The chains on our bikes deserve much more credit than we often give them. They glide smoothly between the sprockets while barely interrupting our cadence, and they simultaneously absorb all the power of our most powerful sprints. This paradoxical nature comes at a price, however: Over time, the pins and inner links of your chain wear out, causing the pitch of each link to increase. They commonly referred this phenomenon to as “chain stretch,” even though the metal does not stretch in any measurable way. If you don’t replace your chain, it can have a deleterious effect on your shifting, or even leave you stranded on a ride if it breaks.
Fortunately, bike chains are inexpensive to replace, especially if you do the work yourself. Best of all, finding the right chain is relatively simple if you know what components you have. However, there are many pitfalls for over-investing in marginal gains, and it's hard to determine when a little extra smoothness or weight reduction is really worth it. If you’re looking to make your bike feel like new with every turn of the crank while staying within your budget, I’m here to help.
What to consider when buying a bicycle chain
Speeds
The number of sprockets on your cassette or freewheel is undoubtedly the most important variable when choosing a bicycle chain. Especially in the most modern group sets, the entire rear shifting mechanism - which includes the derailleur, cassette/freewheel and chain - relies on incredible precision to work smoothly. The higher the number of gears in a transmission, the finer the chain. Although the difference is only fractions of a millimeter, it’s an astronomical change compared to the width of the sprockets and the gaps between them. A chain with the wrong number of gears will shift poorly, squeaking against neighboring sprockets, or not shift at all. This is not usually a problem with bikes with 8 gears or fewer, as these chains are all the same width, but it is good to know this for any bike with more gears.
Brand
In modern group sets (especially 11 and 12 speed), brands contour their gears and chains to streamline shifting, and they all do it differently. This can sometimes lead to awkward shifting and jumping into mismatched transmissions, so try to match the same brands - Shimano with Shimano, SRAM with SRAM, and Campagnolo with Campagnolo. I’ve had some success with a SRAM chain on my Shimano Ultegra 11-speed setup, though I think there was a bit of luck involved. Some brands, like KMC, offer chains that can fit all brands, but these diplomatic designs involve some compromise in terms of smoothness. Also, the key links, the attachments that make your chain a loop, are usually gear and brand owners as well, and the incorrect size could either not fit at all or come apart as you ride - neither situation is ideal.
What about single gears?
Since a single-speed setup allows you to ride without shifting, most of the problems associated with mixing brands don’t arise. However, these parts have their own sizing: ⅛-inch chains are standard, with some 3/32- and 3/16-inch components as well. Anything thinner (i.e., everything else) won’t fit the vast majority of single-speed sprockets and chain rings. You can try using an old chain, sprocket and chainring from a multi-speed transmission, but beware: These parts, designed for smooth shifting, are literally designed to drop the chain more easily. Having tried this setup several times, I can confirm that it gets annoying quickly.
Other considerations
Compatibility issues aside, it’s important to make sure the finishing details of a chain serve your purposes. If you want a lighter chain to give you a little of a racing advantage, you’ll want to look into chains that save grams, such as hollow pins or extra thin plates. If toughness is more your ideal, look for different finish treatments, such as nickel, chrome and other coatings like KMC’s proprietary Rustbuster, which helps fight rust.
Another thing to note is that some chains come to different lengths, but I almost always recommend going with the longest. Even if you end up with a bunch of extra links, it’s better than not having enough, and we can use later the leftovers to replace defective links. One of my colleagues at my shop had entire bins full of these bonus strands, and they were an invaluable reserve, especially when the pandemic caused a shortage of parts.
How we rated these bike chains
In my years as a mechanic, I’ve worked with all brands of components, and I’ve replaced enough chains to know which one to use in almost every situation. Therefore, I chose these chains based on what I would normally use in a professional repair. I also discussed the topic with other Bicycling editors, as well as members of the cycling community in my hometown.
1. NX Eagle chain
I suggest not to go crazy with mountain bike chains. They fill up with grit much faster than road chains, and the likelihood of bending or breaking them is much greater when shifting on a monstrous 10-50 tooth cassette. SRAM’s affordable NX chain is compatible with the brand’s entire 12-speed mountain range and promises to be durable. It doesn’t have all the features of a GX or X01 chain, like hollow pins or chrome plating, but those kinds of differences are ultimately negligible in real-world applications, especially if you take care of your chain between rides.
Buy: NX Eagle chain
2. Ultegra Deore XT 12-Speed
The most interesting part of the Shimano group set line is that the parts are compatible with each other. This means that a Shimano chain can reliably fit all Shimano drivetrains of the same speed, whether they are mountain or road. This Ultegra option is no different, fitting perfectly with all Shimano 12-speed group sets. Its chrome-plated design is smooth and corrosion-resistant, and it’s strong enough to handle the extra power of an electric bike motor without being too heavy.
Buy: Ultegra Deore XT 12-Speed
3. Record 11
Campagnolo is notorious for not playing fair with other brands. Despite this, its products are still popular, especially in the high-end market. Cyclists who swear by Campagnolo appreciate the attention to detail in its components, while others, especially people who work on bikes for a living, decry its sophistication. The Record 11 chain does not differ from this polarization, offering a top quality chain that requires an equally expensive tool to install properly. The plates are so thin that most normal chain tools aren’t precise enough to avoid damaging them, but this thinness allows for a quick and quiet gear to change every time.
Buy: Record 11
4. X10
Having a chain that can do it all is seriously handy, especially on the job. I don’t always like brand name chains, but when they work, they absolutely work. KMC’s X10 is comfortably compatible with every chain in the 10-speed pantheon. It’s not the smoothest shifting in the world, but it’s consistent and reliable, which is all you can ask for sometimes.
Buy: X10
