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Bike chains slipping is a common issue that all bikers have to face from time to time. It happens when your chain skips between gears while you are riding, shifts twice instead of once, or refuses to shift when you change gears.
Chain slipping after putting on new bike chains isn’t something unusual.
Luckily, you can sort out this problem on your own without the help of any mechanic or professional. The solution can be adjusting tension in shifting cables, changing worn-out parts, or cleaning the drivetrain components.
However, it is crucial to know where exactly the issue lies to avoid wasting your time and money.
In this article, I’ll look at the 10 most common reasons why new bike chains might be slipping, and exactly what you should do to fix each issue.
10 Reasons Why Your Bike Chain Might Be Slipping + Fixes
1. Adjusting Cables Tension
Most of the time, the slipping of a new bike chain is caused by loose cables.
The new shifting cables stretch a lot during the first few rides. The cables stretch way too far with time, and that’s when the problem arises, and your chain starts to slip between gears.
However, adjusting tension for these stretched-out cables isn’t rocket science and can be done very easily.
According to the bike builder and expert mechanic Abby Hippler,
“Your chain – more accurately the cables that connect your shifters to your derailleurs to move the chain from cog to cog – need their tension adjusted – a fix you can most likely make without interrupting your ride.” (Source)
Follow these steps to adjust the tension quickly:
- Put your bike on park mode and set your chain on the smallest cog of the rear cassette by pedaling manually. Press the shifter to double-check. If the chain doesn’t move up a gear, you need to add tension.
- Twist the right barrel adjuster to turn it away from you. It is a small part located at the backside of your derailleur.
- Press the shifter again to check if the chain moves up from the smallest cog now. If the problem still persists and the chain doesn’t move up, repeat the entire process. Keep turning the adjuster until you find the correct spot and movement, and the bike chain shifts how it is supposed to.
- The same process can be done on the front derailleur. But you’ll need to turn the barrel adjuster in the opposite direction for the front derailleur (turn it towards you).
2. Rear Derailleur Adjustment
Rear derailleur hangers in most modern bikes are made of fragile materials.
If you experience a massive bump or pedal under pressure, there’s a good chance that your rear derailleur hanger may be bent or is out of alignment.
A bent or unaligned rear derailleur can disturb the tension in shifting cables, which causes the chain to slip.
If you observe that the derailleur hanger is crooked, you can bend it straight.
There are some affordable tools that can be used for this purpose. Make sure you know how to use these tools before applying.
Otherwise, take the hanger to your local bike shop for service.
Verify the alignment of the rear derailleur by looking carefully at the rear wheel. You’ll have to observe closely to decide whether the alignment is correct or not.
A nut connects the shifter cable with it, to align the derailleur, rotate it clockwise and counterclockwise to move the pulley up and down. Keep adjusting this nut until the pulley is aligned correctly.
If adjusting and bending don’t solve your alignment issue, consider investing in a new rear derailleur.
3. Positioning Front Derailleur
A poorly positioned front derailleur body can also be the reason for your shifting chain.
Most people prefer not to do this adjustment personally and go to a professional mechanic to get these complex and confusing adjustments set. You can check the measurements to ensure the front derailleur of your bike is positioned well with the help of the following techniques.
The most common issues with the front derailleur position are limited screw setting and incorrect height of the derailleur.
Position the derailleur arm over the outermost ring. The distance between the outer cage of the derailleur and the chainring should be as close as it can be without making contact (approximately 2 mm). Many experts suggest using a thin coin as a gauge.
To reposition the front derailleur, you need to loosen the mounting bolt. This bolt holds the derailleur onto the frame and is located on the opposite side of the seat tube.
You may also have to loosen the derailleur cable to reposition it freely.
Once the derailleur is free, reposition it to the proper distance from the outermost chainring.
4. Worn Out Cogs
Worn-out cogs can also be one of the reasons that might be causing your new bike chain to slip. Chainring and chain cassettes wear out eventually, no matter how well maintained your bike is.
According to Chris McKenney from SRAM,
“Changes in tooth shapes and skipping under load are signs that your cassette needs replacing. It is very hard to see the changes in shape until they are well past the end of their lifespan, but everyone has likely experienced a new chain skipping on worn cogs. It’s a well-known phenomenon.” (Source)
Making sure that the cogs of the chainring aren’t worn out is also crucial because old and shabby sprockets can ruin your newly installed chain very quickly.
A couple of worn teeth are usual but if you notice any more than that, replace the cassette as soon as possible before it damages your chain.
Changing the chainring is a straightforward job and takes minutes.
However, you may need a couple of specialized tools: a cassette tool and a chain whip. Remember to get the correct standard for the type of chainring you have to install. Refer to your owner’s manual.
