Conquer the Road Again: A Comprehensive Guide to Fixing a Broken Bicycle Chain

There’s nothing quite like the frustration of a broken bicycle chain. One minute you’re smoothly cruising along, enjoying the breeze, and the next, you’re stranded, facing a mangled mess of metal. But don’t despair! A broken chain, while inconvenient, is a repair most cyclists can handle with a little know-how and the right tools. This comprehensive guide will walk you through the steps to fix a broken bicycle chain, get you back in the saddle, and empower you to handle similar situations in the future.

Why Chains Break: Understanding the Culprits

Before diving into the repair process, it’s helpful to understand why bicycle chains break in the first place. Here are some common culprits:

• Wear and Tear: Like any mechanical component, bicycle chains wear down over time. Constant friction and stretching eventually weaken the metal, making it susceptible to breakage. Regularly inspecting your chain for wear is crucial.
• Improper Shifting: Shifting gears under heavy load, especially on hills, can put excessive stress on the chain, leading to damage or breakage. Smooth and intentional shifting is key.
• Poor Maintenance: Neglecting regular chain lubrication can increase friction, accelerate wear, and make the chain more prone to failure. A well-lubricated chain is a happy chain.
• Obstructions: Sometimes, debris like rocks or twigs can get lodged in the drivetrain, causing the chain to bind and potentially break.
• Manufacturing Defects: Though less common, a flawed chain link from the manufacturer can be the cause of breakage.
• Bent Derailleur: A bent derailleur hanger can cause a misalignment in the chain leading to stress and eventual breakage.

Tools You’ll Need: Gearing Up for the Repair

To fix a broken bicycle chain, you’ll need a few essential tools. Having these items readily available will make the repair process much smoother:

• Chain Tool (Chain Breaker): This is the most critical tool. A chain tool is used to push out the pins that connect the chain links, allowing you to separate the broken section and rejoin the chain. You can purchase a basic one for under 20$.
• Replacement Master Link (Quick Link): Many modern bicycle chains use a master link (also called a quick link) to connect the chain ends. This small link is easily installed and removed with your fingers or with pliers. Keep a few on hand to save yourself some time on the road. The correct quick link must be compatible with the speed of your chain (e.g. 8 speed, 10 speed etc).
• Pliers (Optional): Pliers can be helpful for manipulating the chain and closing a quick link if it’s tough to close with your fingers alone.
• Disposable Gloves (Optional): Bicycle chains are notoriously dirty. Gloves can help keep your hands clean during the repair.
• Rag or Shop Towel: For wiping off dirt and grease from the chain and your tools.
• Chain Lube: Once you’ve repaired the chain, you’ll want to re-lubricate it to ensure smooth operation and prevent future issues.
• Multitool (Optional, but recommended): Having a multi-tool with Allen wrenches can be helpful in case you need to adjust anything along the way.

It’s wise to assemble these tools into a small repair kit to carry with you on your rides, especially longer ones. This way, you’ll be prepared for any unexpected chain troubles.

Step-by-Step Guide: Repairing Your Broken Chain

Now that you have your tools ready, let’s get into the actual repair process. These instructions assume your chain broke and can be rejoined either with an existing quick link or using a new one. If you have other types of damage, you may need to consider getting a new chain.

Step 1: Assess the Damage and Prepare the Chain

• Identify the Break: Carefully examine the chain to pinpoint where it broke. Usually, you’ll find a link that is twisted, broken, or separated.
• Remove the Broken Section: If you have a broken section of chain, and not simply a link that came apart, you will have to remove any broken pieces of link. This will likely require using the chain tool to push out pins.
• Clean the Area: If possible, wipe away any dirt or debris around the damaged area to get a clearer view and prevent contamination during reassembly.
• Position the Chain: Place the chain so you can work on the broken link or chain end. You might need to rest the chain over a chain stay or on the ground so you can get the appropriate leverage with your chain tool.

Step 2: Using the Chain Tool to Remove a Pin (if required)

• Open the Chain Tool: Turn the handle on your chain tool to open up the pin pushing mechanism.
• Position the Chain in the Tool: Position your chain inside the tool so the pin you want to remove is centered with the pin driver on the chain tool. Make sure you position the pin directly over the opening where the tool will push out the pin.
• Push out the Pin: Start slowly turning the handle of the chain tool clockwise. The driver of the tool should start pushing out the pin of the chain. Don’t push the pin all the way out. Push it just far enough so you can separate the chain link. Once the chain is separated, you can back out the driver on the chain tool. If you do push it all the way out, you will need to reinsert the pin by placing the chain in the tool in the reverse position and driving the pin back through.
• Separate the Chain: If you have a broken section, you may have to repeat this process to separate the full broken segment. Make sure you do not lose any of the chain parts in the process.

