This site uses cookies for monitoring purposes. If you continue using this site, you accept this cookie policy.

Bifora 70

 

Bifora 70Bifora 70

Description

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

With a diameter of only 7 1/4 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 70Dugena 1204 / Dugena 70

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

base platebase 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 traingear 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 trainside 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 sideBifora 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.

 

 

 

 Technical data

ManufacturerBifora
Caliber70
Number of jewels16
EscapementAnchor with pallets
BalanceNickel
Shock protection(s)Incabloc
Balance cock directionclockwise
Hairspring studfixed
Regulator typeLong regulator arm
Movement constructionFork
Escapement wheel, Fourth wheel, Third wheel, Center wheel
Mainspring barrel
Construction typesolid construction
Winding mechanismyoke
Setting lever spring3 holes
FunctionsHour, minute
Beats per hour18000
Size71/4''' (measured: 15,8 mm)
Production time1958 - 1962
Image in Flume Werksucher K3 6
Inventory ID 17035
Bifora 70BiforaBifora701958 - 19627 1/4'''Bifora 7016 Jewels, 7 1/4''', 18000 A/h
Factsheet

 

 

 

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

vertical positions
positiondeviationbeat error amplitude
12 up  -2 seconds/day  2.0 ms  163 °
3 up  -90 seconds/day  2.0 ms  177 °
6 up  -150 seconds/day  2.6 ms  161 °
9 up  -50 seconds/day  2.6 ms  144 °
horizontal positions
positiondeviationbeat error amplitude
dial down  +9 seconds/day  2.0 ms  197 °
dial oben  +7 seconds/day  2.8 ms  206 °
timegrapher measurings

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

Either this movement is in urgent need of a service, or the balance wheel is harmed. In any case, the rates of the vertical positions are not representative for this caliber, they are only a snapshot of the measured specimen. 

 

 

 

Usage gallery

Bifora ladies' watchBifora ladies' watchDugena ladies' watchDugena 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!