The Answer BMX Integrated headset reducer allows you to run a 1″ front end on a 1-1/8″ head tube frame. The headset installs like a typical integrated headset with an OD of 1-1/8″ and ID of 1″. This is an attractive option for those wanting to move a young rider to a larger frame without adding the weight of the 1-1/8″ front end just yet.