RM 055 BUBBA WATSON 555.45B.91-1
Richard Mille RM 055 BUBBA WATSON 555.45B.91-1 Watch: This watch features a manual winding Skeleton Movement with hours, minutes and seconds; inspired by calibre RM UL1.
Herald at their intial release in 2001 as a break from the past and a new direction of horology, the wristwatches of Richard Mille were from their very inception, extraordinary and uncompromising.
TECHNICAL SPECIFICATIONS FOR THE RICHARD MILLE RM 055
BUBBA WATSON
Available in rubberized grade-5 titanium caseband and back with ATZ front bezel.
CALIBER RM UL2: manual winding skeleton movement with hours, minutes
and seconds; inspired by calibre RM UL1.
Dimensions: 49.90 mm x 42.70 mm x 13.05 mm.
Movement weight: 4.3 grams.
MAIN FEATURES
POWER RESERVE
Circa 55 hours.
BASEPLATE AND BRIDGES IN TITANIUM
The manufacturing of these components in grade 5 titanium with black PVD coating for the bottom plate and the bridges gives the whole assembly a great rigidity and achieves excellent surface flatness, essential to the perfect functioning of the gear train. The skeletonised bottom plate and the bridges have been subjected to complete validation tests to optimize their stress resistance.
BALANCE WHEEL WITH VARIABLE INERTIA
This type of balance wheel ensures greater reliability in the event of impact as well as during assembly and disassembly of the movement. This improves precision in the long term. There is no need for an index plate, and it is possible to adjust the
inertia more finely and more frequently directly on the balance wheel using 4 adjustable small weights.
DOUBLE BARREL SYSTEM
The double barrel system helps improve torque stability over a longer period by reducing pressure and wear
on the teeth, bearings and pivots, resulting in improved performance.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES
Their shape allows better control of the torque applied to these screws during assembly. The screws are thus perfectly resistant to manipulation during assembly and disassembly and are exposed to minimal wear and tear.
OTHER FEATURES
- Movement dimensions: 30.25 x 28.45 mm
- Thickness: 3.15 mm
- Number of jewels: 24
- Barrel arbour in 20AP steel
- Balance wheel: GLUCYDUR, 4 arms, moment of inertia 4.8 mg.cm2, angle of lift 53°
- Frequency: 28,800 vibrations per hour (4 Hz)
- Balance spring: Elinvar
- Shock protection: Incabloc 908.22.211.100 (transparent)
- Escapement wheel jewels: Rubifix (transparent)
- Two winding shaft positions: winding and hand setting
CASE
Richard Mille has turned to ATZ for the bezel of the RM 055 BUBBA WATSON case, with a rubberized Grade-5 titanium case
band and back. The ATZ bezel is based on aluminum oxide powder tubes injected at a pressure of 2,000 bar. This high pressure injection increases rigidity by 20-30% and reduces the material's porosity to an absolute minimum. ATZ has the reputation of being a particularly scratch-resistant material (1,400 Vickers), and possessing an unchangeable color. After diamond, it is one of the hardest materials in the world. A long and difficult machining and molding process
using diamond tools is necessary to create the complex form of this bevel, which is given a final matt surface finish. These qualities make this the ideal material for a bezel, an area highly exposed to impact. The case middle and back are in grade 5 titanium with a protective white rubber casing. This is based on the principle of rubber being injected at high pressure around the titanium component. This injected elastomeric isolates and absorbs any vibration. The combination of grade 5 titanium, an exceptionally light and resistant material, with the softness and strength of rubber, makes for very comfortable wearing. The case of the RM 055 is water resistant to 30 metres. It is assembled using 20 grade 5 titanium screws and abrasion resistant washers in 316L stainless steel.
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE CASE
Their shape allows better control of the torque applied to these screws during assembly. The screws are thus perfectly resistant to manipulation during assembly and disassembly and are exposed to minimal wear and tear.
CROWN
In grade 5 titanium with collar in Alcryn.
INTERIOR FLANGES
Flange in black carbon fiber with index points filled with an approved luminescent material. Minute flange in DLC-coated titanium.
CRYSTAL
Bezel side: in sapphire (1,800 Vickers) with anti-glare coating (on both sides).
Thickness: 1.50 mm
Case back: in sapphire (1,800 Vickers) with anti-glare coating (on both sides).
Thickness: 1.20 mm and 2.04 mm at the outer edges
FINISHING
MOVEMENT
- Baseplate and bridges in grade 5 titanium, wet sanded, coated in PVD and with a straight-line
- grain finish after coating
- Hand-polished lock-points
- Burnished pivots
- Pinions with undercuts
- Sandblasted and rhodium-plated bevelled wheels (before cutting the teeth)
- Minimal corrections to preserve the geometry of the wheels and their performance.
STEEL PARTS
- Screw slot and screws bevelled and polished with rounded and polished tip
- Straight-line grain finish of the upper surfaces
- Lower surfaces microblasted
- Hand-polished surfaces
- Hand-polished angles