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Bike Chain Replacement And Maintenance

Matt Donovan,	3rd generation Owner and General Manager of Dedham Bike

By: Matt Donovan,
3rd generation Owner and General Manager of Dedham Bike
Last updated: 1/8/25

It’s best to replace your bike chain often to save money!


Even with regular maintenance & lubrication most bicycle chains need to replaced about every 1500 miles, however mountain bikes need bike chain replacement more often due to mud, dirt and other debris speeding up wear.  At this point a chain has been stretched and worn to a point where it causes severe damage to the chainrings, cassette or freewheel and pulley wheels of the rear derailleur. All this extra wear and tear can cause you hundreds of dollars in necessary repairs. The good news is there's a simple step you can take to help to keep this from happening!



" how to measure a bike chain"

Chain wear & chain stretch

As you accumulate miles on your bike’s drivetrain components (chain, crank, cassette, derailleurs) your chain begins to stretch & weaken. When you ride you are not only stretching the chain lengthwise but you are also flexing and wearing the chain’s side plates. This weakens the chain’s ability to shift as sharply as it once did as well as increases wear to your cassette, chainrings and derailleur pulley wheels. We have to remember that a bike’s drivetrain is made up of metal and this metal breaks down and wears with increased mileage. A worn chain increases the amount of wear and tear on the other parts of the drivetrain. All the pieces of your drivetrain are meant to smoothly mesh together, once too much wear sets in it becomes much harder to impossible for this synergy to happen. By replacing your chain more frequently you are maximizing the life of the drivetrain of your bike, saving you a bunch of money over time. Are you seeing why more frequent bike chain replacement is a good thing?

How do you know if your chain is worn?

One telltale sign of a worn-out chain is reduced performance in shifting and perhaps an increase in noise. If your chain skips under load (sprinting or climbing), then it’s definitely replacement time! A skipping chain can also result in an injury, so get it replaced ASAP.

How to Measure Bike Chain Wear

There are 2-3 simple ways to see if your chain is worn or stretched. The most technical and best way is to use a chain measure tool. We suggest using a chain measuring tool like the Park Tool CC-3.2. It’s very easy to use and inexpensive.

Using a Chain Wear Tool

  1. Positioning the Tool: Hook one end of the tool over a roller (or pin) in your chain.
  2. Checking the Fit: Observe where the other end of the tool rests. It will either sit on top of the chain or drop between the rollers.
  3. Interpreting the Reading:
    • If it drops between the rollers, it indicates your chain is stretched and should be replaced.
    • Tool Readings:
      • A reading of 0.5 to 0.75 suggests you should replace your chain.
      • A reading of 0.75 or higher means you not only need to replace your chain, but you should also check the condition of your cassette and chainrings for excessive wear.

By understanding these steps, you can accurately gauge your chain's wear and prevent further damage to your bike components.

How to Check a Bike Chain for Excessive Stretch Using a Ruler or Tape Measure

Maintaining your bike chain is crucial for peak performance and longevity. One effective way to inspect your bike chain for excessive stretch is by using a simple ruler or tape measure. Follow these steps to accurately assess your chain:

  1. Prepare Your Tools:

    • Grab a standard ruler or a reliable tape measure. Ensure it has clear, precise markings for accuracy.
  2. Position Your Chain:

    • Make sure your bike is stable, either by using a bike stand or flipping the bike upside down. This will give you easy access to the chain.
  3. Measure 12 Full Links:

    • Locate one link on your chain, and count exactly 12 links from it. Each link is defined from one pin to the next pin.
    • Align the 0 mark of your ruler at the center of your starting pin.
  4. Check the Length:

    • Once you've aligned the ruler or tape measure with the starting pin, check where the ruler meets the 12th pin.
    • On a new, unstretched chain, the length should measure precisely 12 inches.
  5. Interpret the Results:

    • Exact 12 Inches: If the measurement is exactly 12 inches, your chain is in good condition and doesn’t require replacement.
    • Over 12 Inches: If the measurement is 12 1/8 inches or longer, it's a clear indication your chain has excess stretch. At this point, you should replace your chain to prevent additional wear and tear on other components like the cassette and chainrings.

By regularly performing this simple check, you can ensure a smoother ride and prolong the lifespan of your bike's drivetrain components.

How much does a bike chain cost to replace?


Entry level chains can start off around $15.00 with more expensive and higher performance chains ranging from $25.00 to $60.00 or more. More expensive chains increase shift quality and are generally more durable as they wear. A more expensive chain may be a few grams lighter as well if weight is a concern for you. Most shops charge $20 to $30 to install a chain or you can purchase a chain tool for $10 to $50 and learn to do it yourself. Having a chain tool in your tool box is never a bad idea in any case.

