Zenith 685

	Brand:	Zenith
	Family:	Zenith Elite
	Height:	4.48 mm
	Jewels:	38
	Reserve:	50 hours
	Frequency:	28,800 A/h
	Winding:	Automatic, Bi-Directional Automatic Winding, Central Rotor Automatic Winding
	Diameter:	25.60 mm (11.5 ligne)
	Complications:	Date, Hacking Seconds, Instant Date Change, Power Reserve Indicator, Quick Date Correction
	Hands:	Central Hour Hand, Central Minute Hand, Date Window at 4:30, Power Reserve Pointer at 1:00, Small Seconds Hand at 9:00

Distinguishing Technical Characteristics
Central-Rotor Automatic Clockwise Balance Cock Balance at 1:30 Barrel at 7:30 Central Rotor
Production: 2002 – 2015
1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s

Cal. 685 is a thin automatic movement with date and power reserve from Zenith. Closely related to other Zenith Elite movements, Cal. 685 has a complicated look, with power reserve indicator between 1:00 and 2:00 on the dial, date window at 4:30 or 6:00, and small seconds at 9:00. It is similar to the hand-winding Cal. 655. The larger Cal. 687 is also similar but has a rotating 24 hour bezel around the dial.

Cal. 685 was used for many years in Zenith’s “Reserve de Marche” or “power reserve” models in the Captain, Classic, Defy, and Port Royal lines. Most early examples feature a date widow at 4:30 but later versions seem to have switched to a date window at 6:00. Cal. 685 was covered as a new movement in 2002 and remains in the catalog at least until 2015 but is no longer produced as of 2020. Although some coverage suggests it is 4.38 mm thick, Zenith’s official documentation lists it at both 4.48 and 4.67 mm. The component count is variously listed at 170 and 179 in official documents.

Cal. 6850 is a similar movement with an enlarged main plate, moving the date window out for larger watches.

Technical Aspects of the Zenith Elite Movement

The basic Elite movement measures 11.5 ligne (25.60 mm) diameter and most models are under 4 mm thick, despite a central automatic winding rotor and date complication. A few models used a larger main plate to move the date window outward or to support complications like a running 24 hour ring. The thinnest Elite movement is the hand-winding Cal. 650 at 2.83 mm and the thickest and most complicated is the large Cal. 687 at 6.20 mm.

Unusually, many Elite movements (apart from the 660 and 670 lines) feature small seconds at 9:00, a distinctive feature that differentiates the watches that use it. Some, however, feature central seconds, an adjustable 24 hour hand, a power reserve indicator, and other complications.

All Elite movements use an annular Glucydur balance wheel with a self-compensating balance spring and fine micrometer screw for adjustment. The automatic winding rotor is mounted on ball bearings like the ETA 2892 and originally included a tungsten carbide element for higher winding power. Most Elite movements boast 50 to 55 hours power reserve and all operate at 28,800 A/h.

Zenith Elite 680 and 690: Small Seconds

Cal. 680 was one of the original Elite movements introduced in 1994 and remains in production today. Most of its descendants feature small seconds at 9:00, though Cal. 690 lacks running seconds and the rare Cal. 689 relocates the subdial to 6:00.

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