Step 3: Prepare to Rejoin the Chain with a Master Link

• Inspect Chain Ends: Make sure both ends of the chain you intend to rejoin are compatible with your quick link. You should have one end that has two side plates and the other end should have the pin ends protruding.

Step 4: Connect the Master Link

• Insert the Quick Link: Insert one side of the quick link into one end of the chain, and then the other half of the quick link into the other side of the chain.
• Close the Link: The quick link will now be resting loosely with both halves in each side of the chain. The side plates of the master link must be engaged so that the link does not come apart. There are various methods to do this, the simplest is with the tool-less type that slides together. If you have a tool-less type link, simply pull both chain ends together, which should engage the link. If this method does not work, you will have to use pliers. Position the master link so that one side of the link can be gripped with the pliers. Grip the other side with your other hand and use the pliers to pull the link together so that the sides engage.
• Verify Proper Closure: Ensure the master link is fully engaged and secure. There should not be any side play with the master link.

Step 5: Test the Repair

• Rotate the Pedals: Slowly turn the pedals forward to rotate the chain and verify the newly joined link moves smoothly through the derailleur and across your cassette.
• Listen for Unusual Sounds: Pay attention to any clicking, grinding, or stiffness in the chain as it rotates. Any of those sounds would indicate a problem with the repair.
• Check for Alignment: Make sure the chain is running smoothly and is not being forced or angled in any way, which may cause further problems.
• Re-lubricate the Chain: Once you’ve successfully reattached the chain, apply a drop of chain lube to each link to ensure smooth operation and prevent rust and wear.

Troubleshooting Common Issues

Sometimes, even with the best intentions, things might not go perfectly. Here are some common issues you might encounter and how to troubleshoot them:

• Chain Link is Still Stiff: If the newly joined link feels stiff, it may be that the quick link is not fully engaged. Try gripping both ends of the master link and engaging it firmly. If the link still does not move well, there is a chance that you did not correctly engage the link. Remove the quick link and re-install.
• Chain Keeps Breaking: If your chain keeps breaking in the same place, there could be an underlying issue like worn chain or cassette. You might consider replacing your drivetrain parts. If the chain is breaking in different places, inspect your derailleur hanger to see if it is bent or otherwise damaged which may cause the chain to misalign and break.
• Can’t Open the Chain Link with the Tool: If you have a chain tool with a removable driver, you may find that your chain tool is not powerful enough to push out some hardened pins. In those cases, it might be worth considering a higher quality chain tool. If the chain tool is getting stuck while pushing out a pin, try lubricating the chain tool.
• Lost the Pin: If you remove the pin from a chain, you will often find that the pin is nearly impossible to reinsert. In that case, it is best to use a quick link.
• Quick Link is Too Difficult to Close: Some quick links can be harder to close than others. If you can’t close it with your fingers, try using a pair of pliers as explained in Step 4 above.
• Chain is too Short: If you remove too many links from your chain, the chain may end up being too short. You can test this by shifting the bike into the largest gear in the rear cassette and the largest gear in the front crank. If the rear derailleur does not have any more room to pull back, it’s likely too short. If this is the case, you may have to add chain links or get a new chain.

Preventative Measures: Keeping Your Chain in Good Shape

While knowing how to fix a broken chain is essential, preventing one from breaking in the first place is even better. Here are some tips for maintaining your chain and prolonging its life:

• Regular Lubrication: Lubricate your chain regularly using a bicycle-specific chain lube. A dry chain is a happy chain and will perform better, last longer, and protect other drivetrain parts.
• Regular Cleaning: Clean your chain to remove grit, grime, and old lubricant. This can be done with a chain cleaning tool and degreaser.
• Inspect for Wear: Inspect your chain regularly for wear using a chain checker tool, which will indicate when the chain is stretched past its limit. Replace the chain before it causes damage to the other drivetrain components.
• Smooth Shifting: Shift gears smoothly and deliberately. Avoid shifting under heavy load and don’t jam your gears.
• Correct Chain Length: Ensure your chain is the correct length for your bike. A chain that is too long or too short can cause problems, and lead to damage and breakage.
• Professional Inspection: If you’re not comfortable performing maintenance yourself, take your bike to a professional bike mechanic for regular check-ups and maintenance.

Conclusion: Ride On!

A broken bicycle chain is a common cycling mishap, but it doesn’t have to ruin your ride. By understanding the causes, gathering the necessary tools, and following these steps, you can confidently fix a broken chain and get back on the road. Remember, regular maintenance and proactive care are essential for preventing future issues. So, take the time to learn these skills, and you’ll be a more self-sufficient and confident cyclist. Happy riding!