Rolf prima ares4 disc rear road wheelall the power and aerodynamic advantages of the ares4 but designed for disc brakes the ares4 disc combines rolf primas weight savings and wind cutting paired spoke technology with their supremely aerodynamic delta rim profile perfected in the wind tunnel and validated with real world results featuresrim material carbon clincherfreehub material cnc machined titaniumwheel size 700cspoke count 20spoke type bladed cx rayrim depth 42mmbrake track width