Breitling Chronomat B01 42 AB0134

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The storyWhy this reference matters

The Chronomat name turns up at Breitling in the early forties and did not mean what it means now: it was short for chronographe mathématique, a watch with a slide rule on the bezel meant for engineers and technicians rather than pilots. It was, in fact, the direct ancestor of the Navitimer. The name was then used on and off until the seventies and ended up in a drawer for a good decade.

A commission revived it. In 1983 Breitling developed a chronograph for the Frecce Tricolori, the Italian display team, and out of it came the two things that define the line today: a rotating bezel with raised riders and a bracelet of cylindrical links the French call rouleaux, rollers. The following year that design became the catalogue Chronomat with which the brand marked its centenary, and the name came to mean automatic chronograph.

The eighties Chronomat saved Breitling in the middle of the quartz hangover and for two decades was the watch the house shipped by the lorryload. Then it grew, filled up with variants and lost its outline. It came back in 2020 with a redesigned case, integrated lugs, solid shoulders and crown and pushers set into the profile, and above all with the rouleaux back after years out of production, now with more angular links and a slimmer profile than the original.

SpecificationsThe numbers, in one table

IdentificationHow to tell it apart

The bezel is the signature. It carries raised riders, and the two at fifteen and forty-five minutes are movable: you turn them to mark a start point or a countdown, depending on whether you prefer to count up or down. No other chronograph in the catalogue has them. The bezel is unidirectional and ratcheted, so it should click and must not spin freely.

The rouleaux bracelet is the second identity card: cylindrical links lined up like rollers. The 2020 one is more angular and flatter than the eighties original, so comparing photographs tells you which decade you are looking at straight away. Steel case, 42 mm by 15.1 mm tall — it is a thick watch, make no mistake — with 22 mm lugs tapering to 20, a domed sapphire crystal and twenty bar of water resistance.

Inside is the full Calibre 01, with counters for quarter seconds, 30 minutes and 12 hours, forty-seven jewels, seventy hours of reserve and COSC certification. The base reference AB0134 opens out into many dials — black, blue, silver, copper — and the long suffix is what separates them. Note that there are titanium and two-tone Chronomat B01 42s under different reference trunks. AB0134 is the steel one.

CollectingWhat collectors check

The rouleaux is the first thing to look at and the thing that suffers most. Take it by one end, let it hang and look for play between links: if it fans open or rattles like a chain, the pins are worn and the bracelet loses value on its own account. Look at the underside of the links too, where sweat and rubbing eat the finish before anywhere else on the watch.

Then the bezel riders. They should sit firm in position and turn with the bezel without wobbling; if one moves by itself, it is loose or a part has gone missing, and they are not cheap to replace. Check the ratchet by listening to the clicks through a full rotation. And at 15.1 mm tall the case takes its knocks on the edges: go over the flanks of the integrated lugs, because a bad polish there destroys the crisp lines of the design and shows at a glance.

On the movement, the usual for a column-wheel chronograph: the pushers should answer with a short crisp click and the chronograph hand must return exactly to zero on reset. A jump as the hand starts betrays a misadjusted vertical clutch. Ask for the certificate and the complete box; on a watch this recent, the full set is worth real money at resale.

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Close relativesThe ones it gets confused with