If anybody thought the main contenders in the battle for ultra-thin mechanical watches were Bulgari and Piaget, today's news is going to come as a big surprise. Just months after Bulgari's launch of the Octo Finissimo Ultra, the previous world's thinnest mechanical watch with a 1.80mm profile, Richard Mille steps on the accelerator and steals pole position from Bulgari with its mind-blowing 1.75mm thick RM UP-01 Ferrari. However, there is another astonishing fact about the Richard Mille watch, which has to do with its construction. Unlike Piaget and Bulgari's ultra-thin watches, which use the caseback as a baseplate, Richard Mille has assembled the 1.18mm manual-winding movement INSIDE the case. A limited edition of 150 timepieces, the RM UP-01 is the first watch to emerge from the brand's recent alliance with Ferrari.Il SorpassoWho could have seen this coming? In one of the most intrepid and exciting sorpassi (overtaking) in the watch world, Bulgari's 1.80mm thin Octo Finissimo Ultra has been beaten by Richard Mille's hyper-lean machine with a case thickness of 1.75mm. It might just be a 0.05mm difference (about the thickness of a thin human hair), but it has enshrined the RM UP-01 Ferrari?in pole position. Ad - Scroll to continue with article Richard Mille and Ferrari teamed up in 2021, a natural alliance forged by two brands obsessed with precision, reliability and innovation. To celebrate this partnership with Ferrari, RM pushed the envelope to the extreme and created the hyper-flat 1.18mm calibre RM UP-01 in collaboration with the laboratories of Audemars Piguet Le Locle (formerly Renaud & Papi). Working alongside the Ferrari team and following countless prototypes and more than 6,000 hours of R&D and laboratory testing, the Richard Mille RM UP-01 materialised. The extraordinary architecture of the movement – which does not rely on the caseback as part of the movement – is traditional and is assembled inside the case. The reason for incorporating the 41.45mm x 28.85mm calibre inside a case was mandated by shock-resistance and RM's mission to create a watch for everyday wear and tear. What is not traditional is the distribution of the components. Instead of a conventional arrangement of superimposed gears, hands and stacked components, the RM UP-01 conquers its ultra-thin profile with a horizontal distribution of elements. To keep the thickness of the calibre at a minimum, engineers from AP Le Locle and RM developed a new escapement with a balance wheel in titanium. All the components, which have to meet tolerances of a single micron, are machined at RM's movement department. Fitted with a fast-rotating barrel, the power reserve is around 45 hours.Far from being a case study in ultra-thin watchmaking, the RM UP-01 Ferrari?is made to be worn. Grade 5 titanium, a corrosion-resistant and rigid alloy, is used for the baseplate and bridges, conferring the required rigidity and surface flatness for the perfect functioning of the gear train. To ensure the movement can withstand accelerations of over 5,000 G's, the skeletonised baseplate was subjected to extensive testing.The Shape of Thin to ComeThe rounded rectangular shape of the Richard Mille RM UP-01 Ferrari, which measures 51mm x 39mm x 1.75mm, evokes Richard Mille's emblematic tonneau-shaped cases and is secured with 13 titanium spline screws on the case and bridges. Machined from grade 5 titanium, the monobloc case construction optimises rigidity. The front side of the watch, which is actually a large bezel, and the caseback are satin-brushed with polished bevels. The Richard Mille RM UP-01 Time IndicationsObviously, a case this thin cannot incorporate a regular winding crown, and the solution resides in the two hollowed-out crowns' on the left side of the dial/bezel. The first crown' positioned between 10 and 11 o'clock is to select the winding (W) or hand-setting (H) function, while the second crown' between 7 and 8 o'clock is used to set the time or wind the barrel. Both crowns are framed by black ceramic inserts to protect the bezel from friction and ensure the 10m water-resistance.The recessed time indication is placed in the centre of the dial/bezel with red hour and minute hands and is protected by a sapphire crystal, like the balance wheel to the right. Below the time and balance functions is an engraved depiction of Ferrari's Prancing Horse logo.Availability & PriceThe Richard Mille RM UP-01 Ferrari?is limited to 150 pieces and will retail for a quite substantial, to say the least,?CHF 1,700,000?(excl. tax).?For more information, please visit www.richardmille.com.