An aluminum case, an aluminum bracelet and an aluminum movement produce a watch that weighs almost nothing and contains one of the most complicated chronographs anybody builds. The Centigraphe Sport was the first attempt to put the hundredth of a second mechanism into something that could be worn hard, and the aluminum version is the extreme end of it: 42 mm across, with rubber bumpers set into the case and a dial cut from the same alloy. It is long out of production and was replaced by the 44 mm LineSport generation. Nothing since has been this light. The generation ran alongside a titanium version built to the same drawing.
The whole construction is built around removing mass. The case and the bracelet are aluminum alloy, anodized rather than plated, with rubber inserts at the flanks that take impact and keep the metal off the wrist. The dial is the same alloy, so the watch is effectively one material from the outside in. Three counters are cut in sapphire and set into it, which is how the layout stays legible on a surface that cannot be finished the way silver can, and the indexes and numerals are applied rather than printed so they stand clear against a matte ground. At 42 mm the case is a size the collection no longer uses, sitting between the 40 mm dress watches and the 44 mm sports ones. Assembled with the bracelet the watch weighs well under a hundred grams. Anodizing is what gives the case its color and also its vulnerability, since the layer is thin and a deep mark goes through it rather than into it. That is the trade for the weight. Journe accepted it because the watch was conceived as an experiment in how light a serious mechanical chronograph could be made, and every decision follows from that. Rubber, aluminum and sapphire are the only three materials on the outside of the watch, and none of them is there for appearance.
The movement is where the argument was really made. Journe built the chronograph in aluminum alloy rather than in brass or gold, which is not something the industry does, on the grounds that a sports watch has no reason to carry a heavy mechanism it will never display in a dress context. That decision saves more weight than the case does. Everything else about the chronograph is unchanged: three counters, a hundredth of a second hand turning once a second and stopping anywhere on its path, a twenty second register and a ten minute one, all fed from the center of the mainspring so the timekeeping is left alone. Operation is by the rocker in the case band, which is easier to reach on a sports watch than two pushers would be and was the reason the mechanism transferred so cleanly. An aluminum movement is also a maintenance question that has no equivalent elsewhere in the collection. The alloy is harder to work than brass, does not take the same finishing, and behaves differently under temperature, all of which Journe had to solve before the watch could be sold. No other maker has attempted a chronograph on this principle in this material. The finishing through the sapphire back is done to the same standard as the gold movements, which on a metal chosen for lightness is a decision nobody asked for.
The Centigraphe Sport was the beginning of the sports line rather than a variant of the dress watch. Journe built it before the family had a name, and the Octa Sport in aluminum followed it in 2012 using the same thinking applied to an automatic. Both were retired when the collection was rebuilt in 2018 at 44 mm in grade 5 titanium with a ceramic bezel, which is the form the LineSport takes today. That leaves the aluminum generation as a closed chapter and a distinctly different object from what replaced it: lighter, smaller, more experimental, and finished in a way the house has not returned to. Aluminum has not appeared on a case since. The reason is straightforward enough. Titanium does everything aluminum does apart from the last few grams, and it does it without anodizing, which means a case that survives ordinary use rather than showing every contact. Journe made the switch when the line was rebuilt and has not revisited it. That leaves the aluminum watches as the only examples of an idea the house tried once, which is the sort of thing that matters more to collectors than to owners. The bracelet was unique to this version as well and was never offered in another metal, which means a complete watch and a complete bracelet have to be found together rather than assembled later.
This appeals to somebody who wants the first version of an idea rather than the refined one. It is the lightest watch Journe has made and probably the lightest chronograph of this complexity anybody has made, and the experience of putting it on is genuinely strange for that reason. Against the current titanium version it gives up robustness, since anodized aluminum marks where titanium absorbs, and it gives up the ceramic bezel. As a discontinued reference the questions are condition of the case and the rubber inserts, which perish and are the part most likely to need attention, and completeness of the bracelet. The chronograph should be run through several cycles before anything else. A hundredth hand that hesitates on reset is the fault to watch for, and on this movement any work has to go back to the manufacture. Case condition is the other variable, and buyers should expect marks rather than hope for none, since an anodized aluminum sports watch that has been worn will show it, and a clean example is unusual.
