Typical Tools and Supplies Needed

• Park Tool Bottom Bracket Tool: BBT-39
• Park Tool Hammer HMR-2
• Headset Press HHP2 or HHP-3

This article will discuss the removal and installation of the BB30 cartridge bottom bracket bearings. The Park Tool BBT-39 set consists of five pieces. There are four bushings and one remover tool (Figure 1).

Figure 1. BBT-39 set

The BB30 is a threadless bottom bracket shell system using two pressed cartridge bearings. These bearings are replaced when they wear out. However, it is possible to lift the bearing seal while the cartridge bearings are in the shell to clean and grease bearings inside.

Begin by removing cranks, following manufacturer's direction. Look for a one-key release on one arm. Alternatively, there may a two bolt pinch system. Remove one arm and pull spindle and other arm from bottom bracket shell (Figure 2 and 3).

Figure 2. Remove arm using one-key release

Figure 3. Use rubber mallet as necessary to remove arm

Inspect inside bottom bracket shell and note bearing-stop clip. If the clip uses two ears, orient foot of tool so it does not strike the clip (Figure 4).

Figure 4. Avoid "ears" of clip with foot of tool

Insert BBT-39 through one bearing. Tilt tool and guide the foot into the shell (Figure 5).

Figure 5. Guide tool through one bearing and engage foot against opposite bearing

Engage plastic guide bushing into bearing (Figure 6). The guide will keep tool and foot straight as it contacts bearing on opposite side.

Figure 6. Use guide bushing to keep tool aligned

Use hammer such as the HMR-2 and tap end of BBT-39 (Figure 7). Use care not to strike your hand or the frame. Typically, the bearings are a mild press fit and will remove easily. If necessary, rotate tool handle to strike a different point on the bearings.

Figure 7. Strike end of tool to remove opposite bearing

After one bearing is removed, pull tool back through remaining bearing. Place tool through open side of shell and engage plastic alignment bushing. Strike end of BBT-39 and remove second bearing (Figure 8).

Figure 8. Reverse tool and remove second bearing

BEARING INSTALLATION

The BB30 cartridge bearings are a mild interference fit into the shell. The bearing outside diameter is 42mm. The BB30 inside diameter is intended to be 41.96mm. The actual diameter may vary slightly. Bearings are only removed when they are to be replaced.

There is a bearing stop inside bottom bracket shell. These are typically snap rings that fit inside machined groves. It is typically not necessary to remove these rings. If removal is necessary, use a small screwdriver to lift lip of ring (Figure 9). Some designs require the use of snap ring pliers (Figure 10).

Figure 9. Remove clip only if necessary

Figure 10. Use snap ring pliers when necessary

The BBT-39 tool set includes four bushings. The two larger bushings are used for the BB30 standard. The two smaller bushings are used for the Shimano press-bearing design, the "BB90" or "BB95" system. Bushing use a headset press such as the HHP2 or HHP-3.

To install, engage cartridge bearing onto bushing. Bushings will center and align bearings during the pressing. Install bearing, bushing and headset press into shell. Place other bushing with bearing on the remainder of the press.

Figure 11. Bearings, bushings and headset tool

Turn headset press handle until plates contact bushing, bearings, and shell. Stop and double check alignment of bearings into shell and continue to press bearings. Press until both bearings strike stops inside shell. Because bushing will rotate with bearings, it is necessary to hold shaft of headset press (Figure 12).

Figure 12. Press bearings fully to stops inside shell

Remove headset press and pressing bushings. Check inside shell for bearing contact at stop. Install crank according to manufacturer's instructions.