It all began at 2.5 Hz. Then 3 and then 4. The frequency movements beat at has long been a major issue, both technological and commercial, especially when technology was a major sales argument. The number of vibrations of the balance wheel inside a mechanical movement is one of the most reliable and prestigious ways to increase its accuracy. And when Zenith managed to perch the El Primero on the 36'000 vph branch in 1969, they defined a record that held for over 30 years.
It wasn't alone up there for long. Some, including Girard-Perregaux and Longines, managed to climb alongside, but they quickly moved away from this plateau, having failed to reap steady commercial success from it and having been plagued with heavy reliability issues. Consistently flying at « 36k » altitude is therefore a badge of honor. After several watches managed to overtake it with 6, 8 and 10 Hz movements around the year 2010, the aura of accomplishment around those who had reached that ceiling was slightly blemished. A glass ceiling, it was not anymore. Still, what an effort that little leap from 4 to 5 Hz had demanded !
So the 5-high club still is a rather small one. It has a dozen or so member brands, all of which still keep these high frequency movements going. High frequency being somewhat of an ironic term when one thinks that when the 5 Hz mark was reached by mechanical means, quartz movements headed straight for 32 768 Hz ! But considering the set of specific constraints the former face, 5 Hz puts one in rarefied air...and oil.
It so happens that lubrication is the crux of the high frequency matter. There nothing to having a balance wheel beating at high speeds. The issue lies with its companion parts, namely lever and escape wheel.
They sustain heavy friction which forbids them to stay the course. To circumvent this fatigue, one can either lubricate more or better. But because of high speeds, oil tends to be shaken away from the pallets. The stakes are obviously at their highest when the entire movement beats at 5 Hz, but constraints appear as soon as anything beats that fast, like the chronograph side of the Breguet Tradition Chronographe Indépendant 7077. Research in tribology has garnered significant enough progress as to render the point moot. Lubricants have become incredibly efficient and silicon parts are naturally friction-free, with no substance added.
Zenith (and therefore Bulgari), Patek Philippe, Grand Seiko, Vacheron Constantin, DeBethune, Parmigiani and Richard Mille via Vaucher Manufacture, Longines via ETA, Omega via Blancpain and the latter as a matter of course all master the 5 Hz art. But not all of them use silicon escapement parts. Zenith uses both, and Vaucher uses steel and rubies only. Which is further proof that watchmaking ingenuity is based in both radical innovation and in optimizing its existing tool box.
