The Bulgari Octo Finissimo Tourbillon Watch was introduced in 2014, and, at the time, it was the thinnest tourbillon movement ever made, at only 1.95mm thick. The skeletonized version, introduced this year, lets you look inside that movement and get a better idea of how the Bulgari men’s watch manages to be so thin, while at the same time offering slickly cool visuals to go along with the faceted Octo case.
If you’re interested in ultra-thin tourbillons, it’s a good time to be alive. There have been several interesting ultra-thin tourbillons released in the last few years, including the Breguet Classique Tourbillon Extra-Thin Automatic 5377, which has a movement only 3mm thick, and the Arnold & Son UTTE Tourbillon, whose movement is 2.97mm thick. The record for the thinnest tourbillon wristwatch ever made was set by Audemars Piguet, back in 1986, with the caliber 2870 – the entire watch was only 4.8mm thick, although this was achieved by using the caseback itself as the movement plate. (If you’re interested in where the idea to use the case as the movement plate came from, there’s more in Part 3 of our in-depth look at the history of ultra-thin watchmaking.) The Bulgari Octo Finissimo Watch is, as far as I know, the thinnest tourbillon wristwatch, as well as the thinnest tourbillon movement, ever made using the conventional approach of a separate movement and case, although, as we’re going to see, the movement itself is pretty unconventional.
The Bulgari Octo Finissimo Skeleton Tourbillon is the world’s thinnest hand-wound tourbillon movement and watch.
One of the most interesting characteristics of the movement is that it does away with the traditional plate-and-bridges construction found in virtually all other movements. Basically, most of the gears are “flying” gears (that is, they’re secured in only one pivot, instead of two) and the gears for the keyless works for winding and setting are on the same level as the rest of the gear train. It’s not the most extreme movement in terms of putting everything on a single level – that honor probably goes to Piaget’s caliber 900P, which manages the trick of suppressing the hands and dial to the level of the going train and keyless works as well – but it’s still a pretty radical departure from conventional movement construction.
The 5mm thick platinum case has a total of 110 different facets.
The second major contributor to the thinness of the watch is the use of ball bearings. In the Bulgari Octo Finissimo Tourbillon’s caliber BLV268SK, there are a couple of places you can see ball bearings in action; there are visible ceramic ball bearings supporting the flying tourbillon, and you can also see, through the sapphire caseback, three ball bearing–mounted rollers, supporting the mainspring barrel.