When the lag eye bolt 234 is loosened or removed from the threaded aperture 233, the tubular frame 232 can be slid up and down the frame leg 210 to a desired position, and then secured at that position by tightening the lag eye bolt 234 through the aligned threaded apertures 233 and 212.FIG. 3C is a perspective view of an assembled header bar 205 for frame end in accordance with embodiments of the