Originally Posted by
lunacycles
I don't know what brand brakes you have, but usually with cantilevers, there is a spring adjustment screw on each arm that controls the spring. It is usually just behind/below the body of the brake arm, a little phillips head bolt (or 2mm or 3mm allen bolt). If you want to move a pad away from the rim (and you are sure the wheel is seated propertly), tighten that screw on said brake arm, or, conversely, loosen the screw on the opposite one. this is a super easy adjustment and just a damn shame if you have to pay a bike shop to do it.