The BMC Fourstroke eplacement headset kit fit headtube size 1.5", 45°/ 45° ACB (OD52.0*ID28.6). It includes 2x FSA MR170 (070E-RS) bearings, an alloy H6153 crown race, and the alloy compression split ring.
Every headset part of the headset assembly is including in this kit for Integrated System Ø52 (IS52/28.6 | IS52/40).
2x MR170 {070E-RS