Description
Richard Mille has unveiled the RM 55-01, the long-awaited successor to the discontinued RM 055 "Bubba Watson" line — and unusually for the brand, it is the simpler, lighter, more focused proposition. Where the RM 055 leaned on its golfer-friendly story and its tonneau silhouette, the RM 55-01 is a pure exercise in mechanical lightness, built around a brand-new in-house manual-wind calibre — the RMUL4 — packaged inside three signature Richard Mille case finishes: White Quartz TPT, Grey Quartz TPT, and Carbon TPT.
The RMUL4 is the headline. It is a clean three-hand movement (hours, minutes, central seconds) that weighs under five grams, with a free-sprung 4 Hz balance, twin series-coupled mainspring barrels and 55 hours of power reserve. Richard Mille's stated aim with this calibre is "extreme lightness" — and at this weight, with this finishing, in this case, it is hard to point to a direct rival.
Design
The case keeps the RM tonneau silhouette but moves to a more wearable proportion than the original RM 055 — 38 mm × 49.94 mm with a 12.3 mm thickness. The three-piece architecture is sealed by 12 grade-5 titanium spline screws, and each variant uses a different Richard Mille composite for the case body: White Quartz TPT (a deep-white crystalline weave), Grey Quartz TPT (a charcoal-grey woven texture) and Carbon TPT (the brand's familiar dark carbon fibre composite). The dial is fully skeletonised, exposing the RMUL4's grade-5 titanium baseplate and bridges, with the textile-like weave of the case carried inwards behind the movement. The hands are skeletonised arrow-shape with luminous inserts. The strap is rubber, colour-matched to each case execution, fastened to a titanium folding clasp.
Specifications
- Reference: RM 55-01 — three executions: White Quartz TPT, Grey Quartz TPT, Carbon TPT
- Case: 38 mm × 49.94 mm × 12.3 mm, three-piece tonneau, sealed with 12 grade-5 titanium spline screws
- Crystal: Sapphire with anti-reflective treatment (front and back)
- Dial: Skeletonised; case-matching textile weave back panel
- Movement: Calibre RMUL4 — in-house, hand-wound, grade-5 titanium baseplate and bridges
- Calibre mass: Under 5 grams
- Frequency: 28,800 vph (4 Hz) — free-sprung balance
- Power reserve: 55 hours via twin series-coupled mainspring barrels
- Functions: Hours, minutes, central seconds
- Water resistance: 50 m
- Strap: Rubber, colour-matched; titanium folding clasp
- Limited edition: Continuous (per execution)
- Price: Approx. US$212,000
What's Exciting
The RM 55-01 is the first time Richard Mille has put out a successor to the Bubba Watson line that is genuinely simpler, not more complicated, than its predecessor. The RMUL4 is structurally a descendant of the RMUL2 inside the original RM 055, but it has been reworked with new finishing, a refined free-sprung 4 Hz balance and an updated bridge layout for visual clarity through the skeletonised dial. The fact that the calibre weighs under five grams, in a watch that itself stays well under 30 grams in some executions, is the headline; for collectors who have wanted "a clean, time-only RM with the modern movement," this is the answer. The grey quartz TPT is the standout aesthetic — a softer, more wearable colour-way than the brand's usual loud palette.
History
The RM 055 — the "Bubba Watson" — debuted in 2010 as Richard Mille's lightweight time-only signature, named for the brand's long association with American golfer Bubba Watson, who famously wore the watch through Masters-winning swings. Across four generations between 2010 and 2022 the RM 055 explored white ceramic, ATZ, sand-blasted titanium and ALUSIC cases. The line was quietly retired in 2023, leaving the brand without a true sub-tourbillon time-only manual-wind in current production. The RM 55-01 explicitly fills that gap, but with a movement re-engineered around hyper-lightness rather than the original RM 055's "lightweight golfer's tool" narrative — a shift away from athlete sponsorship and toward pure technical statement, in line with where Richard Mille has been heading since the launch of the RM UP-01 ultrathin in 2022.
