Tudor Shrinks the Black Bay Chrono With the New 39mm "Bumblebee"

Tudor just released the Black Bay Chrono 39 "Bumblebee," reference 79310N, a black-and-yellow chronograph that answers a request collectors have been making for years. It arrives in a 39mm case, the first time the Black Bay Chrono has worn anything other than 41mm.

A smaller case, the same movement

Obviously, the yellow dial grabs your attention first. Tudor slots the Bumblebee into its Daring Watches collection, alongside the Pink and Flamingo Blue chronographs, so color is really the hook here. But for enthusiasts and Tudor collectors, the redesigned case is the real story.

Every version since the 2017 original has run 41mm across and 14.4mm thick, which is a lot of watch. Consider those measurements alongside the modern Rolex Daytona, listed at 40mm but really 38-39mm in diameter and about 12mm thin. The Bumblebee drops to 39mm and 13.1mm. Even a tenth of a millimeter can change how a watch feels, so shedding more than a full millimeter here is a big deal.

Tudor managed that reduction by reworking the case construction rather than opting for a thinner caliber, so the Bumblebee keeps the Manufacture Calibre MT5813 and its 70-hour reserve. That movement has powered Tudor's chronographs since 2017, built on Breitling's B01 architecture with a column wheel, vertical clutch, silicon balance spring, and COSC certification. The architecture is older now, but that hardly counts against it. This remains one of the best chronograph movements you can get under $8,000, so keeping it going is a welcome decision; if it ain't broke, don't fix it.

The supporting changes line up with the new proportions. The Snowflake hands have been redesigned for better legibility against the sub-counters, the pushers wear a new knurling pattern, and the watch ships on a fresh three-link bracelet with smooth-sided links (not faux rivets) and Tudor's T-fit clasp. Water resistance stays at 200m, and the pushers remain screw-down.

The crown has changed too, and I think it is one of the better updates. On earlier Black Bay models, the coin-edge crown screwed down onto a sort of tube that stuck out from the case; here it sits flush against the case side with no visible tube, and the knurling is coarser. Some collectors are already saying they preferred the older crown, and I understand the attachment, but the flush version looks cleaner to me and suits a watch built around tighter proportions.

My take

This looks close to the exact Tudor chronograph I have been waiting for. I have always liked the Black Bay Chrono for its overall design, movement, and water resistance. While the full-size model fits on my wrist, it's big enough that I probably wouldn't reach for it every day. The Bumblebee addresses the dimensions without touching that awesome movement.

Tudor made a similar move going from the 41mm Black Bay to the Black Bay 58, shrinking a popular watch into dimensions that suit more wrists. I'm excited to see the Black Bay Chrono 39 inevitably receive more color options (and maybe a five-link bracelet), but I personally love the yellow dial. I recently owned a yellow Doxa Sub 200T that I also referred to as the bumblebee. A bucket list watch of mine is the yellow-dial Rolex Oyster Perpetual 41 ref. 124300. The Tudor Bumblebee is up my alley personally.

At $6,725, it asks the same as the rest of the line, which seems fair. Again, this is a world-class chronograph movement, based on Breitling's B01 architecture, and for reference, the cheapest B01-based watch Breitling offers is the Avenger B01 (on a fabric strap) for $7,150. For less than $7,000, you can get this new Tudor Bumblebee — a 200m water-resistant chronograph from a renowned Swiss brand with an excellent movement.