Angular contact bearings change how load gets distributed across the bearing assembly. In standard radial bearings, only three or four balls carry the load at any given moment as the bearing rotates. Angular contact bearings orient the races so all balls engage simultaneously, spreading force across the entire bearing surface rather than concentrating it on a few contact points. The Wheels Manufacturing BSA Threaded Angular Contact Bottom Bracket uses Enduro angular contact bearings built to this specification, delivering smoother rotation under load and extending service life compared to conventional bottom bracket bearings.

The external cup design threads into standard BSA English-threaded frames with 68mm shell widths, making this a direct replacement for Shimano Hollowtech II bottom brackets. Same threading, same tool interface, same installation process, but with bearing internals designed specifically for the rotational loads bottom brackets face. The bearing races sit at an angle that handles both radial forces from pedaling and axial forces from side-to-side movement, which radial-only bearings manage less efficiently.

Enduro manufactures these angular contact bearings with chromium steel races hardened to R-62 and polished to a mirror finish for ABEC-5 precision. The balls themselves meet military-level specifications at R-64 hardness and roundness within five millionths of an inch. This precision translates to consistent contact across all bearing surfaces and quiet operation even as the bearings accumulate miles.... Read More