Nav Menu

Cartridge Bottom Brackets


There are different types of bottom brackets for bicycles, but one of the most reliable options is the cartridge bottom bracket. Commonly found on older and entry-level bikes, a cartridge bottom bracket usually has two main components: the cartridge and the lockring. The cartridge contains the sealed bearings and spindle and is usually threaded into your frame's right (or drive side). The lockring supports the opposite end of the cartridge and is usually threaded into your frame's left (or non-drive side).

Advantages of Cartridge Bottom Brackets

The main advantage of a cartridge bottom bracket is that it is designed to be maintenance-free and durable. The sealed bearings prevent dirt, water and other contaminants from entering and causing wear and tear. The cartridge also eliminates the need for adjustment, as it has a fixed spindle length and chainline. This means you don't have to worry about fine-tuning your bottom bracket or replacing worn-out parts.

However, this also means that when a cartridge bottom bracket does fail, you have to replace the whole unit rather than just individual parts. A common sign of a failing bottom bracket is when you hear creaking or grinding noises from your crankset or feel play or wobble in your pedals. When this happens, you will need a special tool called a bottom bracket tool to remove and install a new cartridge.

Different Bottom Bracket Types

Cartridge bottom brackets come in different sizes and specifications depending on your bike's frame, crankset, and chainline. You will need to measure your existing bottom bracket or check with your bike's manufacturer to find out what size you need. Some common measurements are shell width (the width of your frame's bottom bracket shell), axle length (the length of your spindle) and threading type (the direction of threading on each side).