Smaller, prettier and just as enduring: the Hublot Big Bang Meca-10 42mm
Jamie WeissThese days, we’re used to seeing mechanical watches with 70-hour-plus power reserves, but ultra-long power reserves are still something of a niche offering. That’s a shame, as they’re arguably one of the most useful features a watch can have. However, a big power reserve often means a big watch. That’s why the new Hublot Big Bang Meca-10 42mm, just unveiled at this year’s edition of LVMH Watch Week, is so interesting, as it represents one of the most wearable watches with an ultra-long power reserve – opening up one of Hublot’s most interesting watches to smaller wrists.
Some background
Hublot is something of a specialist when it comes to ultra-long power reserves, with the iconoclastic brand holding the record for the watch with the longest power reserve from 2013 to 2019 with the MP-05 LaFerrari, which has a whopping 50-day power reserve thanks to an impressive 11 mainspring barrels in series (as well as a gargantuan 51mm diameter).
In 2016, Hublot introduced its Meca-10 movement, which has become one of the brand’s cornerstone in-house movements. As its name implies, it boasts a 10-day power reserve and has long represented one of the most accessible ultra-long power reserve movements on the market. Initially housed inside a Big Bang, the Meca-10 has found its way into other timepieces in the Hublot range, including the Spirit of Big Bang as well as the quirky Arsham Droplet pocket watch and even a 20cm-wide desk clock produced in collaboration with L’Epée.
The case
The headline here with the Hublot Big Bang Meca-10 42mm is its smaller case diameter – specifically, it’s 3mm smaller than the extant Big Bang Meca-10 model, which measures 45mm. At 13.9 millimetres thick, it’s also .6 millimetres thinner than the Big Bang Meca-10 45mm – and, as a point of comparison, is around a whole millimetre thinner than an automatically-winding Big Bang Unico 42mm.
This 42mm collection has launched with three different case options: titanium, forged carbon fibre, and 18-karat King Gold, Hublot’s proprietary red gold alloy. The forged carbon model is particularly notable as it’s the first of its kind to join the core Big Bang collection, and in my opinion, is the pick of the litter.
Otherwise, this is the Big Bang case you’re probably familiar with, with a central portion made from a hard-wearing composite sandwiched by a titanium/King Gold/carbon bezel and caseback, secured by the functional screws that define this watch’s bezel. The titanium and King Gold models have brushed bezels and lugs with polished bevels, while the carbon model has a uniformly matte finish.
The dial
Like previous Meca-10 models and indeed most Hublots, the Big Bang Meca-10 42mm features a skeletonised dial that’s more opened-up than previous Meca-10 models. We’ll get onto the technical details of this watch’s new HUB1205 movement in a second – I don’t want to get too ahead of myself – but Hublot has re-arranged the layout of the Meca-10 movement a bit compared to the HUB1201 found in the Big Bang Meca-10 45, with the power reserve indicator moving to 3 o’clock. What this also does is reveal more of the second of the movement’s two barrels from the dial side.
While the bridges of this new movement lack the circular perforations found on other models, it still retains a distinct Meccano-like charm, with the Meca-10’s signature and unusual “crémaillère” system (i.e. the rack and pinion that drives the power reserve indicator) still having pride of place at 12 o’clock.
The movement
So, to the meat of this watch: its new calibre HUB1205. Hublot hasn’t just made the Meca-10 smaller and thinner, but they’ve also made it prettier. Not only is its layout more pleasing to the eye and more opened-up compared to the HUB1201, the HUB1205 is also finished to a higher standard, with the bridges of the movement now brushed with polished bevels rather than just having matte DLC over right-angled edges.
Like the HUB1201, the HUB1205 is manually wound and, as you might have guessed, has a 240-hour or 10-day power reserve. Actually, Hublot explains that the HUB1205’s full power reserve exceeds 10 days, but they cap its power reserve indicator at that number as that’s the range of optimal chronometric performance (although to be clear, the HUB1205 and the Big Bang Meca-10 42mm range aren’t chronometer-certified).
It’s worth elaborating on that point, as it gets to the heart of why ultra-long power reserves are such a desirable feature for a watch. First of all, while I think winding a mechanical watch is an enjoyable ritual, most watch owners will agree that having to readjust the time after you haven’t worn your watch for a while is a bit of a hassle. The less often you have to do that, the better. However, the other big advantage of a hefty power reserve is improved isochronism.
Essentially, a mainspring delivers high torque when fully wound, then settles at a median level for most of its running time, before dropping off as it fully empties. It’s these variations in torque that affect the accuracy of a movement: you want it in its median sweet spot for as long as possible, hence the value of a longer power reserve. These fluctuations are more pronounced for big barrels – which is why Hublot opted for two smaller barrels instead of one big one in its Meca-10 movements – and by capping and regulating its manual winding, they can keep it in that sweet spot for longer.
This is all to say that the Meca-10 movement is quite clever, and it’s laudable that Hublot’s been able to slim it down to fit into a significantly smaller watch. The HUB1205 is an upgrade in basically every way over the HUB1201 – while I’m impressed by its smaller size and technical aspects, its improved finishing is particularly nice to see.
The strap
The Hublot Big Bang Meca-10 42mm comes mounted on either an integrated black rubber strap for the titanium and King Gold models, or a black Velcro strap for the carbon model. All models utilise Hublot’s One Click strap system, which makes it easy to customise with different Hublot straps. (Note: for our photoshoot with the Big Bang Meca-10 42mm collection, we reviewed the titanium model on a Velcro strap and the carbon model on a rubber strap: the titanium retails with rubber and the carbon retails with Velcro only, but both strap options can be purchased separately.)
The verdict
I’m going to make a bold call: the Hublot Big Bang Meca-10 42mm is the best mainline Big Bang model yet. Not only are its proportions much more wearable than any other complicated Big Bang, but it’s also one of the most visually appealing watches Hublot has ever made. And who else offers a 10-day power reserve at this price point? I’ve long been of the opinion that people have been sleeping on the Meca-10: maybe, with a less chunky watch, people will wake up now.
Hublot Big Bang Meca-10 42mm pricing and availability
The Hublot Big Bang Meca-10 42mm collection will be available from January 2025. Price: US$23,000 (titanium), US$27,400 (carbon), US$42,700 (King Gold)
Brand | Hublot |
Model | Big Bang Meca-10 42mm |
Reference Number | 444.NX.1170.RX (titanium) 444.QN.1170.NR (carbon) 444.OX.1180.RX (King Gold) |
Case Dimensions | 42mm (D) x 13.9mm (T) |
Case Material | Titanium Forged carbon 18k King Gold |
Water Resistance | 100 metres |
Crystal(s) | Sapphire front and back |
Dial | Skeletonised |
Lug Width | Integrated |
Strap | Black rubber with case-matching deployant buckle (titanium, King Gold) Black fabric with Velcro fastener (carbon) |
Movement | HUB1205, in-house, manual-winding |
Power Reserve | 240 hours |
Functions | Hours, minutes, small seconds, power reserve indicator |
Availability | From January 2025 |
Price | US$23,000 (titanium) US$27,400 (carbon) US$42,700 (King Gold) |