Seiko 5 Sports JDM Speed-Timer 7017-6010 – Caliber 7017, flyback chronograph with inner bezel, Daini Seikosha – February 1971 – freshly serviced

Press the bottom pusher, and the chronograph jumps back to zero—while continuing to run. No stopping, no resetting, no restarting. One press, and the measurement begins again.

This is called flyback. It is a complication that comes from aviation, where seconds counted, and which is otherwise found on watches that cost many times more.

The answer from Tokyo

In 1969, Seiko’s Suwa factory introduced the caliber 6139—one of the world's first automatic chronographs, which made the brand famous internationally.

A year later, the competing Daini factory in Tokyo responded with the caliber 7017.

For decades, Seiko maintained two completely separate production divisions that competed against each other—Suwa developed Grand Seiko, Daini developed King Seiko—and corporate management explicitly encouraged this. In the case of chronographs, this competition led to two completely different designs for the same task.

Daini placed two points of emphasis that characterize the 7017 to this day:

It was the thinnest. At 5.9 mm in height, the 7017 caliber set a world record for automatic chronograph movements at its introduction. Anyone who places a 6139 and a 7017 side by side can see the difference immediately.

It featured flyback. The 6139 cannot do that.

This watch bears the lightning bolt of the Daini factory in two places: on the dial under the WATER 70m PROOF lettering and on the case back.

Three hands, one ring – how the watch works

This watch has only three hands: hour, minute, and the orange chronograph hand. There is no sub-dial, no minute counter, no small second. The dial surface remains exceptionally uncluttered—and this is the point where most people pause: How do you measure more than one minute with it?

Via the internal rotating bezel.

The black ring with markings from 5 to 55 lies under the crystal and can be rotated. You set it to the minute hand at the start of the measurement; the orange hand tracks the seconds, the minute hand moves over the ring, and you read the elapsed time without having to calculate.

This also makes the flyback function make sense. A chronograph designed for sixty seconds thrives on being able to restart quickly in succession—for split times, laps, intervals. That is exactly what the flyback reset accomplishes. Two features that seem unusual individually result in a logical instrument together.

There is the added design advantage of the internal bezel over an external rotating ring: it cannot be adjusted accidentally, it does not collect dirt, it does not wear out, and it does not compromise the water resistance of the case.

Why you rarely see them

The 7017 series was built only from 1970 to 1972, after which Seiko discontinued it. It comprised only a handful of different references, and it was produced exclusively for the Japanese domestic market—not a single model was exported through regular channels.

The result is clear: While the Suwa 6139 and 6138 chronographs are known worldwide and exist in large numbers, even many Seiko collectors are unaware of the 7017s. They are simply scarce.

The caliber 7017

• Automatic chronograph with flyback function
• 21,600 semi-oscillations per hour
• Central chronograph hand in orange, measuring range 60 seconds
• Internal rotating bezel for measuring longer time periods
• Day and date with quick-set, day disk bilingual (Japanese/English)
• 5.9 mm movement height – a world record at market launch
• Manufactured by Daini Seikosha, Tokyo

On operation: The top pusher starts and stops the chronograph, the bottom one resets it. The flyback function means that the bottom pusher can also be operated while the chronograph is running—the hand jumps to zero and immediately starts again.

Many collectors let the chronograph on these movements run permanently. With the 7017 design, this is perfectly safe and distributes wear more evenly.

Dial and case

The matte black dial is divided into two zones: the inner part features the time display with applied, luminous baton indices, while the outer part has the rotating ring with fine graduations and white numbering in five-minute increments.

The Speed-Timer lettering is in orange directly under the SEIKO logo, and below that is the Seiko 5 badge. At the bottom of the dial, SPORTS / WATER 70m PROOF appears with the Daini lightning bolt.

The central chronograph hand is also orange, making it the only color accent on the black background—a design element that Seiko used consistently for its sports chronographs during those years.

The calendar window at three o'clock is framed by a light-colored border and displays the day of the week and the date. The day disk is bilingual and can be toggled between Kanji and English abbreviation; the photo shows Tuesday 火.

The stainless steel case is designed as a softly rounded cushion, with polished flanks, a brushed top, and a narrow, beveled bezel that frames the dial. The two pushers are located at two and four o'clock, with the crown in between at three o'clock.

It is a robust case—this is the price for an automatic chronograph, and it corresponds exactly to the design language for which Japanese sports watches from the early 1970s are sought after today.

Condition

Technically flawless. The watch was professionally serviced in Japan in the spring/summer of 2026—fully disassembled, cleaned, oiled, and regulated. The automatic winding, chronograph, flyback function, internal bezel, and quick-set day and date all work perfectly.

The dial is well-preserved: the matte black surface is uniform, the lettering—including the orange Speed-Timer inscription—is complete and sharp, the applied indices are firmly in place, the rotating ring has undamaged numbering, and the calendar frame is intact.

The luminous material in the indices and hands has aged to a warm beige and no longer glows. This is the norm for watches of this era.

The stainless steel case shows clear, age-appropriate signs of wear on the bezel, edges, and flanks—this watch has been worn. The basic shape is preserved; the watch does not appear over-polished. The pushers are complete and functional. The case back shows scratches from opening and wearing; all engravings—reference 7017-6010, serial number, Daini lightning bolt—are complete and clearly legible. The crystal shows light signs of use.

A third-party stainless steel bracelet is mounted; it is not the original Seiko bracelet.

Technical specifications

• Brand / Line: Seiko 5 Sports, Speed-Timer
• Reference: 7017-6010
• Serial number: 125647
• Production date: February 1971
• Movement: Seiko caliber 7017, automatic chronograph with flyback, 21,600 A/h, movement height 5.9 mm
• Manufacturer: Daini Seikosha, Japan
• Functions: Hours, minutes, chronograph (60 seconds, central hand) with flyback reset, internal rotating bezel, day and date with quick-set, bilingual day disk (Japanese/English)
• Case: Stainless steel, cushion shape, two pushers, case back with "WATERPROOF" marking
• Diameter (without crown): 43 mm
• Height: 13.6 mm
• Lug-to-lug: 45.7 mm
• Lug width: 19 mm
• Weight (incl. bracelet): 110 g
• Bracelet: Third-party stainless steel bracelet
• Crystal: Mineral glass
• Service: Spring/summer 2026, Japan – full disassembly, cleaning, oiling, regulation

For whom

For collectors who take Japanese chronographs seriously. Everyone knows the 6139. Very few know the 7017 from the competing Daini factory—yet it is flatter, technically more sophisticated, and was built in far smaller numbers.

For those who want a flyback chronograph. This complication is otherwise found in price brackets that have nothing to do with this watch.

For fans of thoughtful engineering. Three hands, a rotating ring, a flyback reset—together they make a fully functional measuring instrument on a dial that appears calmer than any conventional chronograph.

And for lovers of Japanese sports watches from the early 1970s: cushion case, matte black dial, orange chronograph hand, bilingual Kanji day disk. This combination was only available in Japan and only for two years.

Warranty (used)
This is a used item. The limitation period for claims for defects (statutory warranty) is 12 months from delivery.

Note
As this is a vintage watch, water resistance cannot be guaranteed. To protect the movement, the watch should not come into contact with water or moisture.