How to Remove a Cartridge Bearing Bottom Bracket
Below are instructions for removing a cartridge bearing bottom bracket. It doesn’t take long but there are a few scenarios you have to watch out for. (Note that you must remove your cranks before removing the bottom bracket.)
If you have a 20-tooth splined bottom bracket, you’ll need a Park BBT-22 tool. For eight-notched bottom bracket lockrings, use a BBT-18 tool. (It’s not hard to figure this out – your bottom bracket cups will either have 8 wide notches or 20 narrow ones.)
Step 1: Remove the left-side cup.
In most cases, we’ll start by removing the cup from the left side (non-drive side.) However, if the bottom bracket uses a metal ring on one side and a plastic ring on the other, always remove the metal side first.
We’ll start with the left side…
Insert your BBT-22 completely into the splines of the cup’s lockring. Then, using a large adjustable wrench, turn it counterclockwise to loosen. You can finish removing the cup by hand.
Step 2: Remove the right-side cup.
Now we can remove the right, or drive side, cup. Insert the BBT-22 as before, but this time turn it clockwise to loosen. Then you should be able to pull the whole bottom bracket out.
Step 3: Relax.
You just accomplished a daunting task in two steps, so you can now sit back and relax.
A few warnings: In most bikes, the left side will loosen counterclockwise and the right side will loosen clockwise. This is usually referred to as having “English” threads. However, that’s not the case on every bike. There are French, Spanish, and Italian threads, too, which all work in different manners.