Tudor has given the Black Bay Chrono the size correction many collectors have been waiting for.
The new Black Bay Chrono 39 “Bumblebee” keeps the technical backbone of the larger model, but moves into a more compact 39mm stainless steel case with a bright yellow dial and black registers.
It’s a playful turn for one of the strongest value propositions in modern mechanical chronographs, and importantly, the downsizing doesn’t come at the expense of the movement or the watch’s practical credentials.
At a glance
- Tudor has introduced the Black Bay Chrono 39 “Bumblebee” with a smaller 39mm case and vivid yellow-and-black dial.
- The watch retains the automatic MT5813 chronograph movement with column wheel, vertical clutch, silicon hairspring and 70-hour power reserve.
- It is regular production, available now through Tudor boutiques and authorised retailers, priced at CHF 5,500.
A smaller Black Bay Chrono with louder colour
The key change is immediately practical.
Where the existing Black Bay Chrono measured 41mm across and 14.2mm thick, the new Black Bay Chrono 39 comes in at 39mm and 13.1mm thick.
That may not sound dramatic on paper, but chronographs wear larger than simple three-hand watches, and the reduction should make the model a more natural fit for a wider range of wrists.
Tudor hasn’t introduced the new size quietly.
The “Bumblebee” uses a saturated yellow dial with black sub-dials, black hands and black applied dot markers, giving the watch a sharper and more graphic personality than the familiar monochrome Black Bay Chrono references.
The Snowflake hour hand remains, though it has been shortened to reduce interference with the chronograph registers.
Grade A Swiss Super-LumiNova fills the hands and markers, preserving the high-contrast legibility that the colourway promises in daylight.
Rugged case details stay in place
The stainless steel case is fitted with an anodised aluminium bezel insert, a sapphire crystal, screw-down crown and screw-down pushers.
Water resistance remains 200 metres, which is still unusually robust for an automatic chronograph in this price bracket.
The pushers also get a subtle enthusiast detail through revised knurling that nods to Tudor’s Mk II Series 7100 chronographs of the 1970s.
It’s the kind of small historical cue Tudor tends to handle best, visible enough for those who know the archive without turning the watch into a costume piece.
The stainless steel bracelet is equipped with Tudor’s T-fit clasp, allowing tool-free micro-adjustment across five positions and up to 8mm of range.
That matters on a sports chronograph, especially one designed to be worn through warm weather, travel and daily changes in wrist size.
The MT5813 remains the serious part
The movement is where the Black Bay Chrono continues to justify much of its reputation.
Inside is the automatic calibre MT5813, a Breitling B01-derived chronograph movement adapted with Tudor’s own free-sprung balance, adjustable inertia weights and silicon hairspring.
It runs at 4Hz, offers a 70-hour power reserve and uses a column wheel with a vertical clutch.
Those are the headline specifications, but the engineering is more interesting than a quick list suggests.
The running seconds display at 9 o’clock is driven directly by the fourth wheel, while the vertical clutch sits at the centre of the movement.
Between them is a LIGA-fabricated intermediate pinion designed with split teeth that can flex slightly to reduce backlash, helping the central chronograph seconds hand start cleanly and remain stable while running.
The reset system is also carefully considered.
A patented self-adjusting hammer arrangement allows the hammer to settle cleanly against the heart cams during reset, helping both counters return to zero with consistent force.
The calibre is COSC-certified, but Tudor regulates the completed watch to a tighter -2/+4 seconds per day standard.
While this model is not positioned as a Master Chronometer, the silicon hairspring gives the regulating organ meaningful resistance to the magnetic fields that are part of daily modern life.
Details & Specifications
| Brand | Tudor |
|---|---|
| Model | Black Bay Chrono 39 “Bumblebee” |
| Case size | 39mm x 13.1mm |
| Case material | Stainless steel with anodised aluminium bezel insert |
| Crystal | Sapphire |
| Dial | Yellow with black registers |
| Hands and markers | Black, filled with Grade A Swiss Super-LumiNova |
| Movement | Automatic calibre MT5813 |
| Functions | Hours, minutes, small seconds, date and chronograph |
| Chronograph construction | Column wheel and vertical clutch |
| Frequency | 4Hz, 28,800vph |
| Power reserve | 70 hours |
| Water resistance | 200 metres |
| Bracelet | Stainless steel bracelet with T-fit clasp |
| Price | CHF 5,500 |
| Availability | Regular production, available now at Tudor boutiques and authorised retailers |
The Black Bay Chrono 39 “Bumblebee” is not just a new dial colour on an existing formula.
By shrinking the case while preserving the movement, water resistance and bracelet adjustability, Tudor has made one of its most compelling chronographs easier to recommend, especially for collectors who liked the idea of the Black Bay Chrono more than its previous proportions.
