Rolex Bubble Back Watches.



The Rolex Bubble Back or Bubbleback was first manufactured in 1933.  These watches got their name due to the fact that the auto wind mechanism appeared to simply be bolted onto the basic Rolex movement.  This attachment was rather large so it was necessary to round out the case back in order to accommodate the mechanism in order to allow proper functioning of the oscillating weight which made complete 360 degree rotations within the case.

The Rolex Bubble Backs were produced possibly as late as the early 1960's.  Many good examples exist to this day possibly due to the simple and durable basic 18 jewel design of the movement.

Most of these watches were time only and also had a sweep second hand.  Later models included a date mechanism and were possibly the first DateJust models produced by Rolex such as the model 6075 which was manufactured in 1948.  Some of these early Bubble Backs also had subsidiary seconds bits and many also had the popular California dials which had both Roman numerals and Arabic numerals.

None of the Bubble Back cases had bezels that could be removed.  Rather than the watch crystal being held in by compression using a bezel crystals were installed by the constriction method.  The most common crystal used for these watches is the Tropic 30 crystal.  It measures 2.6mm in height.  The inside diameter is 24.6mm and the outside diameter is 25.5mm.  The Bubble Back shown below has a Registered Design of 6015.  Case sizes for the gents watch is 31mm, the ladies is 24mm.  Lug sizes for the gents watch is 16mm and the ladies is 13mm.

     These watches had two serial numbers.  One was located on the movement and the oscillating weight had a cut-out so that the number could be seen.  The auto wind mechanism also has a serial number that is usually proceeded by a letter such as the "N" for the watch above.  The serial number of this watch is 39590 and the number on the auto wind mechanism is N 90098.


On the dial side of the movement you will see the Rolex stamping along with the "N" marking which denotes the movement size.  The auto wind mechanism did not contain any jewels.  The movement itself has 18 jewels.  You will notice the stacked gears above the mainspring barrel.  This fits into the large opening of the auto wind mechanism.  This is why these movement are so thick and why the case became known as a Bubble Back.

        The first picture shows the case back with the Rolex markings and design number.  The second picture shows the original plastic crystal.  The third picture shows the dial with the raised gold numbers.

      These two pictures show the movement with the auto wind mechanism installed.

The restored watch appears in the first two photos above at the beginning of this article.