Internal parts are cross-compatible across 1, 4 and 11 seriesConsistent stack heights across 1, 4 and 11 SeriesBottom assemblies include bottom cup, sealed oxide bearing, and crown race
Cane Creek's 40 IS52/40 Bottom headset cup fits 52mm lower head tubes and forks with a 30mm crown race. It's constructed from aluminum with a steel crown and low-friction seals to keep muck out and bars spinning smooth.
Brand: Cane Creek, Model: 150075, Color: Black, Size: One Size