How To Remove Bicycle Crank Bearings

Removing bicycle crank bearings is not one universal job. First identify the crank and bottom-bracket standard, then remove the crank with its specified procedure and use the matching tool for a threaded, press-fit, adjustable cup-and-cone, or one-piece bottom bracket.

Stop if you cannot identify the system, the frame is carbon, the cup or bearing is seized, or a tool will not engage fully. Incorrect pullers, drifts, and turning directions can ruin a crank, bottom-bracket cup, or frame shell.

Crank bearings or pedal bearings?

The bearings that let the crank rotate sit in the bottom bracket at the frame’s bottom-bracket shell. Pedal bearings sit inside each pedal.

Symptoms near the crank can also come from loose pedals, chainring bolts, crank fasteners, a seatpost, rear hub, or frame joint. Diagnose before disassembly.

Common bottom-bracket symptoms include:

• Side-to-side crank play
• Roughness while turning the crank with the chain removed
• Knocking at the bottom-bracket shell
• Corrosion or contaminated seals

A click alone does not prove the bottom bracket is bad.

Identify the crank system

Park Tool’s crank identification and removal guide separates the common systems and routes each to the correct procedure.

Typical categories include:

• Two-piece external-bearing crank: One arm detaches, and the spindle is attached to the other arm
• Three-piece crank: Both arms attach to a separate bottom-bracket spindle
• Self-extracting crank: A retaining cap pulls the arm as its bolt loosens
• Square-taper or splined crank: Often requires the correct crank puller
• One-piece crank: The crank passes through serviceable cups and bearings
• BMX multi-piece crank: Uses model-specific spindle and fasteners

Record the crank and bottom-bracket model numbers. Check the component and frame manuals for removal order, preload parts, spacers, seals, thread directions, and torque.

Tools vary by standard

Depending on the system, the job may require:

• Hex or Torx bits
• Torque wrench
• Crank puller with the correct tip
• Preload-cap tool
• Bottom-bracket cup socket or wrench
• Pin spanner
• Press-fit bearing extractor
• Bearing press and correctly sized drifts
• Soft mallet where specified

An improvised punch can damage a press-fit shell or drive a bearing out crooked. A cup tool that only partly engages can strip the splines.

Step 1: Remove the pedals and chain

Remove the pedals if they obstruct safe handling. Remember that the left pedal has a reverse thread. Our Shimano pedal removal guide explains the directions and stop conditions.

Pedals with internal hex fittings need the orientation shown in our Allen-wrench pedal guide. If corrosion or thread damage prevents movement, use the stop conditions in the stuck-pedal guide rather than forcing the crank.

Shift or remove the chain according to the drivetrain manual. Protect the frame from the chain and keep it clear of the work area.

Step 2: Remove the crank arms

Follow the exact crank procedure.

Two-piece crank

Release the non-drive-side fasteners in the stated sequence, remove any safety plate or preload cap, then slide the spindle through the bearings. Do not hammer the spindle unless the crank maker permits a soft-mallet procedure.

Square-taper or splined crank

Remove the crank bolt, thread the correct puller body fully into the arm, then turn the puller driver against the spindle. A puller with the wrong tip can damage the crank or bottom bracket.

Self-extracting crank

Confirm the retaining cap is installed and compatible. Loosening the crank bolt against that cap extracts the arm. Do not remove the cap first unless the manual says to.

One-piece or BMX crank

Use the model-specific sequence. One-piece cranks use locknuts, keyed washers, adjusting cones, and loose or caged bearings; BMX systems vary widely.

Step 3: Remove the bottom bracket or bearings

After the crank is out, identify whether the bearings are part of a removable threaded unit, pressed into the frame, or serviceable in cups.

Threaded bottom bracket

Use the matching cup tool and verify each side’s thread direction. Thread direction depends on the shell standard. Park Tool maintains a separate threaded bottom-bracket procedure because not every cup loosens the same way.

Seat the tool completely and keep it square. Stop before splines round or the tool slips.

Press-fit bottom bracket

Support the frame and use an extractor that contacts the intended bearing or cup surface. Drive or pull the bearing evenly. Park Tool’s press-fit bottom-bracket guide illustrates system-specific removal and installation tools.

Repeated press-fit removal can affect the frame interface. Follow the frame maker’s service limits.

Adjustable cup-and-cone or one-piece system

Keep track of locknuts, washers, cones, cups, bearing retainers, orientation, and ball count. Inspect the bearing races. Pitted cups and cones need replacement, not only fresh grease.

Inspect before installing replacements

Clean only with materials approved for the frame and components. Inspect:

• Bearing smoothness and play
• Spindle wear
• Cup splines and threads
• Crank interfaces
• Shell threads or press-fit bores
• Seals, spacers, and preload parts
• Frame cracks, corrosion, or ovalization

Installation requires the correct compound, orientation, press tools, preload, and torque. Do not reuse a single-use fastener or bearing if the manufacturer prohibits it.

Frequently asked questions

Can I replace only the crank bearings?

Sometimes. Some systems accept replaceable bearings; others use a cartridge or cup assembly replaced as a unit. Identify the exact bottom bracket first.

Which way does a bottom bracket loosen?

It depends on the shell standard and side. Never assume. Check the frame or bottom-bracket manual before applying force.

Do press-fit bearings need a press for installation?

Usually they require a correctly aligned press and matching drifts. Hammering a new bearing can damage it or the frame.

Bottom line

Correct identification is the most important step. Remove the crank using its own system, then service the bottom bracket with tools that fully match the cups, bearings, and frame. When the standard or condition is uncertain, a bike shop is cheaper than a damaged crank or frame.