How To Change Bike Pedals

Changing your bike pedals is a fundamental maintenance skill that every cyclist should know. Whether you're upgrading to a new set, replacing worn-out ones, or switching between flat and clipless styles, this guide provides clear, practical steps to get the job done correctly. The key is understanding that the left and right pedals are threaded differently to prevent them from loosening as you ride. We'll walk you through the process safely, ensuring you have the right tools and technique to avoid damaging your bike's crank arms.

Fast Answer

Right Pedal (Drive Side): Loosen anti-clockwise, tighten clockwise (standard thread).
Left Pedal (Non-Drive Side): Loosen clockwise, tighten anti-clockwise (reverse thread).
Tool Needed: A 15mm pedal spanner or a 6mm/8mm Allen key.
Key Step: Always apply bike grease to new pedal threads before installing.

10-20 minutes Time needed

Easy Difficulty

Reverse-threaded left pedal Watch out for

Before You Start

Gathering the right tools and doing a quick check will make this job much smoother and prevent costly mistakes. You don't need a lot, but using the correct items is crucial for success.

What You Need

A set of new pedals: Ensure they are compatible with your bike. The vast majority of modern bikes use a 9/16" x 20 tpi thread size. Some older bikes or children's bikes may use a 1/2" size.
15mm pedal spanner: This is a long, thin spanner designed specifically for the narrow flats on a pedal axle. A standard 15mm spanner is often too thick to fit.
6mm or 8mm Allen key: Many modern pedals are installed and removed using an Allen key socket on the end of the axle, accessible from the back of the crank arm. Check your new and old pedals to see which tool you need.
Bike grease: Essential for preventing the pedal threads from seizing inside the crank arm over time. Any specific bicycle assembly grease or anti-seize compound will work.
Clean rags or paper towels: For cleaning old grease and dirt from the crank arm threads and for general cleanup.
(Optional) Protective gloves: Bike drivetrains are greasy. Gloves will keep your hands clean.
(Optional) Bike work stand: This makes the job easier by holding the bike securely at a comfortable height, but it is not essential.

Check first: Your new pedals must be marked 'L' for Left and 'R' for Right. They are not interchangeable. Installing them on the wrong side will permanently damage the threads in your crank arms.

Step-by-Step Instructions

Follow these steps carefully, paying close attention to the direction you turn the spanner for each pedal. A simple memory aid for loosening is to think of the chain moving backwards; the spanner should always move towards the rear of the bike to loosen a pedal.

Position Your Bike and Right-Side Crank

First, secure your bike. If you have a work stand, clamp the bike in place. If not, lean it securely against a wall. Shift the bike into its largest chainring at the front. This serves two purposes: it gives you a less-sharp surface to hit your knuckles on if the spanner slips, and it tightens the chain, which helps hold the crank in place.

Rotate the crank arms so the right-side (drive-side) crank arm is pointing forward, in the 3 o'clock position. This alignment provides the best leverage for pushing down on your tool to loosen the pedal.

Remove the Right-Side Pedal

The right-side pedal uses a standard thread, so the familiar rule of "righty-tighty, lefty-loosey" applies. To loosen it, you will turn it anti-clockwise.

If using a pedal spanner, fit it onto the flats of the pedal axle between the pedal body and the crank arm. Ensure it has a firm, secure grip. Position the spanner so you can push straight down towards the ground. Apply firm, steady pressure. It may take a significant amount of force to 'crack' it free, especially if it was installed without grease.

If using an Allen key, insert the long end into the socket on the back of the crank arm. Again, apply downward pressure towards the rear of the bike. Once loosened, you should be able to unscrew the pedal the rest of the way by hand.

Tip: If a pedal is very stubborn, try extending your leverage by carefully sliding a metal tube over the handle of your spanner. Be cautious not to let the tool slip and damage the bike or yourself.

Remove the Left-Side Pedal

This is the crucial step where people often get confused. The left-side (non-drive-side) pedal is reverse-threaded. This means you must turn it clockwise to loosen it and anti-clockwise to tighten it.

Rotate the cranks so the left-side arm is now pointing forward in the 3 o'clock position. Fit your spanner or Allen key in the same way you did for the right side. Apply firm, downward pressure, which will turn the pedal axle clockwise, loosening it. The same logic applies: you are pushing towards the rear of the bike to loosen the pedal. Once it breaks free, finish unscrewing it by hand.

Clean the Crank Arm Threads

With both pedals removed, take a clean rag and wipe out the threaded holes in both crank arms. Remove all the old grease, road grit, and any metal shavings. A clean surface is essential for installing the new pedals smoothly and ensuring they don't seize in the future. If the threads are particularly grimy, you can use a small amount of degreaser on the rag, but ensure the area is dry before proceeding.

Prepare and Identify the New Pedals

Unpack your new pedals. Take a moment to positively identify the left and right pedal. They are almost always stamped with a small 'L' and 'R', or sometimes indicated by grooves on the left pedal's axle. Double-check this now to prevent a costly mistake. Placing the pedals on the floor on the side of the bike they belong to is a good way to keep them organised.

Grease and Install the New Right-Side Pedal

Take the pedal marked 'R'. Apply a thin, even layer of bike grease to the entire threaded portion of the axle. This simple step is vital for easy removal next time and prevents corrosion between the steel axle and alloy crank.

