We have added a feature to our writing about cantilever brakes which we call the "Bike-Pro profile measurement" This is the distance expressed in millimeters from the center of the mounting stud to the end of the arm. The measurement is made as though the each arm were installed. The left and right arm measurements are added together to come up with a "Bike-Pro profile measurement". What's the least expensive way to guarantee good cantilever performance? Two words, buy V-brakes!