Im going to be brazing on some canti-studs onto my roadie within the next few months. im wondering how far apart the studs need to be. Ive read that they should be between 75-85mm center to center. Im going to be running V-brakes. the reason im doing this is because I will be running a 27.5mm rim and some fatter tires. (Sun rhyno lite, im a big guy....)
The ones on my current project are 77mm. You should check on the specs for your brake, rim, and fork. You can do a tiny diagram showing where the studs need to be to allow the brake to work properly. Or try the rig out on another bike, if you have one available to see whethere they work, then copy that. With the V-brakes it may be adjustible enough, but cantis often just don't work when set up on a fork, if the arms aren't wide enough.