I've had a quick look for some info on your Rubis frame and it seems that it was a top quality tubing brand owned by Atelier de la Rive (who later made Vitus tubing). I found this quote:
Ateliers de la Rive, a company based on the outskirts of St Etienne, France, started making tubes in 1931. In the early post WW2 years their premium tubing was called Rubis, and widely used by French quality frame builders.
So everything seemed fine and then I found an article about French tubing manufacturers which had this to say:
In the 1930s there was a French brand of light weight tubing called Rubis. It's unclear whether it was affiliated with Ateliers de la Rive but it may have been a predecessor of Durifort and Vitus tubing .
So it's a case of two steps forward and one step back, however, at least both sources do agree that Rubis was a quality tubing (although they may not seem to know who made it)!!!
Ateliers de la Rive, a company based on the outskirts of St Etienne, France, started making tubes in 1931. In the early post WW2 years their premium tubing was called Rubis, and widely used by French quality frame builders.
So everything seemed fine and then I found an article about French tubing manufacturers which had this to say:
In the 1930s there was a French brand of light weight tubing called Rubis. It's unclear whether it was affiliated with Ateliers de la Rive but it may have been a predecessor of Durifort and Vitus tubing .
So it's a case of two steps forward and one step back, however, at least both sources do agree that Rubis was a quality tubing (although they may not seem to know who made it)!!!