The Hangzhou 7500 series is a fully skeletonized automatic calibre produced by Hangzhou Watch Movement, a Chinese movement manufacturer. Operating at 28,800 bph in a 30mm diameter, 5.23mm thick architecture with 21 jewels and approximately 80 hours power reserve, it is a time-only three-hander with no date complication — the entire movement architecture is open, exposing the gear train, mainspring, and balance wheel through the skeletonized bridges and mainplate. The variant used in replica production is commonly referenced as the 7530, a member of the Hangzhou 7500 series sharing the same core architecture and specifications.
The 80-hour power reserve is the defining practical characteristic of this calibre — significantly longer than the 36 to 45-hour reserves typical of Mingzhu and Sea-Gull calibres used in comparable replica references. This extended reserve is achieved through an extra-long mainspring housed in a single barrel that occupies a significant portion of the 30mm movement frame — the barrel is visibly prominent in the skeleton layout alongside the balance wheel. The variant used in replica production is commonly referenced as the 7530, part of Hangzhou's 7 series family which includes variants such as the 7530A, 7520A, 7540A, and others sharing the same core architecture. The movement may also appear listed as HZ7500 or PTS 7500 — PTS Resources is a distributor for Hangzhou and sells this calibre under their own designation.
In Practice
- The Hangzhou 7500 series operates at 28,800 bph — a higher beat rate than the 21,600 bph calibres common in mid-tier replica production. The higher frequency produces a smoother sweeping seconds hand motion that is particularly noticeable in skeleton references where the movement is fully visible through the dial.
- The 80-hour power reserve is the standout specification of this calibre. A fully wound Hangzhou 7500 series movement will run for approximately 80 hours without wrist movement — meaning the watch will continue running through a full weekend of non-wear without requiring winding before resuming accurate timekeeping.
- The fully skeletonized architecture is a factory design feature — not a modification applied by replica manufacturers. The bridges, mainplate, and rotor are shaped to expose the complete mechanical assembly, including the visible mainspring at 12 o'clock that tightens visibly as the watch is wound.
- Hacking (stop-seconds) and hand winding are both present. The movement uses a bidirectional Magic Lever style pawl winding system and a Novodiac style anti-shock device — both established mechanical features found in quality automatic calibres across the broader watch market.
- The balance wheel at 6 o'clock visually echoes a tourbillon aperture — this is an intentional design choice by Hangzhou. The rotating mechanical element is genuine and visible during normal operation; the tourbillon gravity-compensation function is not present. The movement is a time-only skeleton automatic, not a tourbillon.
Related Terms
Miyota Movement · Sea-Gull ST2500 V2 · Skeleton Miyota 9015 Clone · Miyota 8N24 V3 · Super Clone
Read Next
For a full overview of movements used in replica watches — including how the Hangzhou 7500 series compares to other skeleton calibres — read: Replica Watch Movements Explained