How To Remove The Crank Arm From An Exercise Bike

By Robbie Ferri CPT

CPT & Indoor Cycling Instructor

Exercise bikes are a lot of fun, and having one at home can keep you fit and give you an hour to escape day-to-day life. Like anything mechanical, exercise bikes can break and, over time and require maintenance. 

We get asked many questions here at Girl Bike Love about how to work on exercise bikes, and one that comes up often is, “How do I remove a crank arm from an exercise bike?” In this article, we’re going to be telling you everything you need to know by discussing: 

• What Is A Bike Crank?
• Why Might You Need To Remove A Bike Crank Arm?
• Our Step By Step Guide On Removing A Bike Crank Arm

What Is A Bike Crank?

A bike crankset is a component that connects the bottom bracket of the bike to the pedals. It gives the rider leverage on the pedals and the ability to rotate the crankset. The rotation of the crankset turns the chain or belt and can spin the rear flywheel. 

The bike crank arm is a part of the crank which can be separated and removed. On many new spin bikes, it’s common to have to attach these cranks yourself. Bike crank arms have the ability to be taken off and swapped out for many reasons. 

Why Might You Need To Remove A Bike Crank Arm?

There are many reasons why you need to remove or install a bike crank. Here’s what you need to know:

To Replace It

Cranks arms are not typically something you will change regularly. If the pedals cross-threaded the spindle, indoor cyclists must swap a bike crank arm. This is because when the pedal is installed wrong or has come loose and been ridden. 

To Swap Out For Other Cranks

Some exercise bikes actually have the ability to remove and swap to different cranks. You might want to have longer cranks for more leverage or shorter cranks for a better bike fit. 

Better Storage And Transport

If you’re looking to put your spin bike away for a long time and need to save as much space as possible, you can break it down into pieces. Not only does removing the bike crank arms save space, but it also takes the pedals off simultaneously. 

Our Step By Step Guide On Removing A Bike Crank Arm

Now for the fun bit, let’s teach you how to remove a modern bike crank arm. Here’s our step-by-step guide. We will do this on a standard modern bike crank arm, although other types may differ. The bike model is a Sunny SF-B1709.

What Tools Will You Need?

To remove a crank, all you will need is an Allen key set and possibly a screwdriver. We recommend a long Allen key set as they offer much more leverage. 

Step One: Locate The Crank Bolt

The first thing you need to do is locate the crank bolt. This will be directly above the crank arm itself at the top. You will find it by going to the center of the cranks, and it will sit on either the left or the right.

Step Two

Loosen The Crank Bolt

Now we need to loosen the bolt itself. You have to take the Allen key, insert it, and then you need to turn it anti-clockwise to undo it. Expect this to be quite tight, as it’s the only bolt that holds everything together on many cranks. 

Many people say to loosen the bolt, but I recommend completely removing it as it is going to help us take the crank arm off fully later. Once out, put it in a safe place, as these can sometimes be unusual threads. 

Step Three

Remove Crank

The last step is to remove the crank itself. Now the bolt is out, it will be looser, but it still might take a bit of persuasion. It comes loose easily by rocking the crank back and forth, but this can take some time. 

If you get really stuck, you can use the screwdriver and put it between the small gap at the top to open the gap, and it will be looser and easier to pull off. Once the crank arm is off, then put the bolt back in but not tightly, and you’re done. 

A Final Note

Thanks for taking the time to read our article. Don’t forget to check out the video on the Girl Bike Love YouTube Channel. All the best from us!