Black duct tape will fix that up like new,..
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I didn't like the rake angle on my mountain bike so I cut the down tube, and took a blow torch and sledge hammer to the top tube to rake it out, then screwed in an extension tube.
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I wanted to cut the head tube off and weld it back on at a better angle, but I suck at welding so I figured out a different way to do it.
My mountain bike is completely theft proof.