The Raleigh Sports that I know of use stamped steel brake calipers with a center bolt whose adjustment is not the same as many common side pull calipers. It is easy to, after time, neglect or poor adjustment attempts to end up with too tight a caliper pivot/center bolt. Just like the front wheel bearing adjustment where the securing nut is also the adjustment lock nut the caliper arm friction is set with the securing (the nut behind the crown for the front brake) AFTER the center bolt is rotated to a point where after the securing nut's tightening allows the caliper arms to still more freely and without slop or play. This adjustment is simple once understood. Andy