When it comes to cycling, you can benefit so much from knowing how to work on your own bike.
Bike crank removal is one of those jobs that are essential to understand as it plays a vital role in deep cleaning, bottom bracket maintenance, and repairs or replacements to your chainrings – as well as the option to upgrade the chainset itself.
However, though it’s a relatively simple job, it’s worth knowing how to do properly, as you can create headaches for yourself later if you get it wrong!
In this bike crank removal guide, we’ll be walking you through:
- What Is A Bike Crank?
- 4 Reasons To Learn How To Remove Bike Cranks
- What Tools Will You Need To Remove A Bike Crank?
- Bike Crank Removal Explained In 7 Steps
- Robbie’s Video Maintenance Guide: Bike Crank Removal
Let’s get to grips with how to remove a bike crank arm!
What Is A Bike Crank?
“Cranks” can mean a couple of different things to different cyclists.
Technically speaking, the cranks themselves – also known as “crank arms” – only refer to the arms that connect the pedals to the chainrings.
However, the term “cranks” also sometimes gets used by cyclists to refer to the entire crankset (or chainset in the United Kingdom).
The crankset is what we call the chainrings, crank arms, and spider (usually integrated into the crank arms on modern bikes) altogether.
Cranksets come in all different shapes and sizes. Crank arms usually vary in length between 165 mm and 175 mm, and you’ll find some cranksets with two chainrings on, others with just one, and some with three.
Changing your crankset is a great way to customize your bike to suit you perfectly.
4 Reasons To Learn How To Remove Bike Cranks
There are many reasons why you might want to know how to remove a bike crank. Here are the most common:
#1. To Deep Clean The Drivetrain
Every so often, you should give your drivetrain a proper deep clean.
This means taking the time to really pull your bike apart and get into all the tricky spots that get missed on your regular clean. Bike crank removal is part of this!
You might want to completely remove the cranks and other drivetrain components to ensure you get a perfect finish.
#2. To Change It Out For Another
Cranks come in all different sizes, and they can completely change how the bike feels to ride.
You might want to swap out the crank for one with shorter arms or maybe smaller chainrings. This could give you a better fit and different gear ratios.
- Want to know more? Check out Bike Chainrings Explained here!
#3. To Access The Bottom Bracket
Removing the crank is the only way to access the bottom bracket on a bike.
If your bottom bracket needs servicing or is worn out, then you must remove the crank to ensure it can be accessed. Knowing how to remove a bike crank means you can access the bottom bracket.
#4. To Upgrade
The last reason you might want to swap out your crank is to upgrade.
A lighter, faster crank might benefit you if you are planning to race. You can save up to 300 g using a performance crank like a Dura-Ace.
There’s also the option of using an Oval Chainring, the value of which is still subject to debate – although they’re the choice of many professionals.
What Tools Will You Need To Remove A Bike Crank?
Before we start showing you how to remove bike crank arms, it’s important that we have the tools to complete the job.
In this article, we’re working on a Shimano Hollowtech II crank, one of the most common types. Surprisingly, you need very little to remove these modern cranks.
Here’s what we recommend you have ready:
- Allen Key Set (typically 5 mm is all you’ll need)
- Crank Removal Tool (specific to your cranks)
- Small Flathead Screwdriver
- Bike Stand (optional)
This will be everything you need to complete the job!
Bike Crank Removal Explained In 7 Steps
Here’s our How-To guide when it comes to crank removal.
Take your time when doing this job – it’s simple, but the last thing you want is to rush it and end up rounding off bolts!
Step #1. Preparation
Find a safe place to work and have a place to keep your tools, so you don’t end up misplacing them.
If you’re using a bike stand, you will want to get the non-drive side of the bike in front of you, as this is where you’re going to be starting.
A common mistake many cyclists make is they take the crank off with the pedals still on. Be warned that it’s very difficult to remove the pedals from the crank arms if you’ve already taken them off the bike!
If you’re going to need the removed, take them off now. Check out our How To Remove Bike Pedals guide to learn more!
Step #2. Loosen The Crank Bolts
Now we are going to need to loosen off the crank bolts.
These bolts work in a unique way, and you have to be careful when removing them as they require a certain process to release properly without being rounded.
Using the 5mm Allen key, start on one side of the non-driveside crank arm and undo it half a turn anti-clockwise. Swap to the bolt on the other side and then go half a turn. Keep repeating this process until both are loose.
The reason we need to do this is because of how it clamps. As one bolt loosens, the other naturally tightens. A common error many cyclists make is completely undoing one side and the other becoming stuck.
Don’t worry about completely removing the bolts – they only need to be loose. These are bolts you are not going to want to lose!
Step #3. Remove The Main Crank Bolt
It’s now time to remove the main crank bolt.
You will need to use the crank bolt removal tool for this job. As the crank bolts on the outside are loose, this should come out easily just by turning the tool with your hand.
You will need to go anti-clockwise, and this bolt has a surprising amount of thread. They are generally only made of plastic, and the crank needs this to be set up properly, so ensure that you don’t lose it or break it.
Step #4. Release The Safety Clip
Next, we must remove the safety clip on the non-drive side crank arm.
For this, you will need the small flathead screwdriver. The clip is situated in a small gap at the base of the crank arm.
Using the screwdriver push the clip away from the center of the crank. This should be very loose and easy to do. It might be a bit more challenging if it’s full of dirt or grime.
Step #5. Remove The Non-Drive Side Crank Arm
Now it’s time to remove the non-drive side crank arm.
With the crank safely bolts loose, the main crank bolt out, and the safety clip up, you should be able to jiggle the pedal arm loose easily.
If it feels challenging, we recommend that you just check that you have done the preceding steps correctly, and only then apply more force to ensure it comes off.
Step #6. Unhook The Chain
You will now need to turn the bike around, so you’re looking at the driveside.
You might notice this side generally has no bolts or anything that can be undone. That’s because it was all on the non-drive side you have taken off.
Shift the chain into the smallest chainring, then take the cloth, grab the chain, remove it from the chainring, and hang it on the shell of the bottom bracket. This will keep it out of the way when we remove the rest of the crank.
Step #7. Pull The Crank Out
The last step is to pull the crank out of the bottom bracket itself.
With nothing keeping it connected to the bike, it should come free easily without too much force.
Take the cloth and wrap it around the chainrings to protect your hands. Then place your thumbs on the frame and fingers on the crank. You will need to pull the crank towards you while pushing with your thumbs.
The crank should release easily. If it doesn’t, you might need to use a blunt object and lightly tap it from the non-driveside – but only as a last resort.
Robbie’s Video Maintenance Guide: Bike Crank Removal
Check out the BikeTips YouTube Channel here for walk-through bike maintenance guides and more!
Now you know How To Remove a Bike Crank Arm…
Bike crank removal is a very useful skill to learn when it comes to bike maintenance.
It can help you keep your drivetrain in optimal condition giving you excellent performance, and can save you a fortune in bike shop labor.
Removing a crank is a job that will have to be done fairly often. It gives you access to the bottom bracket, and you often need to remove the crank to remove the chainrings.