5. Cleaning Sprockets
Filthy sprockets of chainring not only cause sluggish shifting between gears but also lead to premature wearing out of the chain and chainring.
That’s why checking signs of dirt and grease accumulation on the sprockets before installing the new bike chain is necessary.
Moreover, it would be unfortunate if you threw away a chainring when you could have solved the problem just by sparing a few minutes to clean it.
To clean away all the dirt on the chainring, you would only need a degreaser and an old toothbrush.
After removing the cassette from the wheel, place it in a bowl full of degreaser in a way that it is completely submerged. Leave it for several minutes. Once it is entirely soaked, scrub the sprockets using the toothbrush until clean. Don’t forget to re-oil before putting it back in place.
Routine cleaning using a rug or pipe cleaners can save you from this labor every once in a while.
6. Change Shifting Cables
Clean and drag-free shifting cables are a must for the mechanical drivetrain in bikes.
If the shifting cables are rusty, kinked, or old, they are definitely causing your new bike chain to slip and hindering the shift between gears.
Swapping out and replacing shifting cables on a regular basis is essential for normal and smooth functioning of the bike. It is also recommended to replace the housing around the cables as well while changing them.
To remove the old cables, you need to shift your bike into the smallest gear and turn the adjuster all the way in. Loosen the clamp on the derailleur and pull the cable out.
Similarly, locate the cable’s entry point on the shifter and remove the cable from the bike.
Now to install the new cables, measure the appropriate length for it. You can use the old cables to get the idea.
When cutting the cable short, it is always wise to leave a few extra inches just to be on the safe side.
Next, insert the cable in the shifter and close it.
Route the cable to the derailleur, according to the intended position.
Pull the cable tight and fasten the clamp on the derailleur.
Cut the extra cable and stick an end on it. The only thing left is to adjust the derailleur, and you’re done.
7. Consider Investing in a New Shifter
Bad quality or old shifters can be another factor causing the shifting cables to lose tension and making the chain skip gears in between.
The shifters might have been slightly damaged if you have been paddling on a rough and bumpy track. Broken shifters can cause undesired gear changing and make the chain slip gears.
8. Verify that the New Chain is Compatible
In case you forgot to check the manufacturer’s instructions before installing the new chain, there’s a chance that the chain might not be compatible with other drivetrain components.
If so, you might run into multiple problems, including gears malfunctioning and slipping for the chain.
Therefore, it is necessary to check the compatibility guidelines regarding the new and old components before you purchase a bike.
9. Length of the Chain
The length of the chain is another factor that can affect the performance and functioning of gears.
If the new chain is too long, it can cause slipping and dropping between the gears. If the chain is too short, it can stress the rear derailleur and drivetrain and even damage them.
Typically, when you buy a new bike chain, it comes with 116 links, which may be too long for most bikes.
In order to shorten the chain, you need to remove a few links.
The easiest way to measure the correct length for your new bike chain is to hold it next to the older chain and shorten it to the length of the older chain.
Note: With time, bike chains stretch as you use them. So keep in mind that the older chain should be a little longer to compensate for all the stretching over time.
Another more precise method to measure the correct length of your new chain is called big-big.
Put the chain around the largest chainring in the front and the largest sprocket in the back (without putting it through the rear derailleur).
Leave one more inch or one link for the derailleur, and make sure the chain is tensioned correctly. That’s it, and you get the correct length for your new chain.
10. Avoid Too Much Lube
Too much lube will cause the chain and the sprocket teeth to lose contact, leading to the chain slipping frequently. It makes the sprockets and chainrings really sloppy for the chain to grip them properly.
Excessive lubing will also make the chainrings and chain absorb too much dirt and dust that will decrease the longevity of both parts.
If you have greased the chain too much, clean the chain and entire drivetrain properly. When re-greasing, use just a little amount of lube.
Here’s what to do to figure out the issue making your newly installed bike chain slip:
- Adjust cable tension
- Position and align rear derailleur correctly
- Position and align front derailleur correctly
- Change worn out chainrings
- Clean sprockets properly
- Swap out old shifting cables
- Replace the broken shifters
- Check chain compatibility
- Verify the length of the chain
- Do not lube too much
At first, you may feel exhausted even at the thought of detecting the problem on your own and fixing it. But usually, the culprit behind your new bike chain skipping gears or shifting more than once is not something too complex.
Once you check every component one by one, observe if it is appropriately aligned, and any signs of damage, then you will be able to figure out the underlying issues very quickly.
Then using simple methods and techniques mentioned in the article, fixing it isn’t hard at all.
I advise at least adjusting the tension in the shifting cable and derailleur before replacing any parts.