How to Remove and Install a Crank
Guidance for removing a Crank and pedal arm from a square taper spindle. When fitting a Crank this is done in reverse order.
Why should you remove the Crankset? If you need to gain access to the bottom bracket. Or when you have play in the bottom bracket spindle. Replacing Chain Rings, upgrading the Crank. A full bike service or restoration.
See video below demonstrating How to Remove and Install a Crank
Tools for Crank Removal and Install
What tools are needed? Before you start this job the correct tool is essential. The tool you need is a crank extractor tool. This is generally a cheap tool, but is a must in any bicycle mechanics tool box. Screw driver for dust cap removal if present. Either Allen Key or Socket Set depending on the type of spindle bolt fitted.
It is good practice once the Crankset has been fitted and ridden for 100 miles to recheck and tighten the bolts. If the Crankset becomes loose ensure not to continue to ride it because this can damage the soft alloy and cause unrepairable damage to the crankset.
Crank Dust Covers
Cranksets are normally fitted with a protective dust cover to protect the internal threads. Plastic covers can generally be prized off using a small screwdriver. Some more expensive cranksets may have a screwable dust cap with either a flat head screwdriver slot or Allen key fitting. Be aware some Campagnolo cranksets do not have any, and have a Allen key bolt direct into the bottom bracket spindle.
Some crank’s and pedal arm’s are fitted with a more modern Allen key bolt fitting which do not have a dust cover To remove crank bolts I will generally use a socket set for this. Part of the extractor tool does have a socket spanner included in the design of the tool. To release the bolts turn anti clockwise. You should be able to undo most of the bolts once loosened with your fingers. Ensure you do not leave any washers that may of been placed onto the bolt when fitted.
Crank Extractor Tool
On the Crankset and Pedal Arm you will notice an internal thread, this is where the crank extractor tool is secured to. Ensure these threads are clean and free from any grit. I generally give this a short spray of lubricant to assist in securing the crank extractor. Slowly screw the tool into either the pedal arm or the Crankset. This should screw down easily turning four of five turns. Ensure this is screwed straight and not at an angle. Using a spanner gently tighten the extractor tool into place.
Now by hand turn the spindle on the crank extractor tool clockwise locating onto the spindle of the Bottom Bracket.
Brace yourself into a position of advantage using a socket set or spanner. Continue to drive down the spindle of the tool clockwise, and in turn driving the crankset or pedal arm away from the bottom bracket spindle.
Once you have achieved the removal unscrew the tool from the pedal arm or crankset using a spanner. Bolts are tightened up between 30-45 newton metres of pressure using a torque wrench when fitting. If you do not own a torque wrench this is quiet a lot of pressure and many vintage bicycle maintenance manuals would recommend just tightening as hard as you can. This is achieved by using a socket set and ratchet handle to achieve the leverage. Use a small amount of grease to the surfaces of the spindle to avoid corrosion when fitting.