Cane Creek Headset Service Parts. Features: Crown races, compression rings and bearings for servicing Cane Creek headsets (see Aheadset for other parts) * Upper and lower replacement bearings sold as a set for tapered fork headset applications ** AER series bearings are cross-compatible across the line, using aluminum and steel construction, 35% lighter than 110 and 40 series bearings 40-series crown races are cross compatible with all series headsets Specs: Fits Model: crown race (52/40) steel Size: 1.5" (+3mm) Package: each Remarks: Allows for extra clearance between downtube and fork