Carefully insert the pedal axle into the right-side crank arm. Start threading it by hand, turning it clockwise. It should screw in smoothly for several rotations. If you feel any resistance, stop immediately, back it out, and try again to ensure you aren't cross-threading it. Once it's hand-tight, use your spanner or Allen key to snug it up. It needs to be firm, but there's no need to apply excessive force. A good, firm turn is sufficient.

Grease and Install the New Left-Side Pedal

Now take the pedal marked 'L'. Apply grease to the threads just as you did for the right pedal. Position it in the left-side crank arm.

Remembering the reverse thread, begin screwing it in by hand, turning it anti-clockwise. Again, it should thread in easily. If it binds, stop and realign it. Once it is hand-tight, use your tool to tighten it firmly. The tightening direction will feel counter-intuitive, but it's correct for this side.

Tip: An easy way to quickly thread pedals by hand is to hold the pedal axle still and turn the crank forward with your other hand. The pedal will screw itself in.

Quick Reference

Task	Direction to Turn Tool	Reason
Removing Right Pedal	Anti-Clockwise (Lefty-Loosey)	Standard threading.
Removing Left Pedal	Clockwise (Righty-Loosey)	Reverse-threaded to prevent loosening while pedalling.
Installing Right Pedal	Clockwise (Righty-Tighty)	Standard threading.
Installing Left Pedal	Anti-Clockwise (Lefty-Tighty)	Reverse-threaded for security.

Common Problems When You Change Bike Pedals

My Pedal is Completely Stuck

This is the most frequent issue, usually caused by pedals being installed without grease. First, double-check you are turning the tool in the correct direction for that side. If you are, you simply need more leverage. Try using a spanner with a longer handle. You can also spray a penetrating oil (like GT85 or WD-40) where the pedal axle meets the crank and let it sit for 15-30 minutes before trying again. Applying your body weight effectively is key—stand over the bike and push down with force.

The New Pedal Won't Start Threading

If a new pedal won't screw in easily by hand for the first few turns, stop immediately. The most likely cause is that you are trying to install the left pedal on the right side, or vice-versa. Check the 'L' and 'R' markings on the pedals and ensure you have the correct one for the side you are working on. The second most likely cause is that you are holding it at an angle, causing it to cross-thread. Back it out and carefully realign it so it's perfectly straight with the hole.

My Spanner Keeps Slipping Off

This usually happens when using a standard adjustable spanner or one that is too thick. A proper 15mm pedal spanner is thinner and grips the narrow flats more securely. Ensure the spanner is pushed on as far as it will go. If the flats on the old pedal axle are rounded off, you may need to use a locking wrench to get a secure grip for removal.

Advanced Tips for Changing Bike Pedals

Using a Torque Wrench

For carbon fibre crank arms or for mechanics who prefer precision, using a torque wrench is the best practice. Most pedal manufacturers recommend a tightening torque of around 35-40 Newton metres (Nm). Overtightening can damage the soft aluminium or carbon threads of a crank arm, while under-tightening can cause the pedal to wobble and damage the threads over time. Always check the specific recommendation from your crank or pedal manufacturer.

When to Use Pedal Washers

Some pedals come with very thin washers. These are not always necessary but can be useful in two situations. First, they protect the surface finish of expensive crank arms from being scratched by the pedal axle. Second, they can provide a small amount of extra clearance between your shoe and the crank arm, which can be beneficial for some rider's biomechanics. If your old pedals had washers, it's generally a good idea to install the new ones with washers too.

Dealing with Damaged Crank Threads

If you discover that the threads inside your crank arm are damaged, do not try to force the new pedal in. This will only make the problem worse. Take the bike to a reputable local bike shop. They have a special tool called a tap that can be used to 'chase' or re-cut the threads. In severe cases, they may be able to install a threaded insert (a Heli-Coil) to save the crank arm. This is a repair best left to professionals.

How To Change Bike Pedals FAQ

Why is the left bike pedal reverse-threaded?

The left pedal is reverse-threaded to counteract a mechanical phenomenon called precession. As you pedal, the bearing friction creates a tiny rotational force on the pedal axle in the opposite direction of the pedalling motion. On the left side, this force would slowly unscrew a normally threaded pedal. By reversing the thread, this force instead works to constantly tighten the pedal, keeping it secure.

How often do I need to change my bike pedals?

There is no set mileage or time limit. You should change your pedals if the bearings feel rough, gritty, or have excessive play (wobble), if the pedal body is significantly damaged from rock strikes, or if you simply wish to upgrade to a different style (e.g., from flat pedals to clipless pedals for better efficiency).

Can I use a regular 15mm spanner?

Sometimes, but often a standard spanner is too thick to fit into the narrow space between the pedal body and the crank arm. A dedicated pedal spanner is an inexpensive and highly recommended tool for any home mechanic as it is designed for this specific job, providing better fit and leverage.

Final Checklist for Changing Bike Pedals

Old right-side pedal successfully removed by turning anti-clockwise.
Old left-side pedal successfully removed by turning clockwise.
Threaded holes in both crank arms have been wiped clean.
A thin layer of grease has been applied to the threads of both new pedals.
The new pedal marked 'R' is installed on the right (drive) side, tightened clockwise.
The new pedal marked 'L' is installed on the left (non-drive) side, tightened anti-clockwise.
Both pedals are tightened to be firm and snug, without using excessive force.
Rotate the cranks a few times to confirm the pedals spin smoothly.