HI Jan,
Durifort Was made by Ateliers De la Rive and was the predecessor to Vitus
172 which was a seamed double butted cromo steel, Durifort was a seamed
double butted hi carbon steel, it was pretty heavy 1.1 x.9 if I recall
correctly. I built about 10 frames with it when I first started building
back in the early 70's. I still have a couple of Durifort decals. I got the
sets from Vic Frasie of Paris Sport Cycles of N.J.
God Bless
Anthony Mezzatesta
Mezzatesta Custom Cycles
914 Berkley Manor Dr.
Cranberry Twp. PA 16066
724-778-8224
Cell: 917-214-9229