Zenith Chronomaster Sport Skeleton: El Primero 3600 SK Exposed in Four New Variants
Zenith Exposes the High-Beat Heart of the El Primero with New Chronomaster Sport Skeleton Collection
Zenith has expanded its popular Chronomaster Sport line with four new skeletonized variants, stripping away the dial to reveal the inner workings of the El Primero 3600 SK movement. Debuted at Watches & Wonders 2026, these chronographs showcase the brand's 1/10th-of-a-second precision through a transparent sapphire crystal dial.
From Nostalgia to Modern Sport
When the Chronomaster Sport launched in 2021, it marked a turning point for the El Primero – a shift from vintage nostalgia to contemporary sports watch territory. The new skeleton versions continue this evolution, leveraging the Calibre 3600's 5Hz frequency to deliver hyper-precise timing with the central chronograph hand completing a full rotation every 10 seconds.
The skeletonized movement, previously featured on the Defy Skyline Chronograph Skeleton, has been adapted with differently shaped bridges for the Chronomaster Sport. Key components are visible from both dial and caseback, including the blue column wheel, horizontal clutch architecture, silicon escape wheel, and star-shaped openworked rotor.
Four Distinct Variants
| Model | Case Material | Bezel | Counters | Price |
|---|---|---|---|---|
| Steel, Black | Stainless steel | Black ceramic | Grey, anthracite, blue tri-color | EUR 16,500 |
| Steel, Green | Stainless steel | Green ceramic | Grey-toned | EUR 16,500 |
| Rose Gold | 18k rose gold | Black ceramic | Trio-tone | EUR 31,200 |
| Rose Gold Diamond | 18k rose gold | Diamond-set | Diamond indices | EUR 111,400 |
Technical Excellence on Display
All four versions share 41mm cases with classic pump-style pushers, screw-down crowns, and 100m water resistance. The ceramic bezels are engraved with a graduated 1/10th-of-a-second scale, while the tinted sapphire dial creates a smoked-black periphery that transitions to a transparent center.
New ZenClasp System
The steel models debut Zenith's new patented ZenClasp folding clasp, developed over three years (approximately 1,800 hours). This tool-free micro-adjustment system offers up to 10mm of adjustment in 2.5mm increments across 5 positions. Each clasp has been validated through over 600,000 opening and closing cycles – equivalent to more than 10 years of real-world use.
El Primero 3600 SK: Under the Hood
The skeletonized El Primero 3600 SK maintains all the technical prowess of its solid-dial sibling: 35 jewels, 319 parts, 36,000 vph (5Hz) frequency, and a generous 60-hour power reserve. The silicon escape wheel and lever ensure long-term reliability, while the integrated column-wheel chronograph with horizontal clutch represents the pinnacle of chronograph construction.
FAQ
Q: Does skeletonization affect legibility?
A: The sapphire dial with smoked-black periphery creates a layered effect. While the applied indices and hands feature Super-LumiNova, some may find reading the time requires more attention than the solid-dial versions.
Q: What is the 1/10th-of-a-second function?
A: The central chronograph hand completes a full rotation every 10 seconds (6x faster than standard chronographs), allowing direct 1/10th-of-a-second readings against the bezel scale.
Q: Is the diamond-set version a limited edition?
A: Yes, the 18k rose gold model with diamond-set bezel and baguette-cut diamond indices is limited to just 10 pieces worldwide.
Source: Monochrome Watches | aBlogtoWatch
Discover the full Chronomaster Sport range in our Zenith collection.