The Clifton Baumatic was highly praised in the Japanese edition of Chronos. The first model was a fully anti-magnetic model, but the following year it was redesigned into a "normal" model with an anti-magnetic inner case. I wrote that it was unfortunate that the Japanese edition of Chronos changed this, but what was the actual situation?
Text by Masayuki Hirota (Chronos-Japan)
The perception that it was a "cheap version" was a misconception
The 2020 Clifton Baumatic is merely a cosmetic change to the existing model. In other words, it is the same as the "regular" antimagnetic model released in 2019. However, it seems I was mistaken.
According to Baume & Mercier, "The 2019 model has an anti-magnetic case, but the back cover is see-through." In other words, when you look at the watch, there is no difference between the 2018, 19, and 20 models. What was misleading was the explanation that "the movement is enclosed in an anti-magnetic case."
The 2018 Baumatic was equipped with the Caliber BM12-1975A movement. This movement, with its silicon escapement and balance spring, was resistant to magnetic fields of up to 1500 gauss. The 2018 press release also included detailed information about the new silicon balance spring, the Twin Spear. The editorial team at Chronos Japan was so amazed and delighted by this movement that they visited Valfleurier, the company that developed it. We wrote (more or less) about this outstanding movement in Issue 78.
The BM13-1975A, released the following year, had no information about it, but it also had the same magnetic resistance of 1500 gauss. If you put a magnetically resistant case in it, you can achieve this level of magnetic resistance even without a silicon balance spring or escapement. So it's not surprising that some people thought of the BM12 as a cheaper version of the BM13, and I was one of them.
The new Baumatic is also resistant to magnetic fields up to 1500 gauss.
Furthermore, even in the press release for the new "Clifton Baumatic Date COSC," there's not a single mention of its 1500 gauss magnetic resistance. It simply states, "The in-house developed automatic caliber, the Baumatic BM13, is a COSC (Swiss Official Chronometer Testing Institute) certified chronometer with a five-day power reserve." Just as I was starting to feel disappointed, wondering if magnetic resistance had finally been eliminated, Hosoda from the editorial department opened a document and said, "The new Baumatic also has a 1500 gauss magnetic resistance rating." Indeed, when I looked at the price list, I saw that it said 1500 gauss magnetic resistance in small letters. Seriously?
There was good reason to believe that the Baumatic had finally lost its anti-magnetic properties. In 2019, I heard that the silicon balance spring of the Twin Spear, which had been introduced with much fanfare, was covered by a certain company's patent. Although I wasn't an insider, this information was entirely reliable. The official explanation was that this was due to maintenance considerations, but I believe this is not the case. As a result, the Baumatic was redesigned to include an anti-magnetic case, and in 2020, I was led to believe that it had finally lost its anti-magnetic properties. This is understandable, considering that neither the press release nor the website mentions 1500 gauss magnetic resistance.
They had invented a secret technique to give it magnetic resistance.
However, Baume & Mercier has devised a trick to give the watch 1500 gauss magnetic resistance without using the Twin Spear's silicon balancer, using a see-through back. I thought this would be the case from 2020, but Baume & Mercier says, "This change was made with the 2019 model." While the BM13-1975A no longer uses silicon balancer, the escapement is still made of silicon, so it's already quite resistant to magnetic fields. Additionally, by inserting antimagnetic material into the dial and replacing the movement holder with a chrome core material (an alloy of brass and chrome), the watch has achieved the same 1500 gauss magnetic resistance as before. Even though the back is see-through, it's still impressive that it can withstand 1500 gauss.
The BM13-1975A, which is equipped with this movement, shares its basic design with Cartier's 1847MC. It uses a ratchet-type MagicClick winding mechanism, the same wheel train arrangement, and the same pillar-supported bridge structure. The biggest difference is the barrel. By enlarging the baseplate diameter to 28.8mm, it was possible to install a larger barrel with a power reserve of approximately five days. The BM13-1975A, which features a silicon balance spring, had a free-sprung balance without a regulator. This is understandable, as a silicon balance spring could break if it were pinched by a regulator. In contrast, the BM13-1975A, which has a conventional balance spring, has an etachron-style regulator. The balance bridge still has a notch for adjusting the free-sprung mass slot, suggesting the change was made suddenly.
I haven't tried the BM13-1975A, but based on my impressions of its sibling, the 1847MC, and the 2018 Baumatic, I imagine it will feel good. The chrome core makes it slightly heavier than models with silicon beards, but the thin case means this shouldn't have much of an impact. The case is 0.8mm thicker than the 2018 model, likely due to the addition of an antimagnetic plate.
Well, the Japanese edition of Chronos once praised this model to the point of calling it the best practical watch. Even in 2020, it has undergone some slight changes, but we're delighted that its individuality has not been diminished in the slightest. Moreover, the price of the three-hand model is 340,000 yen (excluding tax; 330,000 yen with a leather strap), with a COSC chronometer, 1500 gauss magnetic resistance, and a power reserve of approximately five days. Well, as a mechanical watch for everyday use, I think it's very good. I haven't seen it yet, though.
http://www.webchronos.net/2020-new-watches/45171/
http://www.webchronos.net/features/22213/
