A fast-beat movement offers an advantage over its lower-frequency rivals: more beats per hour means greater precision. The principle is simple: the accuracy with which time can be measured and displayed is inversely proportional to the size of the units into which it is divided. Fast-beat movements are also more shock-resistant than slower-beat ones, and this is an added boon to precision.

Two companies make series-produced movements with frequencies of 36,000 vph. One is Zenith; the other is Seiko. We tested one Rolex replica watches store from each brand to find out how they measure up against each other in terms of precision and a host of other criteria.

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The Zenith replica Rolex watches sale, called the Espada, is equipped with a modified version of the company’s celebrated El Primero movement. In its “natural” form, the El Primero is, of course, a chronograph movement. To make the Espada’s movement, a three-hand automatic caliber called the El Primero 4650B, Zenith removed the chronograph mechanism from the El Primero. The Seiko watch, called the Grand Seiko Hi-Beat 36000, contains the automatic Caliber 9S85, introduced in 2009.

Both movements required much work to develop. Modifying the El Primero chronograph caliber to power a three-handed cheap Rolex replica watches involved more than merely reducing the number of parts from 280 to 210. The stopwatch mechanism was removed, but it was partly reinstalled afterward. The bridges had to be redesigned and the continually running seconds hand relocated from an off-center subdial to the center of the dial. The resulting construction resembles the classic pattern of a basic caliber in which the central seconds hand is positioned directly within the flow of force rather than drawing its power from a rudiment left over from the chronograph mechanism.

The Grand Seiko’s elegant dial boasts neatly crafted indices and hands.

Seiko faced its own challenges. It spent five years developing a special alloy, Spron 610, for its caliber’s hairspring (Seiko makes its own hairsprings and mainsprings). Spron 610 has greater resistance to shocks and magnetism than standard alloys. Because a high frequency puts additional stress on the movement, Seiko redesigned the lever, escape wheel and pallets to increase their longevity. It developed another alloy, Spron 530, for use in the caliber’s mainspring. Spron 530 enables the spring to withstand the stronger torque required by the high-frequency balance: the torque in five-hertz Caliber 9S85 is twice as high as in Seiko’s four-hertz calibers. The spring provides an impressive power reserve of 55 hours.

Seiko’s fast-beat 9S85, launched in 2009, incorporates several technical innovations.

Zenith did not add a stop-seconds function when it modified the El Primero movement. You might ask what the point is of having an extremely precise movement in a plain automatic Omega fake watches, with no chronograph, if you can’t set the watch with to-the-second accuracy. We tried using an old trick to stop the seconds hand: pulling the crown out to the hand-setting position and then gently turning it counterclockwise. It didn’t work. The seconds hand had so much play that it jumped backward a full five seconds. Seiko’s watch does have a stop-seconds function.