What is a BB shell?
The bottom bracket shell of a bicycle is the part of the frame where the spindle of the cranks go through. The bottom bracket and spindle together form the foundation of the drivetrain on your road bike or mountain bike. The bottom bracket bearings are sometimes referred to as just the bottom bracket as well.
What is an external bottom bracket?
External bottom brackets allow you to have both large bearings and a large, hollow bottom bracket spindle. A large hollow spindle can be designed to be as stiff as a small solid spindle for less weight.
How do you use a Park Tool on a bottom bracket?
For more on tools required, see Bottom Bracket Tool Selection: Press Fit. The Park Tool BBT-30.4 is intended for bottom brackets using bearings with a 30mm inside diameter (30mm diameter spindles). Install the BBT-30.4 driver through one bearing and push it toward the opposite bearing.
Can I use a press fit bottom bracket removal tool?
Many press fit bottom brackets are designed so a removal tool must be seated against the bearing. Striking the tool can cause deformations to the cup and the bearing system, which can negatively affect the performance of the bottom bracket system.
How do I remove the bearings from the bottom of brackets?
Strike the end of the driver repeatedly with a steel hammer to remove the last bearing adaptor. For bottom brackets using bearings with an inside diameter between 22mm to 24mm, use the Park Tool BBT-90.3. Insert the small end of the tool through the bottom bracket. Pull until the expanding end clicks and engages inside the bearing cup.
What tool do you use to remove bottom brackets from bikes?
Bicycle bottom brackets occasionally require removal for service, replacement, or upgrading. The Park Tool BBT-22 is a shop quality tool for installing and removing bottom brackets with tool fittings with 20 splines and a diameter of 32mm.
