Mille's declutchable rotor is a novel workaround to the problem of having too much energy at the disposal of a mechanical watch equipped with an automatic winding system.

Traditionally, this issue has been addressed through the combination of thixotropic lubrication on the barrel wall and a modified mainspring that can slide along the barrel wall to dispel excess energy when the equilibrium viscosity threshold of the lubricant is met. Said another way, once enough pressure is exerted on the barrel wall lubricant it suddenly becomes slippery and the mainspring can glide across it, but when pressure is any lower, friction remains high enough to hold the mainspring in place.

While it works, this latter approach results in an inconsistent power delivery curve. Theoretically, a declutchable rotor should do away with this inconsistency while simultaneously reducing wear in an area of the watch that often needs addressing when it comes time to service. Not to mention, for Richard Mille, any excuse to use "clutch" in marketing material is gold when it comes to his speeds-and-feeds, motorsport-loving client base.