There are still very few mechanical watches for women. This is because mechanical watches do not fit into the lifestyles of many women. However, some manufacturers have begun to produce fully usable mechanical "engines." This year, Bulgari added a new automatic watch for women, the BVS100 Lady Solotempo. Perhaps this will be the catalyst that opens the door to mechanical watches for many women.
Photographs by Senta Murayama
Masamasa Hirota (this magazine): Interview and writing
Text by Masayuki Hirota (Chronos-Japan)
[Article published on January 17, 2025]
First of all, why are there so few mechanical watches for women?
This model is equipped with the new automatic movement, the BVS100 Lady Solotempo, released by Bulgari in 2025. There is also a more practical model with a single-winding bracelet. Automatic (Cal. BVS100 Lady Solotempo). 28 jewels. Power reserve of approximately 50 hours. 18KPG case (35mm diameter). Water resistant to 30m. Price: 8,085,000 yen (tax included).
There are several reasons why there are so few mechanical watches for women. First, they stop immediately when the mainspring unwinds. Second, it's a hassle to pull out the crown and set the time every time. Additionally, they are more complicated than quartz watches, so they are not cheap. When it comes to purely practical items, there's no doubt that quartz watches win out over mechanical watches.
Currently, many mechanical watches use automatic movements, in which a rotor (a semicircular weight) turns to wind the mainspring. To wind the watch, you need to swing your arm to turn the rotor, but for users who mainly do desk work, the rotor tends to not turn enough, resulting in insufficient winding. This is less likely to happen with modern automatic watches, but the inability to wind the watch without proper arm swinging remains a weakness of automatic watches. Additionally, women's automatic watches are smaller in size and cannot have larger, heavier rotors, which means the mainspring is even less wound.
Considering this, it is not surprising that manufacturers have been hesitant to develop automatic watches for women. Even if they did make mechanical watches for women, the best they could do was to change the appearance of a men's model and make do. In my opinion, Rolex, Breguet, Blancpain, and Harry Winston were the only brands that previously had practical automatic movements for women. However, times have changed. Now, Omega, Chanel, and Chopard, among others, have begun to use automatic movements that wind well despite their small diameter. And this year, Bulgari has joined the group. Bulgari is now a manufacturer that produces its own movements, but who would have imagined that they would make an automatic watch for women, which is so difficult to make?
Bvlgari's new automatic movement, the BVS100 Lady Solotempo
This year, Bvlgari announced the BVS100 Lady Solotempo, a completely new automatic movement designed for widespread use. Fabrizio Bonamassa Stigliani, head of design, explained, "When designing the movement, we first considered the size of the barrel (which houses the mainspring)." The reason for this was to maximize the power reserve with as long a mainspring as possible. Despite its small size of just 19mm in diameter and 3.9mm thick, the watch boasts an impressive 50-hour power reserve. Typically, women's movements of this size only have a power reserve of around 40 hours. However, Bvlgari has given the watch a long enough running time that it won't stop even if left alone for a weekend.
Another key feature is its large "heart." A major factor in determining the accuracy of a mechanical watch is a component called the balance wheel. The larger it is, the more accurate the timekeeping, but if it's too large, it loses a lot of energy. However, by revising the design and reducing the resistance of the components, the BVS100 Lady Solotempo is now able to have a large balance wheel that takes up roughly half of the movement. Furthermore, by changing the component that supports the balance wheel from above (called a bridge) to one that supports it on both sides, shock resistance has also been improved.
The automatic winding mechanism is also new. Currently, many women's automatic watches use a unidirectional winding system, in which the rotor rotates in one direction to wind the mainspring. While this is highly efficient, it causes the rotor to spin freely when the mainspring is not being wound, resulting in unpleasant vibrations and noise. While this has been reduced in current automatic watches, it is difficult to completely eliminate. In terms of feel, the ideal system would be a bidirectional winding system, in which the rotor rotates in both directions to wind the mainspring, but this is only used by a few manufacturers. In fact, Rolex, Omega, Grand Seiko, and Chanel are the only small automatic watches for women that use a bidirectional winding system. This time, Bulgari has adopted a bidirectional automatic winding system.
It is said to be technically difficult to incorporate a bidirectional automatic winding mechanism into a small movement. While it would be possible to do so by increasing the weight of the rotor that winds the mainspring, this is difficult to incorporate into a small women's movement. Even if it were possible, it would inevitably increase the thickness and make the watch look ungainly. In contrast, Bulgari has succeeded in adding a bidirectional automatic winding mechanism to the thin and small BVS100 by making the rotor out of a heavy tungsten alloy and molding it as a single piece. Looking at the thin rotor, it's easy to see why Bulgari CEO Jean-Christophe Babin boasted, "We aimed to design it to look thin."
This movement also has been designed with care to prevent even users unfamiliar with mechanical watches from breaking it. One such consideration is the hand-setting mechanism used to set the time. The parts known as the mandarin duck and lashings are significantly larger than the size of the movement. Therefore, even if the crown is roughly pulled out, there will likely be little damage to the movement. The corners of the crown have also been carefully rounded off to make it easier to turn. This is a consideration typical of Bulgari, a brand accustomed to making women's watches.
The BVS100 Lady Solotempo is worthy of being called a new era of automatic watches for women. Moreover, this movement is not exclusive to Bulgari. According to the company, "In the future, this movement will be produced by Zenith (a member of the same group)." This means that Zenith, Hublot, TAG Heuer, and Tiffany, all of which belong to the same LVMH group as Bulgari, could potentially use the BVS100 Lady Solotempo. While this is merely a possibility, if all LVMH group companies were to use this excellent automatic movement, mechanical watches could suddenly become more popular among women. The BVS100 Lady Solotempo was released in secret, but in fact, it is a movement full of potential.
The Serpenti Seduttori features an automatic movement. As if to demonstrate Bulgari's commitment, seven models were released at once. Automatic movement (Cal. BVS100 Lady Solotempo). 28 jewels. Power reserve of approximately 50 hours. Stainless steel (left) and 18K yellow gold (right) cases (34mm diameter). Water resistant to 30m. (From left) 1,573,000 yen and 5,698,000 yen (both including tax).
A new movement with the potential to change the face of women's mechanical watches
The new automatic BVS100 Lady Solotempo boasts high performance that is unusual for a women's watch. If it becomes popular, it could dramatically change the nature of women's mechanical watches. This movement is so full of potential for the future.