How to Determine the Correct Length for a New Bike Chain

When you get a new bike chain, you'll often find it's too long for your specific drivetrain. Adjusting it to the right length is crucial for optimal performance. Here's how you can do it:

1. Compare with the Old Chain

  • Lay Them Side by Side: One of the simplest methods involves placing the new chain alongside the old one.
  • Match the Links: Count the links on your old chain and match the new chain to this length. This method depends on having the correct old chain as a reference.

2. The Big-Big Method

  • Position the Chain: Thread the new chain through the front derailleur and drape it over the largest front chainring and largest rear cog.
  • Avoid Rear Derailleur: The chain should not pass through the rear derailleur at this stage.
  • Find the Overlap: Pull the chain ends together until they meet. The correct length will have the chain ends touching with an overlap of two additional links (approximately one inch).

3. Consider Suspension

  • Chain Growth: If you have a full-suspension mountain bike, remember that suspension movement (known as "chain growth") can affect chain length.
  • Compress the Suspension: Fully compress the rear suspension while measuring to account for extra chain length needs.

4. Finalize the Length

  • Correct Connection: Before cutting, ensure you can connect the outer plate of one chain link to the inner plate of another.
  • Use a Chain Tool: Remove any excess links with a quality chain tool, ensuring a clean cut.

By following these steps, you ensure that your new chain is perfectly sized for your bike, providing smooth gear shifts and preventing any potential drivetrain damage.

How to Repair a Bike Chain: A Step-by-Step Guide

Maintaining a smooth ride requires a well-functioning bike chain, which is responsible for transferring power from the pedals to the wheels. A slipped or broken chain can be a common issue for cyclists, but with the right knowledge, it can be an easy fix. Understanding how to repair a bike chain will not only save a trip to the bike shop but also keep a ride going without major hitches.

Having the proper tools at hand, such as a chain breaker tool, and knowing how to use them is essential for repairing a bike chain. Repairing your bike chain involves examining it for damage such as bent links, which can cause further issues if not addressed. Knowing the signs of a worn chain, such as difficulty in shifting gears or a sagging chain, can help in determining whether a repair or a full replacement is necessary. Frequent inspections and timely repairs can extend the life of a bike chain and improve cycling performance.

Installing a bike chain might seem daunting, but with the right approach, it's straightforward. Here's how you can do it using either a chain pin or a master link:

Step-by-Step Guide to Installing a Bike Chain

Threading the Chain

First, ensure the chain is properly threaded through the bicycle’s rear derailleur. Pay close attention when routing it through the derailleur's pulley wheels to avoid any misalignment.

Using a Chain Pin

  1. Determine the Need: If your chain lacks a master link, you'll need a chain pin. This tool is used for reconnecting chains.

  2. New vs. Existing Chain: For new chains, use the pin provided with your purchase. If repairing, always opt for a new pin rather than reusing an old one to ensure reliability.

  3. Insertion Process:

    • Place the chain ends together and use a chain tool to guide the pin through the links.
    • Push the pin midway through to hold the links together.
    • Using pliers, snap off any extra length protruding from the pin.

Using a Master Link

  1. Preparation: Separate the master link into two pieces and attach one piece to each end of the chain.

  2. Joining the Ends:

    • Pull the chain ends together.
    • Align and assemble the master link pieces, ensuring they're properly fitted.
  3. Securing the Link:

    • Use a master link tool to lock the link securely, or attempt without it by:
      • Pulling the chain sides apart to lock the link as firmly as possible.
      • Releasing the derailleur clutch, if available.
      • Positioning the master link on top of the drivetrain.
      • Engaging your brakes and applying downward force on the pedal to tighten and click the link into place.

By following these steps, you'll have your bike chain installed efficiently, whether using a chain pin or master link. Enjoy your ride!

Steps to Remove a Bike Chain

Removing a bike chain can seem daunting, but with the right approach, it’s straightforward. Here’s a guide for removing a chain with and without a master link.

Preparing to Remove the Chain

  1. Shift Gears: Begin by shifting your bike into the smallest chainring and cog. This step is crucial for reducing tension on the chain.
  2. Optional Step: For even easier access, consider removing the chain from the front chainring or detach the rear wheel.

