There are watches with a large balance wheel and there are watches with a very large balance wheel. Remember the Heritage Watch Manufactory Tensus, it has a very large balance wheel. Remember the Zenith Montre d’Aéronef Type 20? That one has an even larger balance wheel.
Antoine Martin introduces the Slow Runner with a mind-blowing HUGE balance wheel. Its diameter is almost as big as most movements, and I mean the entire movement, not just their balance wheels. As the name indicates, it beats at an incredibly slow pace, with just 7,200 vibrations per hour.
The balance wheel measures 24 mm in diameter! OK, let this digest for a second. Especially when you consider that the diameter of the ETA 2824 and an ETA 2892 movements measures 25,6 mm in diameter. The larger the balance wheel, the bigger the mass inertia and the better the chronometric rates that can be achieved. Unfortunately Antoine Martin does not mention anything about mass inertia nor the watch’s chronometric rates.
The 42 mm large Slow Runner comes in two stainless steel versions and in a rose gold version. Hours and minutes are in a large off centre sub dial, that is for a large part overlapped by a big seconds sub dial. At the 3 o’clock position is the date indication and at 10 o’clock is a power reserve indicator, telling you how much of the 92 hours of power reserve are left.
Both stainless steel versions come at a very competitive price of 19,500 CHF (before tax). A price of the rose gold version isn’t mentioned yet. The case features a mixture of brushed and polished part and the dial, or at least the part that is visible around the sub dials, has a nice brushed sunray finish. All three sub dials (hours/minutes, seconds and power reserve) are partially recessed, giving the wearer a lot to enjoy while checking the time.
The seconds hand ticks 2 times every second, perfectly in pace with the HUGE balance wheel. On the dial is indicated that it vibrates with 7,200 vph. This does however not mean that its seconds hand ticks 1 time per second, as one would expect with a timepiece with “one hertz” printed on the dial. These two words remind us of a timepiece with a seconds hand that does tick one time per second, and goes by the name One Hertz. Even the dial layout shows some resemblance with the Grönefeld One Hertz!
Let’s have a look at the beat rate or vibrations per hour. The vibrations per hour, stand for how many times a balance wheel swings in one direction, all “ticks”. This rate stands for how many times per second the seconds hand ticks. This is also expressed in hertz and that’s where things get slightly odd. Takes for instance a fast beat movement that vibrates at 36,000 vph and has a seconds hand that makes 10 tiny jumps every second. While the seconds hand jumps 10 times, it is called a 5 Hz watch.
- 36,600 vph – 5 Hz – ticks 10 times per second
- 28,800 vph – 4 Hz – ticks 8 times per second
- 21,600 vph – 3 Hz – ticks 6 times per second
- 18,000 vph – 2,5 Hz – ticks 5 times per second
- 7,200 vph – 1 Hz – ticks 2 times per second
The balance always swings in two directions, which always results in two ticks of the seconds hand. These tic/toc (two ticks) are called one hertz. This grabs back on the swinging of a clock’s pendulum, which is the balance wheel in modern wrist watches. When looking at the seconds hand of a watch, it sounds odd as one would expect that two ticks per second equal 2 Hz.
The in-house caliber AM 36.001 measures 36 mm in diameter and 8.6 mm in height and comprises 199 individual parts (23 jewels). The press release does not mention anything about the finishing of the movement, but let’s be honest, for a price of 19,500 CHF you cannot expect extensive hand finishing.
The Antoine Martin looks like a very attractive timepiece, that comes at a very attractive price as well. The main feature is visible through the sapphire crystal in the case back, being the immense balance wheel. That will surely make a lovely visual display for watch connoisseurs!
For more information, please visit the Antoine Martin website.
This article is written by Frank Geelen, executive editor for Monochrome Watches.