All of the predrilled holes are at 16" on center. See the spec sheet in the "Resources" section on the product page for the spacer hole distances. If the location of the spacer holes on the track doesn’t match the distance between the studs in your wall, then it is recommended that you first mount a header board to your studs and then mount the hardware kit to your header board. Mounting a header board is always recommended as it adds greater stability to your barn door installation. For bypass kits 1 x 8 board is sufficient for a header board.