Remove A Bike’s Square Tapered Crank

Introduction

The commonest type of cranks are aluminium, with square holes that fit onto a tapered square section axle. A nut or a bolt pulls the crank onto the taper to jam it on. They usually need a special tool called a crank-puller or crank-extractor to pull them off the axle.

Pro Tip

Sometimes there will be a dust cap covering the access to the square tapered crank bolt. Unscrew or prize this out.

Step 1

Unscrew The Bolt/nut

Depending on the fitting of the square tapered crank bolt or nut, use either a socket or hex key to unscrew it. Make sure you remove any washer that’s under the head of the bolt.

Step 2

Retract The Bolt From The Crank-puller

A crank-puller is a unit that screws into the threads on the inside of the square tapered crank holes. A bolt that runs through it that jams against the axle to force the square tapered crank off the tapered axle. Retract the bolt from the crank puller. Almost all square tapered cranks use the Italian standard 22mm thread but some old French ‘Stronglight’ or ‘T.A.’ cranks need a different crank-puller.

Step 3

Mount The Crank-puller

Check the threads on the inside of the square tapered crank hole are clean and apply a smear of grease. Screw the crank-puller into the threads, do this carefully as the threads on the aluminium square tapered crank are soft and easily damaged. Finger strength is usually enough.

Step 4

Drive The Bolt into the square tapered crank

When the crank-puller is fully in the square tapered crank, screw in the bolt on the crank-puller, it will jam against the axle and force the crank off the taper.