MR 18307 LLU/LLB Abec5

This ABEC-5 bearing features deep-groove design races, with Grade 10 balls, dual-lip, labyrinth, full-contact LLU seals facing outwards to withstand daily abuse of use and the elements, and lighter-contact LLB seals facing inwards to contain the 90% fill Mobil XHP 222 high-pressure water-proof synthetic grease. CN clearance specification is best for looser press-fit bearing bores.

A radial bearing generally used as a hub bearing, as a bottom bracket bearing for some older square taper BBs, and can be used as a pivot bearing though the MAX-type version of this bearing is better suited for suspension use. Quite often this bearing replaces bearings marked 6903 in front hubs from DT Swiss, Giant and Bontrager, though the ID of this bearing is 1mm larger than standard 6903.