OMEGA Speedmaster '57 332.10.41.51.01.001: specs and what to check

Hand-wound, and sixty hours

OMEGA specifies the calibre 9906 as manual-winding with 60 hours of power reserve.

Those two facts do not usually travel together. Hand-wound chronographs are commonly good for two days at most; sixty hours means a watch wound on Friday morning is still running on Sunday evening.

For the buyer, that is the practical argument for the reference: the ritual of winding without the penalty of a watch that stops every time you skip a morning.

For you, it is a test. Wind it fully, set it down, and check it sixty hours later. A movement that gives up at forty is telling you about its barrel.

The most informative thirty seconds

Because there is no rotor, winding this watch puts your fingers directly on the condition of the mainspring and the winding train — information an automatic hides behind a slipping bridle.

Start from stopped and turn the crown steadily, watching three things.

Evenness. The load should stay level throughout. A stretch that abruptly slackens, or one that bites harder than the rest, is worth noting.

Progression. Tension ought to build as the spring fills, ending at a firm, unmistakable halt.

Repeatability. Do it twice; the number of turns needed should match.

And then the warning that matters more than the test: when it stops, stop. A manual mainspring has nothing to protect it from someone who keeps turning. Plenty of buyers have only owned automatics and will do exactly that. Say so at handover, and check on inspection whether a previous owner already learned it the hard way.

Fifty metres on a watch that looks tougher

The rating is 5 bar (50 metres / 165 feet).

Every cue on this watch argues otherwise. It is a chronograph, it is steel, it is on a bracelet, and the name carries fifty years of association with instruments.

Fifty metres is rain and hand washing. Not swimming, not showers, not washing up.

Put it in the listing in words rather than leaving it as a number in a table. This is the specification most likely to generate a complaint on a watch of this kind, and one sentence prevents it.

Size, honestly

40.5 mm across sounds modest. 49.64 mm lug to lug does not.

The span is over nine millimetres longer than the case is wide, which is a lot, and it is the figure that decides whether the watch sits properly on a given wrist. Quote it alongside the 12.99 mm thickness and the 134 g weight, and let the buyer decide with the same information you have.

Lug width is a usefully ordinary 20 mm, so strap changes are easy — worth mentioning, because several other references documented here are not.

The crystal is sapphire treated on both faces, so inspect the outer coating for wear as well as checking for haze behind the glass. The clasp is a foldover with comfort setting: run the micro-adjustment through its detents and confirm it holds under load.