How To Change a Bicycle Chainring: Boost Your Bike’s Performance

Written By: Jonathan
Fact Checked By: Caroline Dezendorf
Reviewed By: Matt Tanner

When you find out that your chainrings is actually worn-out, and which is causing several issues such as poor shifting, chain skipping or even damaging your drivetrain, then you have to actually consider changing it as quickly as possible.

So, basically the chain ring is actually the large toothed ring that is attached to the crankset of your bicycle, which is the part that your pedals are attached to and it really plays a major role in how smoothly or efficiently your bicycle actually runs.

Additionally, most modern bicycles actually use chainrings with 4 or 5 mounting bolts and the exact size and fit depends on something called the bolt circle diameter (BCD), this is a simple measurement that really determines which chain ring is actually suited to your crank.

So, what really happens is that when you ride your chain frequently or don’t maintain it properly, the teeth of the chain wear down and become “bent” or dull, which affects the grip the chain has on the chain ring.

This is why you need to replace it to restore smooth pedaling and better shifting.

And this is the guide that specifically tells you about How To Change a Bicycle Chainring, so you can easily upgrade your chainring and by doing this one thing, you can also increase the life of your chain and cassette.

---

Tools

Tool/Material	Purpose
Allen Keys (Hex Wrenches)	It is used to remove and install chainring bolts which are typically 4mm, 5mm or 6mm in size.
Chainring Bolt Wrench	It’s actually just a matter of needing to put the chainring nut back on while you loosen the bolt but this applies to some crank types.
Crank Puller Tool	It is used to remove square tapers or old crank arms if necessary.
Bottom Bracket Tool	You can use this tool to remove the bottom bracket but it will only be used if the crank requires it.
Torque Wrench (optional)	This is completely optional and up to you, but it ensures that the bolts are tightened to the manufacturer’s specifications, usually 8-12Nm.
Degreaser & Rag	These will be used to clean the crank spider and surrounding area.
New Chainring	The obvious thing is that it must match the bolt pattern (BCD) and number of bolts of your crank.
Bike Stand (optional)	This really makes the process easier by keeping the bike stable at a comfortable height.

---

1. First Prepare the Bicycle

You really need to prepare the bicycle in a proper way to ensure that the process goes more smoothly, safely, and less messy.

1. Shift to the Smallest Chainring and Rear Cog

When you shift your chain to the smallest front chainring and smallest rear cog, which is actually the hardest gear, it reduces chain tension significantly and also gives you better access to the crankset and chainring bolts.

Not only that, but it also reduces the risk of damaging the chain or derailleur when working on the drivetrain.

2. Remove the Chain (If You Find it Really Necessary)

This also really depends on your bicycle and crank style, as you may need to remove the chain to freely access the chain rings, depending on whether your chain actually uses quick links also known as the master link, you can easily disconnect it using a pair of quick link pliers.

Or if your chain doesn’t actually have a quick link: You’ll need a chain breaker tool to take out the pin and take the chain apart.

IMPORTANT: If you are only replacing the outer chain ring and there is sufficient space the chain will not need to be removed.

3. Secure the Bicycle Properly

You really need to make the job easier and keep the bicycle stable, so place your bicycle on a bicycle repair stand.

As it actually lifts the bicycle off the ground it actually holds it in a secure manner, keeping the drivetrain at a comfortable working height as well.

And if you don’t actually have a stand, you can easily and carefully turn the bicycle upside down by placing it on the bicycle seat and handlebars.

Finally, all you have to do is make sure to place a towel or cardboard underneath to protect against any potential scratches.

---

How to Remove the Old Chainring

So, now it’s time to remove the old previously installed chain ring that you wanted to replace.

1. Use the Right Tool to Remove the Bolts

The chain rings are actually held in place by chain ring bolts, which are usually secured by Allen bolts, which can typically be either 4mm or 5mm in size.

Therefore, use a good quality Allen key or chainring bolt wrench, even for bolts with slotted or two-way nuts.

And loosen each bolt evenly, and you can work in a star or cross pattern so you can avoid putting uneven pressure on or twisting the chainring.

If you find that your bolts are really stuck you may need to apply a bit of penetrating oil and give them a few minutes to dry before trying again.

2. Clean the Crank Spider Thoroughly

So, once the chain ring is removed, you will actually see the crank spiders, which are the arms that extend from the crank that support the chain ring.

Simply wipe down the area using a clean cloth and a bicycle-specific degreaser so you can easily remove old grease, grime, and dust.

Because cleaning is so important as debris can build up in there which can really affect how flat the new chain ring sits and can also cause squeaking or premature wear, so it’s best to clean it properly.

Also, you should check for any scratches, cracks, or bending marks on the spider arms, which could actually be a sign of any hidden damage from impact or long-term stress.

