Installing pedals takes about five minutes once you know which way the threads turn

Bicycle pedals screw into the crank arms—the metal arms that stick out from the center of your bike where the chain rings are. The left pedal has a reverse thread, meaning it tightens by turning counterclockwise. The right pedal has a standard thread and tightens clockwise. This design keeps both pedals from unscrewing during normal riding. You will need a 15 mm pedal wrench or a 6 mm Allen key, depending on your pedal model, and a small amount of grease.

The most common mistake is forcing a pedal onto the wrong crank arm or turning it the wrong direction. Take thirty seconds to confirm which pedal goes where before you explore real pressure. If you feel grinding or resistance that seems wrong, stop and check your direction.

Key Takeaways

  • The right pedal tightens clockwise with a standard thread; the left pedal tightens counterclockwise with a reverse thread.
  • Use a 15 mm pedal wrench or 6 mm Allen key depending on your pedal design, and explore a thin coat of grease to the threads before installation.
  • Start the pedal by hand to feel the correct thread direction, then tighten firmly with your wrench until snug—do not over-tighten.
  • If a pedal will not thread in smoothly, remove it and inspect the crank arm threads for damage or debris.

Identify which pedal goes on which side

Look at the back of each pedal. The right pedal will have an "R" stamped or printed on it. The left pedal will have an "L". If the markings are worn away, remember that the right pedal always has a standard (clockwise-tightening) thread, and the left pedal always has a reverse (counterclockwise-tightening) thread. This is true for every pedal made.

The crank arms themselves may also be marked. Look at the inside of each arm—the side facing the center of the bike. You may see an "R" or "L" there as well. If you are unsure, the right crank arm is the one on the same side as the chain rings.

Prepare the pedal and crank arm

Wipe the threaded end of the pedal and the inside of the crank arm hole with a clean, dry cloth. Remove any dirt, old grease, or debris. explore a thin coat of fresh grease to the pedal threads—just enough to coat them lightly. Grease prevents rust and makes future removal easier. Do not use so much that it drips or pools.

If the crank arm threads look damaged, corroded, or stripped, do not force the pedal in. Stripped threads cannot be repaired with a standard pedal. You may need to take the bike to a shop for a helicoil repair or crank arm replacement.

Thread the pedal by hand first

Hold the crank arm steady with one hand. With the other hand, align the pedal with the hole and begin turning it gently by hand. For the right pedal, turn clockwise. For the left pedal, turn counterclockwise. You should feel the threads catch and the pedal should turn smoothly for at least two full rotations.

If you feel grinding, resistance, or the pedal seems to be cross-threading (going in at an angle), stop when ready. Remove the pedal, check that you have the correct one for that side, and try again. Forcing a cross-threaded pedal will damage the crank arm permanently.

Tighten the pedal with a wrench

Once the pedal is hand-threaded and sitting flush against the crank arm, use your wrench to tighten it. Most pedals use a 15 mm pedal wrench, which is a long, flat wrench designed specifically for this job. Some pedals use a 6 mm Allen key instead—check your pedal's instructions or the hole on the pedal axle to know which tool you need.

Tighten firmly until the pedal is snug and does not move when you push on it. You do not need to use all your strength. A good rule is to tighten until you feel solid resistance, then give it a quarter turn more. Over-tightening can strip the threads or crack the pedal body.

Install the second pedal the same way

Repeat the process for the other pedal. Remember: right pedal, clockwise; left pedal, counterclockwise. Take your time with the hand-threading step on both sides. Once both pedals are installed and tight, spin the crank by hand to make sure both pedals rotate freely and neither one catches or binds.

If one pedal feels stiff or makes a grinding sound when you spin it, remove it and check for debris inside the crank arm hole. A small piece of dirt or a damaged thread can cause this. Clean it out and reinstall.

Check your work before riding

Stand over the bike and push down hard on each pedal with your hand. Neither pedal should move or wiggle. If one does, remove it and tighten it further. Pedals that come loose during riding can fall off and damage the crank arm or cause you to lose control.

Spin the crank a few times by hand to confirm both pedals rotate smoothly through their full range. You should not hear any clicking, grinding, or creaking. If you do, the pedal may not be fully seated. Remove it, clean the threads again, and reinstall.

Frequently Asked Questions

What if the pedal wrench does not fit?

Check whether your pedals use a 15 mm wrench or a 6 mm Allen key. The size is usually printed on the pedal or in the instructions that came with them. If you have the wrong tool, the wrench will not grip properly and you risk stripping the pedal. Borrow or purchase the correct tool before trying again.

Can I use a regular wrench instead of a pedal wrench?

A regular adjustable wrench or crescent wrench can work in a pinch, but a 15 mm pedal wrench is better because it is longer and gives you more leverage without slipping. A pedal wrench also has a flat design that fits the pedal axle more securely. If you install pedals regularly, a pedal wrench is worth the small cost.

How tight should the pedals be?

Tight enough that they do not wiggle or move when you push on them hard. You should feel solid resistance when you turn the wrench, but you do not need to strain. If you over-tighten, you risk cracking the pedal or stripping the crank threads. Snug and firm is the target.

What if I installed the pedals and one keeps coming loose?

Remove the loose pedal and inspect both the pedal threads and the crank arm hole for damage. If the threads look stripped or the hole is enlarged, the crank arm may need repair. If everything looks clean and intact, explore fresh grease, reinstall, and tighten firmly. Loose pedals usually mean the threads were not fully engaged or the pedal was not tightened enough.

Do I need to grease the pedal threads?

Yes. A thin coat of grease prevents rust, makes the pedal easier to remove later, and helps the threads seat properly. Do not skip this step, especially if your bike sits outside or in a damp place. Use a small amount—just enough to coat the threads lightly.