The Shimano BB-RS500 bottom bracket is recommended for 24 mm Hollowtech II cranks from the Tiagra, Sora series and for numerous similar models. Depending on the version, it fits in a road frame with BSA bottom bracket thread and 68 mm housing width or in a frame with ITA bottom bracket and 70 mm housing width. BB-RS500 impresses with its durability and improved seal construction.