Removing a Chain Without a Master Link

  1. Position the Chain Tool: Place the chain in a chain tool, aligning the tool's pin with one of the chain pins.
  2. Push the Pin: Turn the tool's handle to push the pin out of the chain link. Be careful not to remove the pin completely to make reassembly easier.

Removing a Chain With a Master Link

  1. Identify the Master Link: Look for a link that appears different from the others when viewed from the side—this is your master link.
  2. Use Master Link Pliers: Insert the jaws of the master link pliers around the pins of the master link. Squeeze the pliers to compress the pins toward each other.
  3. Release the Link: Once the link is compressed, it should pop open, allowing you to separate the chain.

By following these steps, you'll have your bike chain removed in no time, ready for maintenance or replacement.

What Should You Consider When Shortening a New Bike Chain?

When fitting a new bike chain, obtaining the correct length is crucial for optimal performance. Here's a guide to ensure your chain is perfectly sized:

Determining the Correct Chain Length

  1. Comparison Method:
    Lay the new chain alongside the old chain on a flat surface. Align them to ensure accurate comparison and adjust the new chain to match the length of the old one. It's a good idea to double-check by counting the links to confirm consistency.

  2. The Big-Big Method:

    • First, thread the new chain through the front derailleur.
    • Drape it over the largest chainring in front and the biggest cog at the back.
    • Without routing it through the rear derailleur, bring the ends together and pull them taut.
    • The correct length is where the chain ends meet, plus an additional inch or two full chain links for overlap. This allows for connection with the extra half-link you'll remove last.

Special Considerations for Mountain Bikes

If you own a full-suspension mountain bike, be aware of the concept known as "chain growth." This occurs when the rear axle moves away from the bottom bracket as the suspension compresses. To account for this, compress the rear suspension fully when measuring your chain length using the method above.

Tips for Removing Links

  • Ensure compatibility by checking that the chain ends you intend to connect consist of an outer plate and an inner plate, as only these can effectively join.
  • Use a reliable chain tool to safely remove the unnecessary links.

By following these guidelines, you'll ensure your bike chain is not only securely fitted but also performs efficiently across all terrains.

Key Takeaways

  • Routine inspections are crucial for bike chain maintenance.
  • Having the correct tools enables efficient chain repairs.
  • Timely repairs or replacement prevent cycling disruptions.

Frequently Asked Questions

In this section, you'll find clear answers to common queries on how to address varying issues involving bike chains, from fixes without tools to assessing whether to repair or replace a chain.

Can you fix a broken bike chain without a tool?

While it's challenging to fix a broken bike chain without the right tools, it's sometimes possible to make a temporary fix by manually reattaching the links. This method is not recommended as it's unreliable and may damage the chain further.

What are the necessary tools for replacing a bike chain?

The essential tools for replacing a bike chain include a chain breaker tool, a pair of pliers, and a replacement chain that matches your bike's gearing system. 

Additional Tools and Parts for Comprehensive Chain Maintenance

  • Chain Wear Tool: This is indispensable for assessing the condition of your chain. It hooks over one roller while the other end inserts between two rollers, indicating how worn the chain is. This tool helps you decide if it's time for a replacement.

  • New Chain: When purchasing a new chain, ensure it matches your bike's speed. For example, a 9-speed bike requires a 9-speed chain. Some high-end options come with rust-resistant coatings or stainless steel construction.

  • Replacement Pin or Master Link: New chains often include a pin or a master link for connecting the chain ends. If you're repairing an existing chain, these can be bought separately, ensuring compatibility with your chain's speed and brand.

  • Chain Tool: Necessary for removing old pins and inserting new ones, a chain tool is vital for breaking and reconnecting chains with standard links.

  • Master Link Pliers: If your chain uses a master link, these pliers make disconnecting and reconnecting the link much easier, enhancing the maintenance process.

By equipping yourself with these tools and parts, you can effectively maintain and repair your bike chain, ensuring a smooth and efficient ride.

What is the method for reattaching a bike chain to a derailleur?

To reattach a bike chain to a derailleur, shift your gears to the smallest cog, thread the chain through the derailleurs correctly, and use a master link or a chain tool to reconnect the ends. Ensure the chain runs smoothly over the pulleys and gears.

How do you handle a bike chain that's come off the gears?

When a bike chain has come off the gears, carefully lift the chain and place it back onto the chainring. To prevent injury or further derailments, rotate the pedals backwards while guiding the chain onto the smallest cog before shifting it to the desired gear.

Is it better to repair or replace a damaged bicycle chain?

