2011 Polaris 550 Sportsman Rear Brake Rotors Disc & Severe Duty Brake Pads Race-Driven Rear Standard Brake Rotors and Severe Duty Sintered Metal Brake Pads. Race-Driven exclusive sintered metal compound brake pads are designed to withstand extreme conditions Standard rotors are designed to replace original stock rotors 2011 Polaris Sportsman 550