That's correct. The top tube and down tubes are commercially pure titanium, which is bonded into aluminium (and I think steel) lugs, with a steel rear triangle. The more 'up market' Ti frames instead use welded, aerospace-grade titanium.
These old M Trax and Dynatech frames were an interesting idea - giving some of the benefits of Ti (flex) , while keeping a stiffer rear triangle, without breaking the bank.
As I understand it its the top and head to bb tubes that are titanium. The rear triangle including the seat tube are ChroMo. Still a great ride though, I've got 2 of them.
