Only use retainer glue when there is zero press fit or interference fit of your bearing into a bearing bore. This can happen with years of wear on aluminum bearing cups. If the bearing easily drops out of the bore, or you can easily press the bearing in with your fingers and no tools, a very small coating of Loctite or bearing retaining compound can help keep this point quiet. It is common practice to mount bearings this way. On some bikes and components, you will simply be replacing what was already there. Please note: Be careful that the retaining compound never overflows onto surfaces where it doesn't belong, such as the face of the bearing or anywhere near the lips of the seals, as this can effect optimal bearing performance.