Seiko 8R is a family of modern chronograph movements with advanced features like a column wheel, vertical clutch, and three-pointed reset hammer. Although newer and numerically higher than the Seiko 6S chronograph, it is considered to be slightly lower in terms of refinement and design. The 8R family is sold by Time Module Inc. (TMI) as Cal. NE86 and NE88 for use by third-party watch makers.
The 8R family was introduced in 2009 shortly after the related 6R family of automatic non-chronograph movements. Both use the proven 7S gear train and Seiko’s Magic Lever winding system. It is built on the 6R20 but is much more integrated than a traditional modular chronograph movement. Unlike the 6S, the 8R family uses a 3-6-9 subdial arrangement, albeit with running seconds at 3:00 rather than 9:00 as is traditional. The date window is placed at an angle at 4:30.
Seiko was the first to market with a vertical clutch column wheel chronograph in 1969 with Cal. 6139 and the company takes these technologies to a new level in Cal. 8R. Rather than driving the minute and hour counters from the chronograph seconds wheel, each is driven by a powered wheel with its own clutch. A unique three-pointed hammer starts, stops, and resets all three wheels simultaneously, and all the counters advance continuously rather than only at one-minute intervals.
Cal. 8R28 is the most common movement in the family and the first introduced. It is 7.2 mm thick, has 34 jewels and 292 components, and was used in the SRQ009/SRQ011 Ananta, SAGK001 and SDGZ001 Brightz, and SRQ001 Velatura. Introduced in 2011, Cal. 8R39 is 7.6 mm high and was made for dive watches, including the exclusive SRQ013 Ananta limited edition. Cal. 8R48 appeared in 2014 and has similar specifications but is made from 311 components and measures 7.5 mm thick. It was only used in Japan-market Brightz watches and the rare SRQ021 60th anniversary Laurel and SRQ023 Presage watches of 2016. Cal. 8R49 is nearly identical to 8R48.
TMI also sells an OEM version of Cal. 8R39 called NE88. Introduced in August 2014, it is listed at 7.63 mm thick. Cal. NE86 is similar but lacks the hour counter at 6:00, moving the date window there. TMI rates these movements as accurate to -15/+25 seconds per day.
|8R28A||7.2 mm||34||292||Original Movement|
|7.6 mm||34||306||Thicker, for dive watches|
|NE86A||7.6 mm||OEM 2-subdial|