to get cp10 to fit scribe a line 25 mm from the bottom (hole center) then do the same on the back face of the 2 vertical tubes of the seat back trim the top end to suit with the two scribed lines in line
i made them 4mm shorter all removed from the top end of cp10 to get the hole center 25mm above the base tube as shownin the diagram
hope that clears it up
