ENDURO ACB 45X45 150 BO 40 X 52 X 7MM 45 X 45DEG Specialized Lower Headset Bearing Color:Chromium Steel Black Oxide Alternatively you can use the Color:Skinwall Alternatively you can use the thin washers to mount a bracket on one side and use the spare bracket on your second bike Note: this will only work with certain frames with enough clearance ACB 4545 150 BO 1 1 2 Black Oxide Angular Contact Headset Bearing (34mm x 52mm x 7mm: 45x45 deg) Angular contact headset bearing featuring anti corrosion Black Oxide Magnetite coated 52100 High Carbon Chromium alloy races paired with grade 10 Balls XD15 aerospace stainless (races and balls)