stantion/crown, steerer/crown interface I suspect. You can normally make them creak/click by holding the front wheel between your knees & trying to rotate the bars. Difficult to do much with it – may be warrenty, my 32 vanillas do it, I can stop it for about 6 months at a time by putting the bike upside down, applying thin chain lube to the stantion/crown interface, applying heat with a hot air gun to the crown & vigerously pushing/pulling the lower legs with the wheel removed, reapplying lube & heat until the creaking stops.