The Proteus Framebuilding Book - Proteus Bicycles

the frame members apart. The difficulty of taking a frame apartshould not be underestimated. While building a frame the stressof fitting parts together is done before the actual heating of themetal. In frame repairing the stress is usually applied to themetal while it is at its highest temperature. Also complicatingthe problem is the possibility the frame was built poorly in thefirst place. This causes problems when the frame components werefitted together too tightly. Sometimes they may have been hammeredtogether. Even worse they may have been pinned together. Allthese conditions are going to create problems for you. When themetal is heated to make the braze material molten enough to allowthe joint to be pulled apart, the metal is prone to distortion and.fracture. This should be kept in m.ind while doing any frame repair.Any time a frame repair requires pulling something apart that isattached in more than one place, the part must be cut to allow eachjoint to be heated separately. Trying to simultaneously heat andpull apart two joints will give you nothing but trouble. For example,a dropout has this problem. It is attached to both the seatstay and chainstay. The first step in replacing a damaged dropoutis to cut it in half so that one half is connected to the seat stayand the other portion to the chainstay. VJhen cut the dropout usuallyreleases some tension in the frame so that the two parts of the dropoutno longer line up. This allows some room for pulling each partof the dropout from the respective stay. This room is necessary becauseyou want to pull the dropout straight out of the stay, not atan angle. Pulling the dropout at an angle will break off the end ofthe stay. If the dropout is tight it should be wiggled around everso slightly to help loosen it. If it still doesn't come out try96