Description
Radial bottom bracket bearing with 52100 high-carbon chromium alloy races combined with grade 5 balls with 90% filling, waterproof high-pressure grease. Designed specifically for cycling applications, the LLU/LLB seal combination on these bearings uses a more protective LLU seal facing outwards towards the elements, to reduce contamination from water or dirt, while the lighter-contact LLB seal (less seal drag) faces inwards. to keep grease in its place. The most common use for this bearing is as a direct replacement for Shimano outer cup bearings when using the Shimano plastic bearing insert. If you wish to avoid using the plastic insert, MR 2437 is the correct bearing for the job.