MAFAC Tandem Canti, Spring problems
 

So I'm building up my Kogswell and when i installed the mafac canti's the spring on the tightest setting has no tension to keep the brake off the rim, on the lightest setting it pushes the brake into the rim, what am I missing?

In my vague memory of Mafac cantis, try the following: I am pretty sure that the springs are specific per left and right side. See if you can carefully bend the entire spring assembly further apart. I have done this on Dia-Compe cantilever springs to increase the tension on the spring, even when the spring was set at its highest tension level. Also check that the entire cantilever brake is cleanly moving on the braze-on stud-i.e. that it is not binding as it moves, even with no spring pressure. I think that bending the springs more open will increase the tension enought to solve the problem. Hope any of this may help you.