Equal Rights for BBs!

The unsung hero that keeps your pedals turning

Dorene O’Malley, Cane Creek Cycling Components

Maybe more than any part on a bicycle, the bottom bracket (BB) is used and abused but goes along unnoticed. That is until it makes a lot of creaking and crunching sounds, by which time it is likely beyond salvage. Bicycle frames have “BB shells” into which fit an assembly consisting primarily of two bearings, and this assembly is called the “BB”.

Every time the rider pedals, the turning motion and force are handled by the BB. Just think, the average rider makes a pedal revolution about 80 times per minute. During a two-hour ride, accounting for coasting downhills, the BB bearings turn about 7,000 times! Then there’s the location of the BB – it is close to the ground and the direct recipient of mud, sand, water, and stuff flying off of the front tire. And many times it has suspension parts surrounding it that collect said stuff. So the BB lives in a nasty neighborhood. If your bike makes creaking sounds when you push hard on the pedals, there’s a good chance that your BB needs attention or replacement.

Cleaning your bike regularly is a good idea, but directing water straight at the BB can force more bad stuff inside. It’s best to wipe of most of the dirt and debris and then use a sponge to clean the area with only a light easy flow of water to rinse the area clean. Directing a pressure washer nozzle at the BB is a sure way to shorten its life. It is also a good idea to at least have your BB inspected, if not replaced when you get a new chain.

While all BBs deserve equal rights, they were not all born equal. While a key part, bike companies don’t like to spend more than they have to on parts that are not visible and/or misunderstood. Many BBs are made with cheap materials like plastic, very few new bikes have stainless steel bearings and almost none have ceramic balls in the bearings, and warranties are only one, maybe two years in length and usually exclude the bearings. However, high-quality CNC aluminum BBs with full stainless steel or stainless with ceramic balls are available when the time comes to replace the BB that came in the bike.