Campagnolo Athena Rim Brake Caliper - Rear - Silver - BR10-ATRCampagnolo Athena Rim Brake Caliper Rear Silver BR10 ATR Campagnolo's objective is to provide both professional and amateur cyclists with the best braking system possible, adapted to their riding style. There are those who prefer to always have the maximum power available (dual pivot on the front and rear), and those, on the other hand, who prefer more controlled and modulated braking, with the mono pivot in place of the dual on the rear brake.