Bifora 70

 
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Bifora 70

Description

1958 Bifora in Schwäbisch Gmünd, Germany, released their smallest round manual wind movement, the Bifora 70.

With a diameter of only 7 14 lignes (15,8mm) it was a perfect for the tiny ladies’ watches, which were very popular at that time. Nevertheless it is astonishing, why Bifora released a round movement of that size, since back then for those watches, tonneau-shaped movements were usually used. Maybe because of that, the production ceased already in 1962.

The Bifora 70 was also used by Dugena, where it got its caliber number Dugena 1204:

Dugena 1204 / Dugena 70

Dugena 1204 / Dugena 70

It’s unknown, if all Dugena versions are golden colored.

base plate

base plate

The Bifora 70 was built with 16 and 17 jewels. The specimen shown here advertises 17 jewels on the dial, but I can only find 16: 4x Balance wheel, 1x Ellipse, 2x lever bearing, 2x pallets, 2x bearing escapement wheel, 2x bearing fourth wheel, 2x bearing third wheel and one bearing jewel for the minute wheel on the movement bridge.

gear train

gear train

The gear train is tradionally constructed. It’s noteable, that the gears have a rather small diameter and a two storey construction is used, where the bearing of the fourth wheel is above the escapement wheel. Such a space-saving construction is normally only used on form movements, and on the Bifora 70, you see, that there’s a lot of unused space.

side view of the gear train

side view of the gear train

The screw-less anular balance in beared in two Incabloc shock protection bearings (on the dial side the flat version) and beats slowly with 18000 A/h. It regulares a pallet lever movement of swiss type. The beating frequency can be adjusted with a long regulator arm - a detail of a high quality movement.

Bifora 70: Dial side

Bifora 70: Dial side

The dial side of the Bifora 70 is nice to see, with its youke winding system, its flat Incabloc shock protection and the large cutouts for the escapement wheel and the lever pallets, which makes oling the pallets (or the surfades of the escapement wheel) easier.

In the lab

The specimen shown here came in working condition into the lab, so no service and oiling was made.

The second specimen (the Dugena one) had a broken balance wheel and also a broken minute wheel.

Timegrapher result

In the horizontal positions, the movement showed very good results on the timegrapher, but on the vertical positions, they are pretty peer.

horizontal positions
dial up +7 s/d 206° 2.8ms
dial down +9 s/d 197° 2.0ms
vertical positions
crown right (12 up) -2 s/d 163° 2.0ms
crown up (3 up) -90 s/d 177° 2.0ms
crown left (6 up) -150 s/d 161° 2.6ms
crown down (9 up) -50 s/d 144° 2.6ms

Technical data

Manufacturer:Bifora
Caliber:70
Number of jewels:16
Escapement:Pallet lever
Balance types: Nickel anular balance
Shock protection(s): Incabloc
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
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)
Functions:hour, minute
A/h:18000
Size:7 1/4''' (measured: 15,8mm)
Production period:1958 - 1962
Literature: Flume: K3 6
Inventory number:17035

Usage gallery

Bifora ladies' watch

Bifora ladies' watch

Dugena ladies' watch

Dugena ladies' watch

This movement, including the Bifora watch, is a kind donation of Götz Schweitzer to the movement archive. Thank you very much for the great support!