Die 5 1⁄4 ligne Bifora 55 is an early ladies’ form watch movement from Bifora.
It sill has got the classical design with partially angeled bridges, a scale on the balance cock and a stripes decoration.
The base plate is massive and has got the typical construction of small form movement where the gears and bearings partially overlap each other.
Of course, all bearings, except those of the minute wheel, contain rubies. In some models the minute wheel has got ruby bearings, too.
This movement has got really small third and fourth wheels, the third wheel has got a very long axle. That is not very watchmaker-friendly, but there’s no other way due to the limited space.
The large escapement wheel partially runs below the fourth wheel bearing, so, it’s the two-storey construction, which is typical for that kind of movements.
The screw balance is not shock protected and beats with 18000 A/h. The minute wheel is directly driven by the mainspring barrel.
On the dial side, there are no surprises, but you still find the yoke winding system, which Bifora pared down in later movements in favor of the cheaper rocket bar winding system.
In the lab
|Number of jewels:||15/17|
Nickel screw balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Size:||5 1/4 x 8 1/2''' (measured: 12,8 x 19,3mm)|
Flume: 1952 32|