Whether to repair or replace a damaged bike chain depends on the extent of the damage. If the chain is excessively worn or damaged, replacement is often the better option, as revealed by tools designed to measure chain wear, such as those mentioned in Beginner’s Guide on How to Replace a Bike Chain or Fix It.

What steps should be taken if a bike chain is stuck or jammed?

If a bike chain is stuck or jammed, first assess if there's a blockage or bent link. Then carefully work the chain free, avoiding force that might cause damage. Use appropriate tools to gently remove any obstruction and to straighten or replace bent links.

How long do bike chains last?

This is a very good question and the answer changes depending on the usage of the bike. 

For example, a road bike that is ridden primarily on pavement and in a cleaner environment can see upwards of 1500 miles out of a chain before it starts to wear significantly. 

On the flip side, that same bike ridden in a dirty environment such as dirt roads and gravel riding will see wear at a lower mileage due to the increase wear caused by mud and grime that will cause the chain to break down more quickly.

Mountain bikers can expect to go through chains more quickly, especially in muddy or sandy environments as the mud and sand will act like sandpaper on your drivetrain causing damage that will speed up the end of your chain.

With all this in mind, proper bike maintenance with add life to your cassette and chain so you can spend more time in the saddle and less time in the repair stand.

What if you wait too long to replace your chain?

If you wait to replace your chain until you start skipping under load or start snapping your chain, then you're likely facing more than just a chain replacement. You'll probably need to replace your cassette too. The chain and cassette are meant to work in harmony; the chain is designed to sit smoothly on the teeth of the cassette. When the cassette becomes too worn, it can't hold the chain any longer because its teeth are too worn down.

Another downside to waiting too long is that your front chainrings can become "shark toothed," meaning they can't hold a chain properly due to excessive wear and tear. An easy way to determine this is if you're able to see daylight between the chain and the teeth of the big chainring when looking at the bike from the geared side.

The cost to replace a cassette or freewheel can range anywhere from $25 to upwards of $300 on high-end bikes, and chainrings can run anywhere from around $40 to $250 on high-end bikes. So, replacing your chain often makes even more sense when considering these costs—and these prices don't include labor costs either!

What are some specific maintenance tasks related to bike chains?

Maintenance tasks include changing the bike cassette, replacing bike chainrings, cleaning the bike chain, and performing basic bike maintenance.

Related Maintenance Tasks To Be Done As Needed

Maintaining your bike chain is just one part of keeping your bike in top condition. Here are some related tasks that can help prolong the life of your drivetrain:

  • Change Your Bike's Cassette: Essential when your cassette's teeth become too worn out.
  • Change Your Bike's Chainrings: Necessary if your chainrings show signs of damage or excessive wear.
  • Bike Chain Cleaning and Maintenance: Regular cleaning to prevent buildup that can cause wear.
  • Basic Bike Maintenance: Comprehensive care to ensure your bike runs smoothly and efficiently.

By keeping up with these related tasks, you can avoid costly repairs and ensure that each part of your bike works in harmony.

What about chain maintenance?


Simply put, you need to give your chain some love. Just by lubricating and cleaning your chain often you will increase it’s lifespan.

An easy way to do this is to pick out a chain lube that works for you (your bike shop can help you here) and apply the lubricant to your chain every 2-3 rides. You don’t want to over lubricate and you should only use bicycle friendly lubricants, no motor oil here folks & no old school WD-40 (it strips lubricants away) either!


Apply the lubricant to the chain by turning the cranks as you apply the lube liberally, once done continue to turn the cranks a few rotations to allow the lube to sink into the chain. At this point you’ll want to take a clean rag and wipe the excess chain lube off as well as any debris and dirt that has loosened up from the new lubricant. You’ll want to continue to do this until your rag is getting minimal dirt and grime on it, in the real world you’ll never really get it all but do your best. So not only are you lubing the chain but you’re cleaning it too, this is a win-win!


If your chain is excessively dirty you may want to apply a citrus based degreaser to help loosen up the heavy stuff before applying your lube. We suggest using a good chain degreaser and cleaner as it works well and is generally non-toxic. You’ll follow the same steps as applying your chain lube to get the best results, just wait a couple of minutes before wiping your degreaser off to allow it to work it’s magic! If you decide to use a degreaser make sure you apply your lubricant after you’re done cleaning as a chain with no lube will wear out quicker, taking your drivetrain with it.

In conclusion


Now that we’ve gone over when to replace your bike chain and why you should as well as some basic chain maintenance you should be on your way to having a fresher, better working drivetrain!


If you need more help or have any questions please contact us and of course we’re here to help with chain replacement and any other service needs you may have. 

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