A self-taught watchmaker who works out of an apartment in Tokyo, Hajime Asaoka has established an impressive track record since he completed his first watch in 2009. Most of his timepieces are tourbillons, including his latest: the Tourbillon Pura. Cleanly styled with a hint of Art Deco, something that characterises many of his designs, the Tourbillon Pura is hand-wound with a one-minute tourbillon regulator and a movement that’s constructed with exactness. The Tourbillon Pura is arguably Asaoka’s best creation to date.
As with last year’s Project T Tourbillon, Asaoka conceived the Tourbillon Pura movement to ensure longevity and a precision fit of all the parts. Unlike most watches that have several bridges on the movement to hold all the moving parts in place, the Tourbillon Pura utilises a single, round bridge. Three large rubies secure the second, third and fourth wheels, the key parts of the gear train that transmits power from the mainspring to the regulator. Because all three wheels are held by a single bridge, their relative position is also perfectly aligned.
For the same reason, the three large screws that hold down the single bridge are positioned equidistant from each other. This prevents distortion of the bridge over time due to excess tightening of the screws.
The single-bridge construction gives the movement a pleasing, symmetrical layout. Three cut-outs in the bridge reveal the second wheel with wavy spokes; Asaoka first used the “octopus” wheel on the time-only Tsunami, with the Patek Philippe minute repeating calibre found in watches like the refs. 5207P and 5539G.
Traditional materials are used for most other parts of the movement: the bridge and base plate are German silver, while the tourbillon bridge is steel. The tourbillon cage, however, is made of Duralumin A7075, an aluminium alloy that is used in aviation and rifles, favoured for its low density and high strength. The same reasons make it a material of choice for the tourbillon cage, since a lighter cage requires less energy to rotate, leaving more energy to power the balance wheel.
Simpler in style than many of Asaoka’s earlier creations, the Tourbillon Pura has a glossy, jet black dial that’s coated with diamond-like carbon (DLC). The coating is applied to the dial and then polished to leave the railway track hour markers flush with the dial. Only the stepped 12 o’clock marker is raised, a detail that’s also found on Asaoka’s other tourbillons. Simple in form, the hands are beautifully finished, with a rounded, polished top.
The case is stainless steel, 40 mm in diameter and 11.5 mm high, making it slightly smaller than Asaoka’s other tourbillons which are mostly 42 mm. Its compact dimensions give the Tourbillon Pura a refined feel in hand, evoking watches from the mid-20th century.
Pricing for the Tourbillon Pura has yet to be announced but comparable tourbillons by Asaoka retail for between ¥7 million and ¥8 million, or about US$65,000 to US$75,000.Back to top.
You may also enjoy these.
Designed and produced almost entirely by one man in a home workshop, the Tourbillon #1 was Hajime Asaoka's first timepiece and proof that is he one of the best emerging independent watchmakers.