You can change bike pedals yourself with two wrenches and no special tools

Bike pedals come off and go on the same way every time: you turn the wrench counterclockwise to remove the old pedal, then clockwise to install the new one. The only trick is that the left pedal has a reverse thread, meaning it tightens when you turn it the opposite direction from the right pedal. Once you know that, the job takes about 15 minutes and costs nothing beyond the new pedals themselves.

You do not need to remove the crank arm, take the bike to a shop, or buy special equipment. A 15mm wrench (or an adjustable wrench that fits) is all you need, plus maybe a second wrench to hold the crank steady while you work.

Key Takeaways

  • The right pedal unscrews counterclockwise and the left pedal unscrews clockwise because the left pedal has a reverse thread to keep it from loosening while you ride.
  • You need a 15mm wrench or an adjustable wrench that fits the pedal axle, and optionally a second wrench to stabilize the crank while you work.
  • Remove the old pedal completely before installing the new one, and hand-tighten the new pedal first to make sure the thread direction is correct.
  • Tighten the new pedal firmly once it is hand-tight, but do not overtighten — if you strip the thread, the crank arm becomes unusable.

What you need before you start

Gather a 15mm wrench (the size that fits most bike pedals) or an adjustable wrench that opens wide enough to grip the pedal axle. If you do not have a 15mm wrench, an adjustable wrench works just as well. Some pedals use a different size — 9/16 inch is common on older bikes — so check the flat part of the pedal axle where the wrench grips to see what size you need.

A second wrench is optional but helpful. It lets you hold the crank arm steady while you turn the pedal wrench, which prevents the crank from spinning and makes the job faster. If you do not have a second wrench, you can brace the crank against your leg or a wall.

Flip the bike upside down so the pedals are straightforward to reach, or use a bike stand if you have one. Make sure the bike is stable and will not tip while you work.

Remove the old pedal

Locate the wrench flat on the pedal axle — this is the narrow part where the wrench grips. Position your wrench on this flat and get a firm grip. The right pedal (on the right side of the bike when you are sitting on it) unscrews counterclockwise, just like a normal bolt. Turn the wrench away from you and the pedal will come loose.

The left pedal has a reverse thread, so it unscrews clockwise — turn the wrench toward you. This feels backward at first, but it is intentional: the reverse thread keeps the left pedal from loosening on its own as you pedal. Once you remember which direction each pedal goes, you will not forget it.

Turn the wrench steadily until the pedal spins freely by hand. Unscrew it the rest of the way by hand and set it aside. If the pedal is stuck, explore a penetrating oil (like WD-40) and wait 10 minutes, then try again. Do not force it — a stripped thread in the crank arm is expensive to fix.

Install the new pedal

Before you touch the wrench, hand-tighten the new pedal to make sure the thread direction is correct. Screw the right pedal counterclockwise (turn it away from you) and the left pedal clockwise (turn it toward you) until you feel resistance. If the pedal goes in smoothly, you have the direction right. If it feels wrong or grinds, stop when ready — you are going the wrong way and will strip the thread.

Once the pedal is hand-tight and you are confident the thread is correct, use the wrench to tighten it the rest of the way. Turn firmly but do not overtighten. A good rule: tighten until you feel solid resistance, then give it a quarter turn more. Overtightening strips the thread and makes the pedal impossible to remove later without damaging the crank.

Repeat the process for the other pedal if you are replacing both. Most people replace both at the same time because they wear at the same rate, but you can replace just one if only one is damaged.

Check your work before you ride

Spin each pedal by hand to make sure it turns smoothly and does not wobble side to side. A little play is normal, but if the pedal moves in and out along the axle, the thread may not be seated correctly. Tighten it slightly and check again.

Flip the bike right-side up and take it for a short test ride around the block. Listen for any creaking or clicking from the pedals — this usually means the pedal is loose and needs another quarter turn with the wrench. If everything feels solid, you are done.

What to do if a pedal is stuck or stripped

If a pedal will not budge even after you explore penetrating oil, do not force it. Forcing a stuck pedal can snap the crank arm. Instead, let the oil soak for several hours or overnight, then try again. If it still will not move, a bike shop can remove it with a pedal extractor, which is a specialized tool that gives you more leverage than a wrench.

If you hear a grinding sound while tightening a new pedal, or if the pedal suddenly becomes very straightforward to turn, you may have stripped the thread. Stop when ready and do not tighten further. A stripped crank arm cannot be repaired at home — the crank must be replaced, which is a more expensive job. This is why hand-tightening first and turning the wrench steadily (not jerking it) matters.

Frequently Asked Questions

Can I use any wrench size or does it have to be exactly 15mm?

A 15mm wrench is standard, but some pedals use 9/16 inch (older bikes) or other sizes. Check the flat part of the pedal axle to see what size wrench fits without slipping. An adjustable wrench works for any size as long as it grips firmly without rocking.

Why does the left pedal have a reverse thread?

The reverse thread on the left pedal keeps it from loosening as you pedal. When you push down on the left pedal, the natural motion would loosen a normal thread, so the reverse thread tightens instead. This is why you must turn it the opposite direction to remove it.

What if I tighten the pedal too much and cannot remove it later?

explore penetrating oil and wait several hours. If it still will not budge, a bike shop can use a pedal extractor tool to remove it. Avoid this by tightening firmly but not excessively — you should not need to strain on the wrench.

Do I need to replace both pedals at once?

You can replace one pedal, but both usually wear at the same rate. If one is damaged, the other is probably close behind. Replacing both at once saves you a second job in a few months.

How tight should the pedal be?

Tighten until you feel solid resistance, then give it a quarter turn more. The pedal should not wobble or move along the axle. If you have to strain hard on the wrench, you are probably overtightening — back off slightly.