I always need help to loosen up my pedals during bike maintenance. I try using the tools available in my garage during bike maintenance. Still, none can provide the force to release my pedals from the crank threads. So, I bought a pedal wrench hoping it would do the trick. 

In this article, I will share my pedal maintenance experience using my pedal spanner. This article will also discuss the wrench size you need for your pedals and some maintenance tips to make the job easier.

Bike pedals do not necessarily require a pedal wrench; an open-ended wrench often suffices. However, a dedicated pedal wrench provides better leverage and fits pedals more effectively due to its thinner width and slight offset. (Hitting your knuckles on the chainring really hurts)

What’s Special About Pedal Wrenches?

Pedal wrenches are thinner than open end wrenches
Pedal wrenches are thinner than open end wrenches

One of the most challenging parts of at-home bike maintenance is adjusting the pedals’ threads from the bike’s crank arms. The crank arms hold the bike pedals tightly, making it impossible to break them loose with your bare hands. Fortunately, there are available tools that can make this job more manageable.

A pedal wrench or pedal spanner is a thinner variation of the standard open-ended wrench. The thin body of the pedal spanner allows it to fit the narrow gripping surfaces of the pedals.

What makes it so special if a pedal spanner is similar to an open-ended wrench?

The answer is the amount of grasp it provides to people who repair and maintain their bikes at home. A pedal spanner has a long body, allowing at-home repairers to hold it at an angle while applying a lot of force. This way, removing the pedals from the crank arms will be much easier, as the pedal spanner will help you apply the pressure needed. (source)

What Size Wrench For Bike Pedals?

Adjusting, removing, and installing bike pedals are possible using a standard open-ended or combination wrench. However, having the correct pedal wrench size makes the task faster and easier. A high-quality pedal spanner should provide the help you need while staying durable despite repeated force application.

The majority of modern bikes have pedals that require a 15-millimeter spanner. Some bike pedals require a 17-millimeter spanner, but they are rare in most of today’s bikes. That said, there is an excellent chance that the bike you have at home needs a 15-millimeter pedal spanner.

However, it is still better to measure your pedals before purchasing a spanner. This way, you can ensure you get the correct tool. If you need an idea of measuring your pedal’s crank thread, you can ask a local bike shop for help during your purchase.

Moreover, some pedals require a 9/16-inch pedal wrench. This size is usually seen on old bike models and is uncommon on modern bike pedals. (source)

MTB Tools I Love and Recommend

Bike Hand Repair Stand
Bike Hand Repair Stand
Bike Hand 37 pcs Tool Box
Bike Hand 37 pcs Tool Box
Topeak Smartgauge D2 Air Pressure
Topeak Smartgauge D2 Air Pressure

I own each of these tools and only recommend things I own and use.

  • Bike Hand Bike Repair Stand.  Nice mountain bikes don’t have a kick stand so keeping your MTB safe but conveniently stored is essential.  I keep my bike on my stand whenever I’m not riding it.  This makes it easy to lube the chain, inflate the tires and adjust the derailleur.  Highly recommended – Bike Hand Bike Repair Stand (👈 Link to Amazon to see what thousands of others have said)
  • A basic MTB toolbox for replacing a chain, adjusting brakes and dialing in the fit.  Bike Hand has a 37-piece box that has most of the specialty bike tools to keep your MTB properly maintained.  The Bike Hand brand is value packed for the avid rider.  Check out the competitive prices with this link to Amazon 👉 Bike Hand 37 pcs Bike Repair Tool Kit
  • Get a good air pressure gauge, if you get just a tiny bit serious about MTBing you’re going to start playing with tire pressure.  A couple psi can make your tires sticking or not.  Get a good gauge, I highly recommend the Topeak Smartgauge D2, it’s accurate, flexible and easy to use.  An Amazon best seller, here’s a link 👉 Topeak Smartgauge D2
  • Carry a multitool with you on every ride.  I’m serious, most of the time you can MacGyver something to get back to the trailhead if you have a multitool.  I’ve got the Crank Brothers M19, it’s worn, rubbed and abused – but it still works.   Thousands sold on Amazon – check it out with this link 👉 Crank Brothers M19

Which Direction To Remove Pedals

The right and left sides of the pedal threads are different. For this reason, the direction you need to twist them during pedal removal also differs.

When removing your bike’s pedals, you need to twist the right-hand thread counterclockwise to remove it. On the other hand, turning the left-hand thread clockwise loosens and removes it.

