Magura QM51 Flat Mount Disc Brake Adapter For Flat Mounts If you need to adapt a post mount to work with a bigger rotor, you'll need an adapter. The Magura QM51 Flat Mount Disc Brake Adapter is designed to mate Magura disc brakes with a variety of frame mounts and rotor sizes. The QM451 adapter adapts rear wheel flat mounts to work with 160mm rotors. It includes the hardware necessary to mount the adapter to the frame. Features Adapts a Magura 160mm rotor to a rear wheel flat mount Includes the hardware to mount the adapter to the frame Manufacturer's part number: 2-701-600 | Magura | Qm51 Flat Mount Disc Brake Adapter M5X10 T25