Omega Chronostop Geneve Collection Chronograph 1970 Ref 146.012 Serviced 03 2026

Echoes of the Speedmaster

Despite the low price, the Chronostop was a premium model. The watch’s movement seemed simple, but it was a high-accuracy, high-beat, high-quality engine, essentially a simpler version of the movement that powered the Speedmaster. Omega used two movements for its Chronostop models: the cal.920 (with a date), and the cal.865 (no date). Both manual-wind movements had 17 jewels, run at a rapid 21,600 Bph, and were used only on the Chronostop.

The cal.865 movement was introduced in 1966 and Omega used that model for 124,000 Chronostops. The cal.920 movement appeared in 1968 and was used for 61,000 watches.

The Chronostop was well-regarded within the watch industry: the watch won the 1967 Honor Prize for “Chronographs and Sport Watches” in the competition sponsored by the Swiss Watchmaking Federation to boost creativity. The Chronostop also took the first prize for Industrial Aesthetics at the Utrecht Spring Fair in 1968.

An official Olympic timer

Even though the Chronostop featured only one measurement function, it was selected as the official Omega timer at the Pan-American Games in Winnipeg and the 1968 Olympic Games in Mexico. Available in olive green, red, white, and blue, the Mexico Olympics versions of the watch used the cal.920 movement with the date function and included dial-matching leather straps.

Chronostop variations

Omega made the Chronostop in four different shapes and sizes. I prefer the design of the large, cushion-case Chronostop, especially the models with rotating inner bezels. These bezels feature fixed tachymeters, pulsemeters, telemeters, decimal scales, or even 60-minute diving timers. The Regatta has a 60-0 scale with the last ten minutes marked in blue and red. The Pilot’s scale has numerals graduated in pairs from 12-24, 1-13 and 2-14 onwards to show the time in 24 and 12 hour time zones. With such colorful trim, this watch has acquired the nickname, “the Roulette.” In 1970, Omega relisted a Chronostop model made specifically for the Italian market; this variation had a roundish “UFO” Omega Dynamic case and used the same integrated strap system. 

Using the stopwatch

To be honest, the Chronostop is not the most functional chronograph ever made, but at least it is fun to use. The second hand for the stopwatch is started by pressing the single pusher, then pressed again and held to freeze the hand and read the seconds. Release the pusher and the hand fly back to 12 o’clock zero.

Despite the limitations of the Chronostop, some people found a good use for the specialized stopwatch: doctors and nurses used the timer to take patients’ pulses, and engineers and technicians working with production lines found the feature to be handy. 

The Chronostop will be remembered for its unique place in the Omega line; it continues to appeal to collectors interested in its specialized functions.