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You are here: Home / Movements / SW501 M BV c

SW501 M BV c

Last Update: June 5, 2019

Brand:Sellita
Family:
Sellita SW500 Family
Height:7.00 mm
Jewels:21
Reserve:58 hours
Frequency:28,800 A/h
Winding:Hand winding
Diameter:30.00 mm (13.25 ligne)
  Complications:2-Button, Cam Switching Chronograph, Chronograph, Hacking Seconds
Hands:12 Hour Chronograph Hand at 6:00, 15 Minute Chronograph Hand at 12:00, Central 60 Second Chronograph Hand, Central Hour Hand, Central Minute Hand
Distinguishing Technical Characteristics
Hand-Winding
Clockwise Balance Cock
Screw Regulator
Balance at 1:30
Production: 2018 – Current
1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s

Sellita Cal. SW501 M BV c is a hand-winding chronograph movement with no running seconds in the Sellita SW500 family. It is based on the ETA 7750 design and shares many components with that movement. Sellita introduced the “Bicompax Vertical” design in 2018 along with the hand-winding version of the SW500 line. All hand-winding SW500 M movements feature a special bridge with larger jewels and a cut-out to allow the cam-switching chronograph function to be visible through a display caseback.

This movement omits the small seconds subdial at 9:00, making the movement resemble a classic Venus 170 or Valjoux 76 but without any running seconds indication. It features a 12 hour chronograph counter at 6:00 and a 15 minute chronograph counter at 12:00. There is no date function.

Sellita SW500 and SW600 Technical Information

The Sellita SW500 and SW600 movements are based on the Valjoux 7750 design, itself based on the Valjoux 7733 and Venus 188. This movement is known for durability and flexibility and is used as a base in many watches, from entry-level chronographs to the famous IWC “Il Destriero Scafusia” grande complication. It is a large and relatively thick movement, measuring 13.25 ligne (30.00 mm) in diameter and 7.90 mm thick.

Although based on a classic design, the modern SW500 and SW600 is robust and full-featured. It operates at 4 Hz (28,800 A/h) with an efficient uni-directional central winding rotor. The day and date wheels feature crown-operated quick correction and a stop seconds (“hacking”) feature is included. The base movement has the famous Valjoux 6-9-12 subdial layout with small seconds at 9:00, but many Sellita versions have other subdial designs.

One major differentiator for the Sellita movements is the use of an eccentric screw for regulation rather than the traditional Valjoux articulated index.

ETA/Valjoux uses a two-piece index regulator with a movable pointer on the 7750
Sellita uses an eccentric screw regulator on all of its movements, including the SW500

Sellita SW500 M BV Variants

Day and DateDate OnlyNo Date
30 Minute CounterSW500 M BV aSW500 M BV bSW500 M BV c
15 Minute CounterSW501 M BV aSW501 M BV bSW501 M BV c
Images are taken from official publications and are used here for commentary and educational purposes. Copyright is held by the original owner as noted.

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