Lynn,

Nice... +1

Durifort with butted main tubes from the 1960's to the mid 1970's had the same wall thickness tubing as the Reynolds 531 "Sport" tube sets used on a large number of production frames back then: 1.0mm x 0.7mm thick butted main tubes, the stays were about the same too, but the fork blade were 0.2mm thicker.

Reynolds 531 was about 35% stronger than Durifort in the "pre-brazed" condition. Durifort was much less sensitive to heat so the after brazing strength was only 20-25% less than 531. (Vitus 172 was closer to 531 in strength.)

Durifort tubing was seamed but the main tubes were cold worked to size which eliminated any shortcomings..


Here's an older spec sheet showing slightly thicker main tubes. Note: Rubis 888 and Durifort 888 were the same thing. The main tubes were 0.8mm straight gage. I think that it may have been a rounding error:

The tubes were embossed with DURIFORT but sometimes it wasn't deep enough to see.




from the late 60's until the early 70's Durifort came with these water slide decals. They were pretty fragile so many times they didn't survive normal use. The next ones used this design but on a foil film self adhesive base.




About 1973-74 they switched to this design, first on Mylar foil then using thin self adhesive film.



The mid 70's version.


I put more miles on my Bertin C34 with a Durifort frame than any other bike that I've owned.

I used Durifort tubing on the first frames that I built in 1976 because it was very forgiving with regards to over heating plus it was cheap ~$11 a set.

verktyg