July 20, 2018
Last modified: February 15, 2019

Removing and installing bike pedals might seem like a “no-big-deal” kind of procedure, but if you’ve never changed your own pedals before there are some easy mistakes that could leave you with a stuck pedal and a ruined crank arm. So here is a quick run through the process and some helpful things you should know before changing bike pedals.

At a Glance:

1. Use a pedal wrench or hex key to unscrew the pedals from the crank arms. Right pedals loosen by turning counter-clockwise, left pedals loosen clockwise
2. Apply bike grease to the new pedals and screw them in at an even 90 degree angle. Right pedals tighten by turning clockwise, left pedals tighten counter-clockwise
3. Screw in until each pedal is fully inserted and tight; then hit the road!

Right is Wrong

The first and most important detail you need to know before getting started is that pedals don’t screw right. Or rather, one of them doesn’t. Even though the right-side pedal screws in like anything else, the pedal for your left foot has a left-hand thread, which means it unscrews in the opposite direction that you’re used to. So you have to turn it clockwise to LOOSEN it, and counter-clockwise to TIGHTEN it. (fig. 1)

So why do pedal makers add this extra complication? The reason for the left-handed threading is to counter a mechanical phenomenon called “precession.” Basically, the downward force of your foot on the spindle while pedaling causes the axle to “spin” the opposite way in the crank arm. If the left pedal had regular, right-hand threads, that pedaling force would cause the pedal to loosen and eventually fall off mid-ride. So by threading the spindles to pull back into the crank as you pedal, they stay firmly in place without any additional bolts.

Re-Learning Right and Left

Because the Right and Left pedals have opposing threads, trying to insert and tighten the wrong pedal into the other crank arm’s threads can cause major damage. A right-side pedal may feel like it has caught onto a left crank arm thread, especially if it’s inserted at an angle. But if you try to “power through” thinking that the threads are just tight or coarse, you will effectively cross thread the crank arm’s spindle hole and potentially ruin it. To avoid this costly mixup, most pedal manufacturers now label or stamp their spindles with an “R” or “L,” making them easy to tell apart. (fig. 2a) But if these are missing or have worn off, another easy way to figure this out is to simply hold both pedals side-by-side, spindles up. Then look at the angle of the threads. The threads on a right-side pedal will slope up and to the right, while the left-side pedal threads slope up and to the left. (fig. 2b)

Tools of the Trade

Like most maintenance jobs, having the right tools is the key to a successful pedal swap. All modern pedals will screw into the crank arm using either one of two tools. Most pedals require a pedal wrench, which is a long, thin tool specifically designed to fit the external spindle flats between the pedal and the crank leg (fig. 3). Even though you might already have a regular wrench that fits, a good pedal wrench is not terribly expensive and will save you from a lot of frustration and possibly some bloody knuckles. Trust us on this one, it’s WAY easier. If you are upgrading to high-end pedals, you will most likely just need an appropriately sized hex key, which fits the spindle from the inside of the crank leg (fig. 4). We also recommend having an adjustable torque wrench and bike grease on hand. These will make sure that your pedals are tightened to the manufacturer’s specifications and are easy to remove later.

Step by Step

Now that you have a deeper understanding of this deceptively simple task, let’s go through a detailed guide for how to remove and install bike pedals:

How to take pedals off:

1. Rotate the crank arm for easy access and leverage
2. Place your pedal wrench on the spindle flats or hex wrench into the port on the inside of the crank arm
3. Push hard to loosen the spindle: Clockwise for the left-side pedal, counter-clockwise for the right
4. Continue rotating the spindle until the pedal is free and repeat on the opposite side
   

How to put pedals on:

1. Look for an “R” and “L” stamped or printed on the pedal’s spindle and place on the correct side of the bike. If they’re not marked, check the pedals’ threads: Up to the right goes on the right-side, up to the left goes on the left side
2. Apply some bike grease to the spindle threads
3. Insert each pedal straight into their side’s crank arm at a 90-degree angle. They should easily thread into place
4. Place your pedal wrench on the spindle flats or hex wrench into the ports on the inside of each crank arm
5. Tighten the pedals by turning the right pedal clockwise and the left pedal counterclockwise
6. Once you feel resistance, tighten the pedal to the manufacturer’s specified torque, or about 1/8 of a rotation further to properly secure it

Now you should be all set to go! Be sure to inspect your pedals now and then to make sure they are totally secure. And if you still aren’t sure about how your pedals feel, head to your local shop to have a mechanic double check them. Otherwise, enjoy your next ride, and be sure to check back here for more helpful tips and “How-tos.”