Cycle Systems Academy

BB - a common acronym for Bottom Bracket

Although you can often adjust a unit to remedy problems, nevertheless any mechanic should really be opening the BB unit (if possible) to inspect for damage.This will give you a better idea of what is needed.

WORKSHOP TIP: If the bearings or bearing surfaces are worn or damaged, or indeed if there is simply too much dirt or too little grease in the unit, no amount of adjustment will make the unit work. In which case, a refurbishment or replacement will be necessary. Also, it may be the case that unevenly worn parts will cause increased wear to any new part, not really fixing the problem or making the repair worthwhile and making total replacement of the BB unit the only feasible option.