Geneva Sport 51

 
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Geneva Sport 51

Description

To get a proper caliber number for a Geneva Sport movement is very difficult, since the online and offline literature for this mystic manufacturer differ.

The 11 1/2 ligne movement shown here is most likely a Geneva Sport 51, even though it is marked as “GSW 40,41”. Since the base plate look the same for both caliber families and the movements only differ in the bridges, it is quite possible, that they just used the same base plate for them.

Geneva Sport 51: base plate

base plate

All important bearings contain rubies, the minute wheel lacks a ruby on the dial side, but has got one on its bearing cock in the movement side.

Geneva Sport 51: base plate with minute wheel

base plate with minute wheel

With the centrally beared (under its own cock) minute wheel, this movement represents more or less state of the art of the 1960ies.

The Geneva Sport 51 has got a directly driven center second hand.

In the 21 jewel version shown here, the bearings for the third wheel, seconds wheel and escape wheel are covered with cap jewels, as well, as the dial side bearing of the escape wheel. With them, the high number of 21 jewels was achieved.

Geneva Sport 51: gear train

gear train

The two leg screw balance is not yet shock protected. It still beats slowly with 18000 A/h, which can be adjusted on the hairspring key only.

As escapement, a classical swiss pallet lever escapement was used.

Geneva Sport 51: side view of the gear train

side view of the gear train

On the dial side, the balance wheel bearing is covered with a simple cap jewel (inserted in a long plate, like the cap jewel for the escape wheel). You can also see the preparations for a cap jewel for the third wheel.

Geneva Sport 51: Geneva Sport 51: Zifferblattseite

Geneva Sport 51: Zifferblattseite

This copper toned movement has got a yoke winding system.

Technical data

Manufacturer:Geneva Sport
Caliber:51
Size:11 1/2''' (measured: 25,6mm)
A/h:18000
Number of jewels:21
Escapement:Pallet lever
Balance types: Nickel screw balance
Shock protection(s): none
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Hairspring key
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel
  • center minute wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:3 hole(s)
Features:
  • SCD (direct center seconds)
References: Flume: K2 -
Inventory number:20011