Remembering the direction where you need to twist when removing the pedals can be confusing. So, you can look at where the pedal threads are sloping to find its loosening direction. The left-hand pedal thread slopes up to the left, while the right-hand pedal thread slopes up to the right. That said, you need to twist towards the opposite direction of the slope when removing your pedals. (source)

How Tight Should You Tighten Bike Pedals

A bike’s pedals should be tight to stay upright during rough rides. Bike pedal threads tend to loosen during rides, especially if they need to be tight enough from the start. It is also why bikers check their pedals from time to time when cycling.

Moreover, your bike pedals must be firm and snug but not to the point that your pedal wrench can no longer remove them. Trek Bikes, one of the leading bicycle manufacturing companies today, recommends that bike pedals should have a torque value of 40 to 43 Nm (Newton-meter). This torque value gives your pedals enough firmness to prevent them from coming loose during a ride.

Following a torque value of 40 to 43 Nm when adjusting your pedals will also prevent you from damaging them. Over-tightening your pedals can deform and break their threads, so following the recommended torque value is essential. (source)

Do You Need A Torque Wrench When Tightening Bike Pedals?

Unless you know how to adjust a bike pedal to its correct torque value or a professional bike mechanic, you need to use a torque wrench when tightening your pedals. If you guess the force measurement you will apply to the pedals, you will either under or over-tighten it. Both issues can lead to damage, so using a torque wrench to measure the pressure you apply to your bike pedals is crucial.

Moreover, it is ideal to refer to your bike’s manufacturer specifications for the torque value your pedals need. While 40 to 43 Nm is a standard, some bike pedals require a different torque value depending on their manufacturers. (source)

Looking for Some More Ways to Help Your Bike Last

How To Remove Rusty Pedals

Rust makes it challenging to loosen up and remove the pedals. If your bike pedals have corroded threads, the rust around them becomes a difficult-to-remove bond. This bond can be difficult to break, even if you apply a lot of force to loosen the pedals from the threads. Your pedal wrench comes in handy when stuck pedals are an issue.

Breaking the rust’s bond

The first step to removing your bike’s rusty pedals is to apply penetrating oil all over the threads. The oil will break the bond between the threads and the pedals caused by the rust. Make sure to apply penetrating oil generously and let it sit for a few minutes. The rusty the pedals are, the longer you need to soak them in oil.

Use your pedal wrench to loosen up the threads.

You can use a regular 15-millimeter spanner to remove the pedals. But if your rust problem is severe, you may need more leverage than a standard open-ended spanner can provide. Applying force to remove the pedals is also easier if you have a pedal spanner.

Tap the spanner with a heavy material

If your pedals would not budge, no matter how much pressure you apply in twisting them, you can use a heavy object to get more leverage. Use whatever item you have to push your pedal spanner in the direction of the turn. However, ensure not to strike the spanner too forcefully, as it could lead to damage.

After the removal process and your rusty pedals are still stuck, the best thing to do is to bring it to a professional mechanic. These people are knowledgeable about bike repair and maintenance. So you can ensure that they have a solution for your rusty pedals. (source)

Hex Key And Allen Wrenches For Bike Pedals

Some bike pedals require a hex key or an Allen wrench instead of a pedal wrench. A hex key is a handheld bike tool that you can use to adjust hexagonal screws.

If bolts and screws with hexagonal sockets are holding your bike pedals in place, you need an 8-millimeter hex key or Allen wrench to adjust or remove them. Some pedals require a 6-millimeter hex key, but they are very uncommon.

Remove pedals from MTB
Remove pedals from MTB

Unlike a pedal wrench that grasps the bike pedals’ threads, a hex key has to fit the screws’ socket. Once the screw’s socket holds the end of the hex key firmly, you can pull the other end toward the direction that loosens the pedals.

A hex key with a long handle is ideal for bike pedal adjustment. The long handle will give you enough room for grip, allowing you to apply the pressure needed to adjust the pedals.

Moreover, you can purchase a set of hex keys for your bike online. The bike’s pedals will only require either the 6-millimeter or 8-millimeter key. However, you can use the remaining sizes for other bike adjustments. (source)

Keep Pushing Those Pedals

A pedal wrench is not a tool required for every home bike mechanic to have. However, it is very convenient, as it can make bike pedal adjustment easier.

Modern bikes usually require a 15-millimeter pedal spanner for pedal adjustment. You may also encounter bikes that use a 17-millimeter pedal spanner, while old bike models require a 9/16-inch spanner.

Furthermore, bike pedals need to be adjustable using a pedal spanner. Instead, it would be best to have a hex key or an Allen wrench to tighten and remove them. Bikes’ standard hex key size is 8 millimeters, but some use a 6-millimeter hex key.


David Humphries is the creator of DIY Mountain Bike. For me a relaxing day involves riding my mountain bike to decompress after a long day. When not on my bike I can be found wrenching on it or making YouTube videos at 👉 DIY Mountain Bike Read more about David HERE.


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