Rebberg 13

History: The Rebberg watch movement was named as such because the location of Aegler's factory was on a street called - you guessed it - 'Rebberg'. This is a lever escapement movement with a cut bimetallic temperature compensation balance with Breguet overcoil balance spring and 15 jewel bearings. It is stem wound and set. Savonette movements were used in savonnette (hunter) pocket watches, and in Lépine (open face) wristwatches because they have the fourth wheel at 90 degrees from the stem. This allows the crown to be at three o'clock and the small seconds indication at six o'clock on the dial. Most of these movements were built with 15 jewels, but were occasionally made as a higher grade 17 jewel version.

This Aegler Rebberg movement carries the single name "Rolex" so this is a Rolex watch, not just a watch that was sold by the Rolex Watch Co. But notice that the Rolex brand name is engraved on the ratchet wheel. This is an easy component to change, just a single screw holds it in place. This was most likely an idea of Aegler's to reduce the amount of stock they needed to hold. They could cheaply hold ratchet wheels engraved with Rolex or any other name, and then when an order came in they could simply take unbranded movements and change the ratchet wheels to one with the name given on the order. This was a more cash efficient system than tying up lots of movements with names engraved on their bridges which then could only be sold to that customer.

The Rebberg movement had a good long run - 1902 to 1927, but it was eventually replaced by Aegler's new line - the Hunter.

Manufacturer: The Aegler watchmaking company was established in Biel / Bienne in 1878 by Jean Aegler. Biel / Bienne is on the language boundary between the French and German speaking parts of Switzerland, hence the dual name for the town. Biel is German, Bienne its French counterpart.

Hermann Aegler made ebauches (unfinished movements) of a small size. After Rolex was founded they started importing Aegler’s movements and used them to make a variety of “wristlets,” selling them principally in the UK and in the British Empire, above all in Australia and New Zealand. His belief in the wristwatch format was confirmed by a precision test at Kew Observatory in London on 15 July 1914, when a 25-mm Rolex “wristlet” attained a Class A certificate, previously won only by much larger pocket watches.

Until 2004, Aegler was a completely separate legal entity than Rolex - it was owned by the Aegler and Borer families. Starting in 1936, they only produced watches for Rolex and operated as if they were a subsidiary of the Rolex brand. Aegler even changed its legal name to be more "Rolex-like". Eventually, in 2004, Rolex completed the legal acquisition of Aegler and Aegler became a de jure as well as de facto division of Rolex. For this reason, movements made by Aegler from 1936 to 2004 considered "In-House" Rolex mechanisms as they were only available in Rolex products, despite the fact they were made by Aegler.