Fifty-three grams, including the movement, which is also made of aluminum. The Octa Sport Aluminum is the watch where F.P. Journe took a five-day automatic complication and built the entire object out of a metal nobody uses for either cases or calibres. The case is aluminum alloy with rubber inserts, 42 mm across and 11.6 mm deep. The dial is aluminum alloy and sapphire, a combination the manufacture had not used before. The layout is unlike any other Octa: central hours and minutes, small seconds at 6 o'clock, a day and night indication at 9, the power reserve at 10:30 and a large date at 1. It was made between 2011 and 2014 and has not been offered since, and the model that replaced it in the line moved to titanium rather than continuing in this material.
Aluminum is a difficult case material and the difficulties are all in the surface. The metal is soft, it oxidizes readily, and in its raw state it marks if you look at it. What makes a case like this possible is treatment rather than the alloy alone, and Journe's is processed to be scratch resistant, anti-corrosive and anti-allergic before anything is assembled. That converts a metal that would otherwise be unusable into one that behaves acceptably on a wrist, and it is the reason the watch exists at all. The rubber inserts are the other half of the argument. They run into the case rather than sitting on it, absorbing contact at the points most likely to take it and breaking up what would otherwise be a large uninterrupted expanse of gray metal. The result reads as a technical object rather than as a dress watch in a different suit, which is the correct outcome, since a five-day automatic with a large date and a day and night indication would look absurd trying to pass as sporting equipment. Nothing here pretends to be something else. The case is 11.6 mm deep, which is a millimeter more than a conventional Octa and reads as considerably less, because the material gives no weight to support the impression of bulk.
The movement is the part that should stop you, because building a calibre from aluminum alloy is not a thing watchmakers do. Brass is the industry standard and gold is the luxury alternative, and both are chosen partly because they are dense, stable and forgiving to machine. Aluminum is none of those. It is roughly a third the density of brass, which is exactly why it was used here, and that lightness comes with a much softer material that moves more under temperature and wears faster at any bearing surface. Working it to watchmaking tolerances means fighting the metal at every stage, and keeping those tolerances over decades of running means accepting that the wear surfaces will need attention sooner than a brass movement's would. Journe built the Octa's automatic architecture in it anyway: 42 mm of case holding a movement that runs 21,600 alternations per hour, with a balance 10.1 mm in diameter carrying four adjustable inertia weights, unidirectional automatic winding, and a barrel delivering about 160 hours. The complete watch weighs 53 grams. A conventional Octa in platinum is several times that, and the difference is almost entirely the metal rather than the design. Put the two on opposite wrists and the aluminum one effectively disappears, which is a sensation no amount of thinness achieves on its own.
The lineSport collection began in June 2011 with the Centigraphe Sport, which was F.P. Journe's first mechanical wristwatch in aluminum, and the Octa Sport followed as the second model in the line. That sequence matters, and it explains why the Octa Sport looks like a second step rather than a first one. The Centigraphe Sport made the argument that a serious complication could be built this way; the Octa Sport applied it to the manufacture's automatic platform, which is the watch most people would actually put on every day of the week. A sports line from a maker known almost exclusively for platinum and gold dress watches was not an obvious move in 2011, and the collection was received with some suspicion at the time by people who thought it a departure from what Journe was for. That reading has aged badly. The lineSport has run continuously ever since, first in aluminum and then in titanium and steel, and it turned out to be the part of the catalog that answered the question of what a Journe owner wears when not wearing a Journe. The answer, it turned out, was another Journe. This particular execution, the first Octa in the line, closed in 2014 after three years, which is a short run for a model that established a whole direction.
An aluminum case cannot be restored, and that fact should govern the entire inspection. Gold and platinum can be repolished; a treated aluminum surface cannot, because the treatment is the surface and removing material removes the protection with it. Examine the case for scratches through the finish rather than on it, and for any dulling or discoloration that indicates the treatment has been compromised. Check the rubber inserts for hardening, shrinkage or lifting at their edges, since rubber of this age has a finite life and replacements are not a routine service item. Confirm the sapphire elements of the dial are unmarked, and look at the crown and its housing, which take more handling than any other part of a watch built to be worn actively. Weight is a useful authenticity check in itself, since nothing else in the catalog is this light. Then run the movement: the large date at 1 throwing cleanly, the day and night indication tracking the hands correctly, and the reserve at 10:30 descending its full travel over several days.
