Angular Contact ABEC-5 Grade
Angular Contact cartridge bearings specifically designed for hubs and bottom brackets. In standard radial bearings, only 3 or 4 balls make contact during the load, at any given time. In Angular Contact bearings, ALL balls are engaged and spread the force over a larger surface area, to decrease friction and minimize wear.
Grade 5 chromium steel balls are within 5/1,000,000″ round. These are military level specification, used for precision equipment. R-64 hardness, of the highest grade. 52100 high carbon chromium alloy races go through a vacuum de-gassing process resulting in the purest chromium alloy steel, hardened to R-62. Nylon with graphite retainers are virtually friction-less while providing constant lubrication.