Imagine this: You’re out on the bike trail, gasping for air as you summit the hill. Feet away from the top, you give your best effort to those last few pedal strokes and…
Suddenly your pedals feel weightless, and you can’t push the bike forward at all. You hop off your bike, and sure enough: your chain is completely broken.
Looking down, you remember the last five miles of rough riding, and realize your day just got a lot more complicated.
Out of all of the components on your bike, your bike chain does a lot of the heavy lifting to keep things rolling. It’s impossible to overstate how important it is to keep your chain in good condition, and replace it at the right time.
While most bike chains will last you 2000-3000 miles, the way that you ride and how you take care of your chain will drastically influence the life of your chain. There are specific warning signs to watch for, and ways to increase the life of your bike chain.
In this article, I’m going to break down how to watch for bike chain wear, and how different riding styles impact your chain health.
How Often Do Bike Chains Break? Warning Signs to Watch For
If you’re a casual commuter or short-distance rider, you can safely expect a long time between chain replacements. 3000 Miles is years’ worth of riding, and riding on the road is generally better for the shelf life of your chain.
However, if you’re riding centuries on the weekends or ripping through mountain trails, you’ll see a much faster degradation of your chain. The high force placed on your chain as you climb hills and hustle through uneven terrain will stretch and wear it out over a much quicker timespan.
There are multiple ways to test if your chain is at risk of wearing out as you ride. Here are a few, in order of complexity and accuracy:
- Make sure the bike is stable, either by using a bike stand or propping it up on the kickstand or a wall.
- If you have a geared bike, shift into the smallest gear on your rear cassette and the largest chainring in the front.
- Grab the chain at the front of the bike, where it wraps around the chainring
- If you can see significant daylight between the chain and the chainring, your chain has stretched enough that you should replace it as soon as possible.
- If you have a hard time stretching it any further, you’re fit to ride!
This method is quick and easy, and will give you a good ballpark estimate of when to replace your chain. While there are definitely more accurate measurements, this method will work fine for most casual riders.
If you want more accuracy, the Ruler Test will ground you in actual measurements.
- Again, stabilize your bike and shift the gears into the smallest rear cog and largest front ring.
- Pick a rivet on the flat part of your chain, and line it up with the 0 mark on a 12” ruler.
- Count the rivets along the ruler: You should get 24 rivets, with the last one lined up to the 12” mark.
- If your chain is off of that by more than 1/16th of an inch, you should look into replacing your chain.
This method helps to increase your accuracy, but the method is only as effective as the mechanic. There are longer chains on the market too, so if you count an extra rivet, that may be the culprit.
If you aren’t able to get a consistent read, or struggle to line everything up perfectly, then you’ll want a tool made specifically for the job.
Using a Chain-Checking Tool
For those who want maximum accuracy, a Chain-Checker is purpose-built to provide a ruling on whether your chain is worn. This tool uses the space between chain links to give you an accurate estimate of chain wear and stretching.
In general, you want to make sure that your chain is clean and free from gunked up lubricant. Even a small amount of built up dirt will affect how the tool is able to fall in between the chain links, throwing off your measurement.
Most mechanics agree that a .5% wear reading signals that it is time to get your chain swapped out. If you pass .75% wear, proceed immediately to your local bike shop or workshop to get a new one! Nothing is worse than riding on faulty components and feeling it give out on you.
Park Tool has a great guide on using different kinds of Chain-Checker, which can require some subtle adjustments. They sell three different versions, which can be fine-tuned for different styles of chain and wear.
How Often Do I Replace My Bike Chain?
If you care about the life of your bike’s drivetrain, you probably want to replace your chain every 2000 miles, max.
When it comes to city or casual riders, you can get away with stretching it to 3000 miles, but ultimately the price you’ll have to pay is in the more expensive components of your bike, like your cassette.
This is because your chain doesn’t exist in a vacuum: If the chain you’re using is dirty, it’s going to transfer all that gunk into the rest of your drivetrain. If the chain is too stretched out, it will begin to wear on the gears as the imperfect fit rubs new grooves on your cassette.
It is FAR BETTER to be conservative about chain wear, replacing at the first signs of degradation, than to hold onto it until it snaps. It may be cheaper in the short term to not fix anything, but a 50$ chain replacement is much less expensive than a $300 cassette replacement.
If you ride in hilly terrain, or like to cruise in higher gears, you will subject your chain to more stress over time. Be sure to check your chain for wear more often if this applies to you.
How Long Do Mountain Bike Chains Last?
When it comes to mountain biking, you are placing your chain under the most rigorous conditions that a bike can be put through. Steep uphills, uneven terrain, and the ever-present possibility of colliding with plants and rocks make for a lot of strain on your whole bike.
If you’re regularly tackling trails, you can expect about 1500 miles at most from your chain. Even within that range, you want to check it for wear and tear every few rides, just to make sure nothing got damaged.
How Long Do Road Bike Chains Last?
Road biking is generally less stressful on your bike chain than mountain biking, but the long-distance aspect of riding road can quickly eat into your chain. Especially with the incredibly expensive drivetrains that road bikes can run, you don’t want to let your chain start to degrade the quality of the rest of your drivetrain.
Check the chain every 500 miles, and it’s best to replace it at 2000 miles for the longevity of the rest of your bike.
How Long Do Ebike Chains Last?
When E-bikes were first coming onto the scene, the lack of dedicated components for the extra power of a motorized bike meant that E-bikes would eat chains for breakfast. With the force of your pedal stroke multiplied by a motor, E-bikes are generating much more friction and pressure on the links in your bike chain.
All that being said, most E-Bikes are now assembled with chains that are built specifically to withstand the higher torque E-Bike motors place on their chains. As a result, you can treat your E-Bike chain similarly to a normal one: check for stretching using the manual test above, and replace every 2000-3000 miles.
A Happy Chain Makes a Happy Bike
Your bike chain is a crucial component of your bike: it impacts so many functions of your bike, and the difference between a well-maintained chain and a rusty old one is palpable.
Remember, keeping your chain cleaned and lubricated is the best way to enjoy a long life from your bike chain. Whenever you don’t want to take the 10 minutes to maintain your bike, remember the cost of inaction.
Break out that cleaning kit, and get your chain in tip-top shape. You’ll feel the difference every time!
Alex Mwangi is the creator of Outdoor Right and an outdoor enthusiast. During his free time he enjoys riding his road bike or traveling the world looking for his next adventure.