The Audemars Piguet Royal Oak Selfwinding Chronograph reference 26240ST.OO.1320ST.03 is a 41mm luxury sports watch released to commemorate the 50th anniversary of the Royal Oak collection. This timepiece features an octagonal stainless steel case with a thickness of 12.4mm, characterized by its signature brushed and polished finishes. The silver-toned dial, often referred to as white, displays the Grande Tapisserie pattern and is equipped with white gold applied hour markers and Royal Oak hands with luminescent coating. It is paired with an integrated stainless steel bracelet featuring an AP folding clasp and includes a transparent sapphire crystal caseback that reveals the commemorative 50th-anniversary oscillating weight.
At the heart of this model is the in-house Calibre 4401, a self-winding movement composed of 381 parts with a frequency of 4 Hz and a power reserve of approximately 70 hours. The watch features a flyback chronograph complication, which allows the wearer to restart the chronograph without having to stop and reset it first. Additional functions include hours, minutes, small seconds at the 6 o’clock position, and a date display located between 4 and 5 o’clock. The movement utilizes a column wheel and vertical clutch system to ensure a smooth engagement of the chronograph function. It is water-resistant up to 50 meters, making it suitable for light splashes but not high-impact water activities.
General reviews of the 26240ST highlight its exceptional external finishing and the aesthetic appeal of the Grande Tapisserie dial, which provides high legibility and a classic look. Owners frequently praise the watch for its versatility, noting it can be worn in both casual and formal settings. However, some collectors mention that the stainless steel surfaces are prone to scratches, and the 41mm case can wear larger than its stated dimensions on the wrist. While the Calibre 4401 is appreciated for its technical improvements over previous generations, some users have reported minor reliability issues, such as the chronograph minute hand drifting or the movement requiring earlier-than-expected servicing.