The El Primero movement by Zenith is a watchmaking legend, with its rate of 36,000 vibrations per hour – 5 Hertz – that improves precision and provides an accuracy of a tenth of a second in chronograph readings. It was first introduced in 1969 and so we’re not far off 50 years. The three overlapping subdials have also become part of watchmaking history, originally anthracite, blue and light grey. In this new pair of watches, available from May 2017, the hallmark dial layout is available in two versions, with black subdials on silver dial, or vice-versa. It’s as if one were the negative of the other, all the scales are complementary in colour. Both display the subtle contradiction that for years has been part of El Primero: the design makes it impossible to take precise readings for certain elapsed times.
The chronograph seconds hand is long, running right across to the tachymeter scale, one of the few that has a fair number of subdivisions at least from about 140 down to 60. Just inside, there are two scales, for minutes, and fractional seconds. The seconds scale is logically divided into fifths of seconds but it is interrupted by the hour markers, each of which covers about half a second of the scale. The date window at 6 o’clock obscures another couple of seconds of the scale. The 30-chronograph-minute subdial on the right is overlapped by the chronograph hour subdial, so that if the measured time is between 15 and 22 minutes, you can’t time it. The continuous seconds scale on the left is also overlapped by the chronograph hour subdial but that’s no problem. In the Defy 100th second chronograph, Zenith made efforts to ensure the legibility of the scales: in this piece the scales have their customary iconic arrangement, but in my eyes it’s not a 100% practical layout. Zenith is not alone in the trend of chronographs in which design reduces legibility. Hands and hour markers have inserts of SuperLuminova.
The case is 42 mm in diameter, in black ceramicized aluminium, with a water resistance of 10 atm/100 metres. The watch is 12.75 mm thick, comparatively slim for a chronograph. The circular pushers are piston-type. The automotive feel is reinforced by the rubber strap with black PVD-coated folding clasp.
El Primero movement
The movement is the El Primero 400 B, self-winding, with a power reserve of 50 hours. It has 326 components, 31 jewels, and runs at 36,000 vibrations per hour. Watchmakers admire it. The chronograph functions are controlled by a column wheel, operating a horizontal clutch. The calibre can be viewed through the sapphire caseback. It is a COSC-certified chronometer, so with a precision within -4/+6 seconds deviation per day.
Prices and references
The Zenith El Primero with black dial and silvered subdials is reference 24.2041.400/21.R576, price €8,900. The version with silvered dial and black subdials is reference 24.2041.400/01.R576, same price. Further information from the Zenith website.