Fi'zi:k Arione R3 K:ium Saddle. The Fi'zi:k Arione saddle is frequently seen on the bikes of professional cyclists and with good reason. It's made for riders who have superb spinal flexibility what Fi'zi:k considers a Snake in their Spine Concept fit system and the saddle's long, flat, narrow profile caters to that physical capacity. The Arione R3's Wing Flex shell flexes downward where the inner thigh contacts the saddle, allowing more efficient pedaling and full range of motion. Additionally, the K:ium alloy rails are lighter than titanium to shave grams without compromising strength.