3. Check the Bolt Circle Diameter (BCD)

Now, before immediately installing the new chain ring, just make sure it’s fully compatible with your crankset’s bolt layout.

Because it is actually determined by the bolt circle diameter (BCD) which is basically the diameter of the circle that passes through the center of all chainring bolts.

And common BCD sizes include 104 mm, 110 mm, and 130 mm, but many others also exist, so you have to choose it very specifically.

Not only that, you can easily measure the BCD with a caliper, a ruler or you can even check the specifications on the back of the old chainring or the crank manufacturer’s website.

But ultimately, you need to make sure that your new chainring has the same BCD and number of bolts as the old chainring.

NOTE: If there is any kind of mismatch in the BCD or bolt numbers, it literally means the new chain ring will not fit on it, even if the tooth count or brand matches or not it doesn’t really matter.

Also, in practical terms you should replace chain rings every 2 to 3 cassette replacements, as a timely chain change helps prevent premature drivetrain wear later on.[¹]

---

How to Install the New Chainring (Step-By-Step Guide)

Therefore, the most important part of this process is to properly install the new chain ring, because if the chain ring is misaligned, loose or overly tight it can cause any kind of shifting problems, noise or even stripped threads.

Keeping this in mind, this method adopts a careful and precise approach which will surely help you in ensuring long term performance and safety.

1. Align the New Chainring Correctly

First you’ll need to align the new chain ring with the crank spider arms, as most chain rings are actually directional, which simply means their orientation is correct.

So, just look for:

1. Markings such as: “OUTSIDE” or “This side is facing out”, or commonly brand names are also imprinted on the outside.
2. The ramp or pin, sometimes known as the shift pin, can be found near one of the bolt holes, and should be aligned with the back of the crank arm, as it is actually designed to help lift the chain during shifting.
3. On single speed or narrow-wide chainrings that are used in a 1x setup, the tooth pattern should be consistent and the orientation alternate which may not be marked, but you should check the manufacturer’s guide if you’re really unsure about it.

So, basically you have to get it aligned properly because it really makes sure that the chain ring engages smoothly with the chain and also shifts cleanly, and you specially have to make sure on a multi-chain ring setup.

2. Insert and Tighten the Bolts Evenly

Now, you must insert the chainring bolt by hand first so that you can avoid cross-threading as well.

And then use an Allen key or chainring bolt wrench to tighten the bolts in a star or cross pattern just like the nuts on a car wheel.

This pattern really helps to distribute the pressure evenly and that is why it prevents the chain ring from bending in any way or sitting unevenly against the crank spider.

Moreover, you have to gradually tighten each bolt in the opposite direction to each other until all the bolts are properly tightened.

IMPORTANT: If you discover that the old chainring bolts are worn out or completely stripped, simply use new chainring bolts.

3. Use the Grease or Loctite

Yes, some manufacturers actually recommend applying a small amount of grease to the threads of bolts as this prevents problems with stiffness, rust or squeaking.

And others suggest using a medium-strength thread locker, such as Loctite Blue 242, to prevent the bolts from loosening over time by protecting them from vibration.

So, basically grease helps with future removal and is commonly used in steel and aluminum bolts, and Loctite is often preferred in high-vibration environments such as mountain bicycles.

That’s why you should always check your chainring or crank manufacturer’s recommendation, if one is available.

4. Use a Torque Wrench to Tighten It Precisely

So, once the bolts are in the right place, you will now need to use a torque wrench so that you can safely tighten them to the correct specification.

Also, most chainring bolts actually require torque between 8 and 12 newton-meters (Nm): so just check your specific crank or chainring instructions to find the exact value.

Also, when you use a torque wrench it definitely helps you avoid over-tightening it, as that can literally strip the threads or crank the chainring, it also prevents under-tightening which can actually loosen the bolt while riding.

IMPORTANT: If you don’t actually have a torque wrench just tighten it firmly, but don’t over tighten, basically avoid “gorilla-tightening” the bolts.

Read More:

How To Remove Bicycle Axle

How To Shorten a Bicycle Chain

---

Conclusion On How To Change a Bicycle Chainring

This is a proper guide that shows all the complex operations in a simple way, so that you can easily change your bicycle chainring.

So, the reason for replacing bicycle chainring can be anything like you want to upgrade your gear ratio for better climbing or speed or you actually want to replace a worn out ring etc.

But you have to make sure that the torque on the bolts should be proper and you also have to check the chain alignment so that you can make your journey smoother, more efficient and safer.

Do you want to ask questions, the comment section is welcoming you for that.

---

Frequently Asked Questions

---

References:

[1] Bike Forums. Chainring replacement frequency – every 2–3 cassette changes.
https://www.bikeforums.net/road-cycling/1159845-chainring-replacement-frequency.html