the wrist and complements the sporty, monochromatic elements of the dial and outer bezel. It is secured by a standard stainless steel pin buckle. Condition This timepiece is presented in good vintage condition. The stainless steel case displays normal, honest wear with visible handling marks and light scratches, yet retains its bold original brushed and polished surfaces. The dial is characterized by extreme, crusty patina to the luminous plots and visible oxidation on the hands, presenting a highly textured and heavily aged aesthetic that speaks directly to its vintage nature. The movement is visually clean and operational. Dimensions The watch measures 41 mm in diameter, excluding the recessed crown. The robust cushion case design provides a substantial and commanding presence on the wrist, sitting comfortably due to its integrated lug profile. Remarks This 6139-7020 SpeedTimer is a superb representation of 1970s Seiko chronograph design. The combination of the heavy cushion case, the striking blue and black sub-dial, and the heavily patinated markers makes this a rugged, character-rich timepiece. It is a watch that proudly wears its age, appealing directly to collectors who value mechanical pedigree and authentic, unpolished vintage character. History In 1969, Seiko shocked the Swiss watchmaking establishment by releasing the Caliber 6139, widely debated and celebrated as one of the very first automatic chronograph movements ever brought to market. The 5 Sports SpeedTimer line was introduced to capitalize on this groundbreaking technology, offering robust, highly legible, and stylistically daring chronographs aimed at a younger, active demographic. These watches became legendary for their durability and distinctive styling, cementing Seiko's reputation as a powerhouse of mechanical innovation during the golden age of sports chronographs. Payment and Shipping Payment must be completed within 1–3 days after purchase. Your watch will be professionally and very securely packaged, and shipped with tracking and insurance for your peace of mind. We ship via fast express service, with typical delivery in 1–4 business days (destination dependent). Note that with vintage watches, minor signs of wear, aging, or imperfections may be present and are considered normal for watches of this age. Please review all photos carefully before bidding. We strive to photograph each watch from multiple angles for the most accurate representation. The photos form an important part of the description. If there are any concerns of functionality or defects after delivery, make sure to contact us within 3 days of receiving the watch so we can assist you. As with all vintage watches, water resistance is not guaranteed. If you have any questions, feel free to contact us after the auction ends. / Second Vintage SKU: SEI-SXX-0018