Tudor · Tudor MT5813 chronograph

Tudor Black Bay Chrono and Pelagos FXD Chrono power reserve: inside the MT5813

The Tudor Black Bay Chrono, including the panda dials, the Flamingo Blue and the newer 39 mm model, runs on the MT5813, a Breitling B01-based chronograph that lasts about 70 hours off the wrist. That's just under three days, enough for a weekend in a drawer.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the MT5813

Every Tudor Black Bay Chrono since the first one in 2017 uses the MT5813, and so do Tudor's Pelagos FXD chronographs. It's the only Tudor movement in this family that isn't built on the MT56xx base: it comes from Breitling's B01. The dial layout gives it away: two sub-dials at 3 and 9 o'clock and a date at 6.

Older Tudor chronographs, such as the Heritage Chrono, used outside movements, so this page doesn't apply to them.

Specs at a glance

History and where it came from

Tudor has made chronographs since the Oysterdate Chronograph of 1970, but for decades they used bought-in movements. When Tudor launched the Black Bay Chrono in 2017, it chose not to design its own chronograph from scratch. It took Breitling's B01 through an industrial alliance between the two brands, and Tudor has never been secretive about that.

The B01 was a good starting point: a modern integrated chronograph with a column wheel, which gives a crisp, consistent feel at the pushers, and a vertical clutch, which lets the chronograph run without the seconds hand stuttering on start. Tudor fitted its own balance with a silicon hairspring and variable inertia, had the movement COSC-certified, and called it the MT5813.

The first Black Bay Chrono was controversial. It mixed a dive watch's styling with a racing tachymeter, and critics noted that the big snowflake hour hand can hide the 45-minute counter. In 2021 Tudor updated it with panda and reverse-panda dials and a black bezel insert, and the 79360N became a hit. Since then the MT5813 has gone into colourful editions, a carbon-fibre limited edition, a carbon-composite Pelagos FXD Chrono and, most recently, a more compact 39 mm Black Bay Chrono.

Accuracy in the real world

Each MT5813 is COSC-certified, and Tudor applies its tighter -2/+4 seconds a day standard to the cased watch, as Monochrome's specs for the Black Bay Chrono 39 and Carbon 25 both note. Unlike most of Tudor's three-hand and GMT movements, the MT5813 isn't available as a METAS Master Chronometer.

Owners on watch forums generally report Black Bay Chronos running a few seconds a day fast. Because the chronograph engages through a vertical clutch, the chronograph hand starts without the jump you see on many cheaper chronographs, and it can be left running. As with any mechanical watch, individual examples vary, and one running well outside Tudor's window under warranty is worth sending back.

Reliability and servicing

The B01 architecture has a long track record in Breitling's own chronographs, and there's no widely reported systemic problem with the MT5813.

• Warranty. Tudor's current guarantee lasts five years.
• Servicing. A chronograph has many more parts than a three-hander, and Tudor's network is the normal route. It's more involved, and usually more expensive, than servicing a time-only Black Bay.
• Independents. Parts for manufacture chronographs are hard for independents to get, so fewer will take one on.

Quirks worth knowing

• Screw-down pushers. For 200 m water resistance, the pushers screw down. You have to unscrew them before timing anything, and screw them back before swimming.
• The snowflake hand. The large hour hand can cover the 45-minute counter at some times of day.
• 45 minutes, not 30 or 60. The minute counter runs to 45, a football-match layout.
• Thickness. At 7.23 mm, the movement makes the 41 mm Black Bay Chrono about 14.2 mm thick. The 39 mm version gets down to 13.1 mm.
• Chronograph and reserve. Running the chronograph uses some extra energy, so if you leave it running for long periods, expect the watch to stop a bit sooner than 70 hours.
• Date. As with most date movements, don't change the date by hand around midnight. Here's why.

How it compares

• Valjoux 7750: the traditional Swiss chronograph workhorse. Easy to service, but only about 42 hours, with a cam instead of a column wheel and a less refined start.
• TAG Heuer 02: a close rival with a column wheel, vertical clutch and a longer 80-hour reserve, in the Carrera and Monaco.
• Omega 9900: a co-axial Master Chronometer chronograph with 60 hours, in the Speedmaster Racing and other Speedmasters.
• Rolex 4130: the previous Daytona movement, with 72 hours, also column wheel and vertical clutch, at a much higher price.
• Zenith El Primero 400: the famous high-beat chronograph at 5 Hz, with about 50 hours.

Living with the 70-hour reserve

Seventy hours is generous for a chronograph. Take your Black Bay Chrono off at 6pm on Friday after a full day's wear and it's still running at about 4pm on Monday, with the date right. Many chronographs, 7750s included, would have stopped on Sunday.

It still won't last a week. If your Black Bay Chrono sits in the drawer while you wear a Black Bay 58 on holiday, it will stop by the third afternoon, and a date chronograph is fiddly to reset. Give it a full crown wind before putting it away. Watch Winder counts down this 70-hour reserve for each watch you own and reminds you before it stops. To check a specific gap, try the "Will my watch stop?" calculator.

Verdict

The MT5813 is a strong movement at the Black Bay Chrono's price: a column-wheel, vertical-clutch chronograph with 70 hours, a silicon hairspring and COSC certification, built on the proven Breitling B01. It isn't a Tudor design from scratch and it isn't METAS-certified like Tudor's newer three-handers. The screw-down pushers and snowflake hand take some getting used to. For a daily-wear chronograph that survives a weekend off the wrist, it's hard to beat at the price.

FAQ

How long does a Tudor Black Bay Chrono run off the wrist?

About 70 hours from a full wind, just under three days. If it was only partly wound, or the chronograph was left running, it will stop sooner.

Is the Tudor Black Bay Chrono movement made by Breitling?

The MT5813 is based on the Breitling B01. Tudor adds its own silicon balance spring and variable-inertia balance and has it COSC-certified.

How accurate is the Tudor Black Bay Chrono?

The movement is COSC-certified, and Tudor regulates the finished watch to within -2/+4 seconds a day.

Does the Tudor Black Bay Chrono hack?

Yes. Pulling the crown to set the time stops the running seconds, and the movement can be wound by hand.

Can I leave the chronograph running on my Tudor Black Bay Chrono?

Yes. The vertical clutch is designed for it and won't harm the movement, though running the chronograph uses some extra power and slightly shortens the time before the watch stops.

What is the power reserve of the Tudor Black Bay Chrono 39?

The 39 mm Black Bay Chrono uses the same MT5813 and is rated at 70 hours.

Why do I have to unscrew the pushers on my Tudor Black Bay Chrono?

The pushers screw down to keep the watch water-resistant to 200 m. Unscrew them to use the chronograph and screw them back before getting it wet.

Sources

• Monochrome: 2021 Tudor Black Bay Chrono 79360N with panda dials
• Monochrome: Tudor Black Bay Chrono S&G champagne dial 79363N
• Monochrome: Tudor Black Bay Chrono 39 Bumblebee 79310N
• Monochrome: Tudor Pelagos FXD Chrono Cycling Edition 25827KN
• Monochrome: Tudor Black Bay Chrono Carbon 25 79377KN

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 18 hours of wear fills the Tudor MT5813 chronograph. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 70 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

All Tudor movements · Other 70-hour movements

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the Tudor MT5813 chronograph: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.