Serving NYC/LI since 1978
Swapping Necks - Customs by Ripper
Here is the proper way to rake, stretch or repair frame damage. Step one is to cut the tubes flush. A pipe cutter would be a great way to make the initial cut, but do not cut all the way through with a pipe cutter as it adds a lip to the inner wall of the tubing. Instead, make the cut about 1/2 way through the tubing, then finish off the cut, carefully following the line made by the pipe cutter, with a cut-off wheel. Finish this with a grinding stone inside the tubing to remove the burr left by the cut-off wheel. Next, make a "V" groove on the top edge of the tubing. This is to allow better weld penetration (please note, in the haste to get these pictures taken, the edge was not "veed" on this neck until after the pictures were taken. Normally, the last 1/8" to 1/4" or so of the tubing would be angled down from the outer to the inner edge. This can be done by hand or on a bench grinder if the part is manueverable). A 3/8" hole is then drilled on each side of the weld, following the rule of thumb below to determine placement of the hole, which will be an access point to weld in the inner sleeve added in the next step.
A second tube whose outer diameter is the same as the inner diameter of the frame tubing (actually, slightly less to allow it to slide in easier) is added as a sleeve inside the frame tubing. The general rule of thumb for the length of this inner sleeve is 1.5 times the diameter of the tube being sleeved on each side of the weld. For example, if you are working with 1" tubing, your sleeve length would extend 1.5" into each side of the weld, making the overall length of the sleeve 3".
The inner sleeve is fully welded to the outer tubing through this hole. The weld is a "plug weld", which should completely fill the drilled hole, making the inner and outer tubing essentially one piece in that area. Then the two frame halves are joined and the procedure is repeated on the other side of the joint. Once both sides are aligned properly and all plug welded together, then the welding is completed by fully welding the joint itself. Please note that you will have to pre-plan this and sometimes you need to slide the sleeves into place temporarily while making the rest of the frame slide together, before welding them into the outer tubing.
PLEASE NOTE - Do NOT use a solid plug instead of a smaller tube. This will make the frame too rigid in one area and can cause problems in the event of an accident.
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