Bottom Bracket Service: When and How to Replace

Bottom bracket maintenance keeps your crankset spinning smoothly. Creaking, clicking, or rough pedaling indicates bottom bracket issues.

Quick Answer: Remove cranks using appropriate tool (hex key or crank puller), unscrew bottom bracket cups with BB tool, clean threads, apply fresh grease, and reinstall to manufacturer torque specs. Sealed cartridge BBs get replaced rather than serviced.

Diagnosing BB Problems

Spin the cranks with the chain removed. Grinding or notchy rotation indicates bearing wear. Lateral play when pushing the crank side-to-side shows loose installation or worn bearings.

Creaking during pedaling may come from the BB or other sources. Eliminate pedals, saddle, and frame flex before assuming BB failure.

Removal Process

Remove both crank arms first. Threaded BBs require a specific spline tool matching your BB type (Shimano, SRAM, Campagnolo). Turn the drive-side cup counterclockwise (reverse thread) and non-drive side clockwise.

Press-fit BBs need bearing press tools or specialty removal tools. Attempting removal without proper tools damages frame threads and bearing cups.

Installation Tips

Clean all threads thoroughly and apply anti-seize compound or waterproof grease. Hand-thread cups to ensure proper alignment. Tighten to specified torque—over-tightening damages threads, under-tightening allows creaking.

Most sealed cartridge BBs last 5,000-10,000 miles depending on conditions. Replace rather than attempting to service sealed bearings.