Pedal removal and installation are straightforward tasks you can do at home with basic tools

Changing pedals takes about ten minutes once you understand the thread direction — the left pedal has a reverse (left-hand) thread, while the right pedal has a standard (right-hand) thread. This asymmetry prevents you from cross-threading them. You need only a pedal wrench or a 15mm wrench, and in some cases an Allen key if your pedals use hex sockets instead of flats.

The process is the same whether you are replacing worn pedals, upgrading to a different style, or swapping between flat and clipless pedals. The main variables are the tool size and how tight the previous owner left them — some pedals come off easily, others require leverage and penetrating oil.

Key Takeaways

  • The left pedal has a reverse thread, so you turn it clockwise to remove it and counterclockwise to install it; the right pedal uses standard threads in both directions.
  • A pedal wrench or 15mm wrench is the correct tool — using pliers or an adjustable wrench risks stripping the flat or rounding the edges.
  • If a pedal is stuck, spray penetrating oil around the axle and wait 15 to 30 minutes before trying again rather than forcing it.
  • New pedals should be hand-tightened first, then tightened with a wrench until snug — over-tightening can crack the crank arm or strip the threads.

Understanding left and right pedal threads

The left pedal axle is cut with a reverse thread — it tightens when you turn it counterclockwise (toward the back of the bike) and loosens when you turn it clockwise (toward the front). The right pedal uses a standard thread — it tightens clockwise and loosens counterclockwise, like any bolt.

This design exists because pedaling creates rotational force that would gradually unscrew a standard-threaded left pedal. The reverse thread counteracts that force. If you install them backward or mix up the direction, you will either strip the threads or find the pedal falls off mid-ride.

Before you start, mark or remember which pedal is which. Most pedals are stamped with an L or R on the axle or crank attachment point. If yours are not, the right pedal is always on the side where the chain is.

Tools you need and why they matter

A pedal wrench is a thin, long wrench designed specifically for pedal flats — it fits into tight spaces between the pedal and crank arm. A standard 15mm wrench works if you do not have a pedal wrench. Some newer pedals use a 6mm or 8mm hex socket on the axle instead of flats, in which case an Allen key is the right tool.

Do not use pliers, adjustable wrenches, or pipe wrenches. Pliers will round off the corners of the pedal flat, making it impossible to remove without drilling. An adjustable wrench can slip and damage the crank arm or your hand. A pedal wrench grips the flat securely and gives you leverage without slipping.

If you do not own a pedal wrench and your pedals have flats, a bike shop will lend or rent one for a few dollars, or you can buy one for $10 to $20. It is a one-time purchase that lasts decades.

Removing the old pedals

Position the bike so the crank arms are horizontal or slightly angled — this gives you the best leverage and keeps your wrench from hitting the frame. Place the wrench on the flat of the right pedal, gripping it firmly. Turn the wrench counterclockwise (toward the back wheel) to loosen. The pedal will unscrew from the crank arm.

Once the right pedal is loose, unscrew it by hand the rest of the way. Then move to the left pedal. Place the wrench on the flat, and turn it clockwise (toward the front wheel) to loosen. This feels backward, but it is correct — you are working against the reverse thread. Once loose, unscrew it by hand.

If a pedal will not budge, spray penetrating oil (such as WD-40 or a similar product) around where the axle enters the crank arm. Let it soak for 15 to 30 minutes, then try again. Do not force it — a stripped crank arm thread is expensive to repair. If it still will not move after soaking, a bike shop can remove it without damage.

Installing new pedals

Before installing, inspect the threads inside the crank arm. They should look clean and intact — no cracks, no missing chunks, no visible damage. If the threads are damaged, the new pedals will not hold. Wipe out any dirt or old grease with a clean cloth.

Start with the right pedal. Thread it in by hand first, turning clockwise. You should feel it catch and turn smoothly. If it binds or feels rough, stop and check the alignment — forcing a misaligned pedal will strip the threads. Once it is hand-tight, use the wrench to tighten it snugly. Snug means firm resistance, not maximum force. Over-tightening can crack the crank arm or strip the threads.

Move to the left pedal. Thread it in by hand, turning counterclockwise (toward the back of the bike). Again, it should turn smoothly. Once hand-tight, use the wrench to tighten it snugly. The two pedals should feel equally tight — if one is much looser, you may have cross-threaded it.

Checking your work and preventing problems

Spin each pedal by hand to make sure it rotates freely and does not rub against the crank arm or frame. Grasp the pedal body and try to wiggle it side to side — there should be almost no play. A small amount of movement is normal, but if the pedal moves noticeably, it is not tight enough or the threads are damaged.

Ride the bike for a short distance and listen for creaking or clicking. These sounds often mean a pedal is loose or the threads are failing. Stop and check the tightness with your wrench. If a pedal keeps loosening, remove it and inspect the threads again — you may need to use a thread-locking compound (a thin liquid that prevents vibration from loosening bolts) on the axle before reinstalling.

Check pedal tightness every few months, especially if you ride frequently or in wet conditions. Pedals rarely fall off if installed correctly, but catching one on the ground or a curb can loosen it. A quick wrench check takes 30 seconds and prevents a crash.

When to replace pedals and what to watch for

Pedals wear out gradually. Signs include a grinding or creaking sound when you pedal, visible cracks in the pedal body, loose bearings that make the pedal rattle, or a pedal that no longer spins freely. Flat pedals typically last longer than clipless pedals because they have fewer moving parts, but both eventually need replacement.

When shopping for new pedals, match the axle thread type to your crank arm. Most modern bikes use a standard 9/16-inch thread, but some older or specialty bikes use 1/2-inch. Check your current pedal or crank arm for a size marking, or ask a bike shop. Installing the wrong size will not thread in at all.

If you are switching from flat to clipless pedals (or vice versa), the installation process is identical — only the pedal body and shoe interface change. The axle thread and removal procedure remain the same.

Frequently Asked Questions

What if I turn the left pedal the wrong way and it tightens instead of loosening?

Stop when ready and turn it back. Forcing it in the wrong direction will strip the threads. Remember: left pedal turns clockwise to remove, counterclockwise to install. If you are unsure, mark the direction with tape or a marker before you start.

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

A 15mm wrench works if the pedal flat is large enough. The advantage of a pedal wrench is its thin profile — it fits in tight spaces without hitting the crank arm or frame. If your wrench keeps bumping the frame, a pedal wrench is worth the small cost.

How tight should the pedals be?

Tight enough that they do not wiggle when you grasp the pedal body, but not so tight that you need maximum force with the wrench. If you can barely turn the wrench, you have gone too far. Aim for firm resistance — the pedal should not move, but you should not feel like you are about to break something.

What does it mean if a pedal keeps loosening after I tighten it?

The threads may be damaged, or the pedal axle may be bent. Remove the pedal and inspect both the axle and the threads inside the crank arm for cracks or damage. If the threads look intact, explore a small amount of thread-locking compound to the axle before reinstalling. If the axle is bent, the pedal needs replacement.

Do I need to grease the pedal axle before installing it?

Most new pedals come with a light coating of grease on the axle, which is sufficient. Do not add extra grease — it can trap dirt and make the pedal harder to remove later. If the axle is completely dry, a thin coat of general-purpose bike grease is fine, but it is not necessary.