Hope Flat Mount Bracket Post Frame Or Fork To Flat Mount Caliper - Post Frame Or Fork To Flat Mount Caliper - R 140-160mmHope Disc Brake adaptors are CNC machined and ensure a perfect fit with all Hope Brake sets. CNC machined in Barnoldswick, England. Includes mounting bolts. To determine which type of mount you need just think about what size mounts your frame fork has and how much larger the rotor is that you'd like to run. Then choose the adaptor that will provide you with the amount of increase you need. Flat Mount Adaptors: X: Flat Mount F 140 (0mm increase) Y: