The most extreme example of the ultra high-end brand’s minimalist approach was probably seen in the RM UP-01 Ferrari which was launched back in 2022 to claim the title of ‘world’s thinnest mechanical watch’ at a wafer-like 1.75mm thick (pipped two years later by Bulgari’s Octo Finissimo Ultra, 0.05mm slimmer…).
The 30 gram RM UP-01’s movement weighed-in at a mere 2.82 grams which, to demonstrate just how absurdly light that is for a mechanical object, is equal to three US dollar notes (although the price of the watch at launch was a rather more substantial $1.88m….).
From Record-Breaker to Daily Wearer
As an example of extreme horology it remains remarkable, but Richard Mille has now produced a far more practical ‘daily wearer’ that should satisfy all but the most obsessive horophile’s lust for lightness while also being a whole lot more practical and wearable than the UP-01.
Although the new RM55-01 might seem like a positive lump compared to the wafer-thin UP, its all-up weight of around 66 grams still only equates to that of a tennis ball.
Engineering Lightness from the Inside Out
At 37.95mm wide, 10.75mm thick and 47.33mm long, its would be considered on the large size were it by any other maker – but Richard Mille describes the dimensions as ‘conservative’ and the three-part case is offered in three bezel versions: Carbon TPT, White Quartz TPT and Grey Quartz TPT.
The top flange, meanwhile, is made from grade 5 titanium, the lower ones from polyamide with a touch of steel, and the crystals measure a mere one mm (front) and 1.5mm thick (back), serving as superb windows that allow plenty of light in to illuminate its sub five gram movement – which, being hand-wound, has no heavy oscillator to add bulk or obstruct the view.
Beyond that, the mechanism is designed to fit the case precisely and is built on a microblasted, black PVD-coated baseplate of grade 5 titanium set on rubber ‘shock absorbers’ and with its going train held in place by a trio of titanium bridges finished in Titalyt (achieved by electro-plasma oxidation).
The regulating system, which is usually adjusted by the length of the hairspring, is replaced on the RM 55-01 by a quartet of minuscule, movable weights that regulate by altering the inertia of the balance wheel in order to ensure optimum accuracy of the 4Hz/28,800 vph movement .
The watch also offers hacking seconds, 50 metre water resistance, an impressive 55 hour power reserve and Richard Mille’s ‘double barrel’ system in which twin winding barrels offer more stable torque distribution - again contributing to enhanced accuracy.
It’s often said that Richard Mille watches are bought largely as status symbols but, while the RM55-01 certainly isn’t cheap, it is in no way ostentatious and should appeal more to buyers who really appreciate micro-mechanical art than those who want to demonstrate extreme wealth.
As an object of understated technical excellence, we have to award it 10 out of 10 – not least because of the way it wears its brilliance.
Which is, of course, ‘lightly’….
The Richard Mille RM55-01 costs CHF 155,000 plus VAT.
