RM055 Bubba Watson

The new RM 055 Bubba Watson is inspired by the RM 038 Bubba Watson tourbillon watch presented in
2011. Its mechanical movement in grade 5 titanium displays extreme skeletonization, with a PVD- and
Titalyt® treated baseplate and bridges. This combination provides the whole structure with optimum
rigidity and excellent surface flatness and finish, essential aspects for the perfect functioning of the
gear train. The caliber RMUL2 is thus capable of withstanding accelerations of over 500-G’s.
The movement is equipped with a variable-inertia balance wheel, which ensures reliability in the event
of impacts and during assembly and dismantling, thus improving the long-term accuracy of the
timepiece. The regulator index is eliminated, and a more accurate and repeatable inertia adjustment
is possible thanks to four small adjustable weights located directly on the balance wheel. The doublebarrel
mechanism helps to improve and equalize long-term torque stability: This is achieved by
dispersing the stored energy within two winding barrels, equalizing torque as well as reducing pressure
and friction on the bearings and pivots, resulting in improved long-term performance.
The RM 055 Bubba Watson is assembled using several sizes of spline screws in both the case and the
movement. These screws age well and provide better control of the torque applied during assembly,
and are therefore unaffected by the physical manipulations involved in assembly and disassembly.
The distinct construction of the RM 055’s case is designed to meet the demanding requirements of
sportsmen. Thus the ATZ bezel is made from tubes of aluminum oxide powder injected at a pressure
of nearly 2,000 bars. This high-pressure injection increases rigidity by 20 to 30% and reduces the
material’s porosity to an absolute minimum. ATZ is known for its high scratch-resistance (1,400 Vickers)
and its unchangeable color. Next to diamond, it is one of the hardest materials in the world. Long and
difficult machining using diamond tools is required to create a perfect example of this complex, curved
bezel and satin finish.
The case middle and back bezel are in grade 5 titanium with a protective white rubber casing. This
rubber is injected at high pressure around the titanium components, thus insulating the movement
from all vibrations. This special surface treatment also makes the watch very comfortable to wear.
A worthy successor to the RM 038 Bubba Watson, the RM 055 is a highly technical creation that is
innovative, sporting and hand-finished in the finest watchmaking traditions.

TECHNICAL SPECIFICATIONS FOR THE RICHARD MILLE RM 055
BUBBA WATSON

Available in rubberized grade-5 titanium caseband and back with ATZ front bezel.

CALIBER RMUL2 : 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 optimise 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: 28,000 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 r rubberized grade-5 titanium caseband and back

The ATZ bezel is based on aluminium 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 colour. After diamond, it is one of the hardest materials in the world. A long and difficult machining and moulding 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 elastomer 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

Theodore Diehl
Richard Mille Forum Moderator
'There is no excellent beauty that hath not some strangeness in the proportion.' - Francis Bacon