Seiko Prospex Speedtimer Automatic silver dial steel bracelet 39,5 mm

Speedtimer Collection

The Speedtimer holds a special place in Seiko’s history and in that of the modern chronograph. In 1969, the Japanese brand made history by unveiling the Caliber 6139, one of the very first automatic chronographs featuring both a vertical clutch and a column wheel — a technical achievement that would permanently shape the world of sports watches.

The current Prospex Speedtimer line draws on this racing heritage, reinterpreting the design codes of the 1970s with a contemporary approach. More than just a nostalgic nod to the past, it offers timepieces designed for enthusiasts of precision, reliability, and functional design.

The SPB513 follows this lineage with a distinctive approach: unlike the better-known Speedtimers (most often chronographs), this model adopts a three-hand + date configuration, enhanced with an inner countdown bezel. A simple yet practical complication rooted in the racing spirit, it allows the wearer to measure short intervals — from the start of a race to boiling pasta — all while offering a sleek and versatile design.

Design & Aesthetics

The Seiko Prospex Speedtimer SPB513 takes direct inspiration from the 1972 Speedtimer, a historic piece that combined precision and functionality in a three-hand format. It translates that spirit into a modern execution, more refined and better suited to today’s needs.

The silver dial, strikingly clear, recalls the timepieces of the 1970s while benefitting from Seiko’s modern finishing expertise. Black applied hour markers punctuated with luminous dots stand out with strength, while the faceted hands receive Lumibrite treatment to guarantee perfect readability by day or night. A sporty accent enlivens the design: the central seconds hand is tipped in orange, echoing the colored graduation of the final 15 minutes on the inner bezel.

This inner bezel is a key functional and aesthetic element. Inspired by vintage chronographs, the rotating countdown bezel is operated via a secondary crown at 4 o’clock. It allows for precise interval timing, reinforcing the connection between the watch and the world of motorsport.

The 39.5 mm stainless steel case, with a thickness of 12 mm, reprises the faceted profile characteristic of vintage Speedtimers, but with updated proportions that ensure comfort and versatility. Alternating brushed and polished finishes create elegant plays of light, while the 200-meter water resistance confirms its robustness.

The SPB513 comes on a multi-link steel bracelet in a Jubilee style, another nod to 1970s models. Flexible and comfortable, it adds a vintage touch while ensuring perfect security thanks to its push-button folding clasp.

Movement & Performance

At the heart of this Speedtimer beats the Caliber 6R55, an in-house automatic movement that showcases Seiko’s expertise in designing reliable and robust calibers. As part of a recent generation, it offers an extended 72-hour power reserve, giving the wearer three full days of autonomy — meaning the watch can be left aside over a weekend without stopping.

Main technical specifications:

• Type: automatic with manual winding option
• Frequency: 21,600 vibrations/hour (3 Hz)
• Jewels: 24
• Power reserve: approx. 72 hours
• Functions: hours, minutes, seconds, date at 4:30

The hacking seconds function ensures precise time setting, a welcome feature for detail-oriented wearers.

Although Seiko officially announces an accuracy tolerance of –15 to +25 seconds per day, real-world performance reported by many users is often better, demonstrating the movement’s consistency. Designed to withstand everyday challenges, it also offers magnetic resistance up to 4,800 A/m, further reinforcing its reliability in modern, electromagnetically saturated environments.

By blending historical heritage, contemporary technology, and proven durability, the 6R55 makes the SPB513 a versatile mechanical watch, ready to accompany its wearer in both everyday life and more demanding situations.