Bias Bar Reducer for OBPCB010 Our specially selected range of products that work in unison with all of our obp Motorsport core hardware. Whether you are looking for master cylinders, bias adjusters or replacement parts. obp Motorsport has you covered. Product Information: Designed for OBPCB010 Secured by a Locking Grub Screw Thread 1: 7/16” UNF Female Thread 2: 3/8” UNF Male.