A bike chain that keeps coming off when riding can be annoying. Besides that, it becomes more dangerous when the chain comes off in the traffic. I recommend setting up the bike well to minimize the risk of it happening.
How to fix a bike chain that keeps falling off depends on the cause. But I recommend the adjustment of the rear and front derailleur limit screws. If the problem persists, replace the chain and drive-train.
It is a daunting experience to identify the exact cause of the bike chain coming off since it involves many factors. My research will show you the possible reasons for bike chain coming off and quick tips for fixing it.
How Does a Bike Chain Work?
A roller chain is an essential component on a bicycle since it enhances propulsion. The pedals transmit power through the roller chain to the drive wheel and propel the bike. Most bike chains are made from nickel-plated steel, alloy steel, or carbon materials. The chain strength usually depends on the bicycle type. An electric bike has a robust chain since it uses more power than regular bicycles. Therefore, the electric bike chains have a higher strain.
Bike chains are fixed on the front side teeth of cranksets and rear chainring. The gear derailleur helps regulate the bike chain position. The chain will keep moving due to gear shifts to suit the rider’s desire. It is also a clear indicator that the bike chain is part of gear sets.
7 Possible Reasons that Can Make Your Bike Chain to Keep Falling Off
Many cyclists rush to reattach a bike chain that falls off when pedaling hard without identifying the exact cause. However, it can be challenging for novice riders to figure out the underlying issue. Below are the possible reasons why your bike chain cannot stop coming off:
Bent Cog Teeth
Bent cog teeth on the cassette and chainring will bring misalignment with the bike chain. The alignment problem causes the bike chain to keep falling off even with a single speed. The issue occurs due to incorrect mechanical contact between the chains and cogs. I recommend removing the chain and inspecting your cassette and chainring teeth.
Stretched and worn-out chain is the leading reason for bike chain dropping off. The slipping issue occurs on the front chainrings when pedaling hard. Several mileages of hard pedaling causes the chain to stretch and damage inner rollers. Always use a special ruler to test the chain’s health before riding for a long distance.
Remember to replace the worn-out and stretched bike chain to avoid damaging the drivetrain components in the long run.
Worn Out Drivetrain
The worn-out drivetrain has hooked and shark-teeth looking on the cogs. The problem is due to riding thousands of miles on the drivetrain. The cog teeth misalignment on the drivetrain will make the chain slip more often when riding at any speed. The best option is to replace the drivetrain to avoid the chain slipping issue.
Excessive Chain Angle
The bike chain will keep slipping off when using the largest ring in the back and front due to excessive slant chain angle. The excessive chain angle stresses the hardware to rub the chain and causes falling off. I recommend sticking to an intermediate gear combination to prevent excessive chain angle.
Clogged and Dirty Chain
A bike chain clogged with dirt, grime, and grease is vulnerable to slipping off. The problem is common among those cyclists who don’t clean the bicycles more often. I recommend using cleaning chain oil to remove the dirt, grime, and grease. The trick will help prevent the bike chain from falling off.
Misaligned Rear and Front Derailleur
Derailleur plays a crucial role during the shifting system. The front and rear derailleurs have limited screws that prevent the bike chain from slipping off. If there is a misalignment between the rear and front derailleur, the chain will keep falling off. I recommend inspecting the area and adjusting the limit screws.
Incompatible Drivetrain Components
Most bike chains are the same but have different specifications. It is something that novice cyclists will never spot during their early riding phase. Drivetrain system parts work in perfect harmony with specific chains. If the chain is incompatible with these components, it will keep falling off.
Derailleur Hanger Alignment Issue
Modern bicycles have an aluminum metal frame for holding the derailleur. The metal piece should be in perfect vertical alignment with the cassette cogs. If the derailleur hanger has a slight bend to the inner side, the derailleur will lose its alignment with the cassette and cause the chain to slip when shifting gears.
How to Fix a Bike Chain that Keeps Falling Off
There are many methods for fixing a bike chain that keeps falling off frequently. But the golden rule is to determine the exact cause and try to fix it immediately. Below are quick solutions to fixing bike chain that slips off more often:
Method 1: Use a Chain Tension
A bike chain tension is also known as a chain guide. The gadget will stop your bicycle chain from slipping off the chainring while riding. The chain guide is ideal for descending since it keeps the bike chain in a perfect position. Buy a lightweight chain guide that suits the chainring size of your bicycle.
Method 2: Reattach the Fallen Chain
The method is ideal for scenarios where the bike chain falls off for no appropriate reason. Turn the bike upside down to reattach the chain with ease. Push the rear derailleur towards the handles to loosen the chain and use a single hand to return it on the rear gear. Use the other hand to back-pedal slowly and slip the chain in the right position.
Method 3: Use a Chain Catcher
A chain catcher is an excellent instrument for stopping the bike chain from slipping off the chainring. It is an excellent barrier that holds the chain in position when cycling.
Frequently Asked Questions
Why a Bike Chain Gets Loose?
Bike chain gets loose due to worn-out parts on the drivetrain. It forces the chain to jump and slip around when riding the bicycle.
When Should We Change Bike Chain?
Every 2000 miles. The trick will help avoid accelerating the depreciation of cassette and chainrings on your bicycle.
How Do I Know If My Chain Is Worn?
Signs of a worn-out chain are grooving chain pins and an increase in inner bushings diameter. A worn-out chain will also lead to slow and inconsistent gear shifting.
When Should I Replace My Bike Chain Rust?
Replace the bike chain that is rusting away for more than six months and covered with rust about 50%. A chain with rust is more vulnerable to breakage.
How Long Should a Bike Chain Last?
The bike chain can last anywhere between 500 to 5000 miles, depending on your riding style and chain type. But the bike chain can last for many years under good maintenance.
A bicycle with a chain that keeps falling off can be more frustrating and risky to ride in heavy traffic. I highly recommend fixing the problem to avoid possible road carnage. The bike chain falling off is due to several factors mentioned in the article above. But it can be challenging to troubleshoot the bike and figure out the exact issues.
I hope the tips on how to fix a bike chain that fell off in this article will help you sort out the bike chain problems. Feel free to share with friends or family within your community.
Hello, this is Evan Larry. The chief editor of this site, “eBikeBuster.” After completing my graduation in mechanical engineering, I worked for a renowned e-bike manufacturing company as a technician. I had worked there for almost six years, and later I quit the job and started my own business where I sell different types of e-bike and their tools and accessories. I created this site, eBikeBuster, to guide people, who are new to an e-bike and don’t have proper knowledge about its tools, accessories, and maintenance.