Tron et Berthet designated saddles with the alloy frame with a capital letter I. So the example under discussion would be a 90I. The 90I was also offered with the Rebour treatment, rodee main. Such products are identified as model 90IR.

ZEUS manufactured clamp parts to fit an I framed saddle to the ZEUS Gran Sport/Criterium and Campag Record/Super Record pillars. They also fit the "copyoglo" pillars such as made by Anpi and Sakae Ringyo.


The alloy frame has zero give. The steel rail frames actually do have a slight amount of give with the weight of the rider upon them.