Installing a new bike chain seems like an idiot-proof endeavor, but it is possible to screw it up. But you can prevent a major issue by asking this question first:
Are bike chains directional?
Not all bike chains are directional, but some models from certain brands are. Directional bike chains are designed in a way that optimizes them for moving up and down the cassette, but they must be installed in the correct orientation to provide these benefits. Get it wrong, and all you’ll get is subpar shifting.
So what exactly is the benefit of a directional chain? And how do you tell if your bike chain is directional?
Find out next!
Which Bike Chains Are NOT Directional?
While there are many bike chain brands out there, we’ll cover the most reputable and popular ones in this article. If you’re shopping for a new chain or just purchased a new bike, it’s likely you’ll come across these brands most often.
These are also the brands I would strongly recommend. You may be able to find cheaper options out there, but the chain is an integral part of your bike, so choosing a quality product is very important.
SRAM Chains Are Not Directional
SRAM is one of the largest bike component companies out there. It’s very likely your bike’s chain, cassette, derailleur and shifters are built by SRAM, as well as your fork and/or shock (SRAM produces these components under the name Rockshox).
SRAM chains are not directional, meaning they can be installed in any orientation. This applies to all their models, whether for road, gravel or mountain bikes, and no matter the number of gears your bike has.
KMC Chains Are Not Directional
KMC doesn’t produce as diverse a range of products as SRAM or Shimano (which we’ll cover below). In fact, they only do one thing: bike chains. But all that focus on one thing means they do it very well. While not as widely used as SRAM or Shimano chains, KMC is a very popular aftermarket choice for bikers needing to replace a chain.
KMC chains are very high quality and are available for a variety of bike drivetrains and gearing options. Like SRAM bike chains, these chains aren’t directional either.
Which Bike Chains Are Directional?
Shimano Chains Are Directional
If your bike doesn’t have a SRAM chain and drivetrain, it probably has one from Shimano. Like SRAM, Shimano makes a ton of bike components, including many different chain models for all types of bikes and gearing options.
Some of these chains are directional, meaning they must be installed in a specific orientation to function correctly. Not every Shimano chain is directional however. This is mostly reserved for their highest performance chains, so be sure to check the package or manufacturer’s website for your specific chain model to find out whether it is directional or not.
Are Master Links Directional?
SRAM and KMC chains may not be directional, but what about the part that holds them together?
The master link.
A master link is the link that connects both ends of your chain and makes it possible to take your chain apart for maintenance and cleaning. No matter which brand you choose (even SRAM’s Powerlock), master links are directional.
The master link must be installed in the correct orientation for it to work properly. If installed backward, it could inhibit smooth shifting, or it could separate while riding, which could result in a crash.
Each master link will have an arrow on the outer plate. When the link is installed, this arrow should be pointing in the direction of the chain’s travel when you’re pedaling forward.
How to Check if a Bike Chain is Directional
Maybe you bought a new chain and threw out the box already. Or maybe you took your current chain off your bike and are now worried you might install it incorrectly. How can you tell if your chain is directional or not?
The best way to be sure is to consult your chain manufacturer’s website. Search for your chain by noting the brand, specific model (which should be stamped onto the chain itself) and the number of gears your bike has (bike chains are sized based on the number of gears they’ll have to shift through) to learn whether it’s directional or not.
Doing some maintenance in the field and don’t have time to get on the internet? Visually inspect your chain. Some directional chains may have an arrow (similar to a master link) to show you which way the chain should be installed.
Can’t find an arrow? Check for a logo instead. Each chain will have its brand logo stamped onto it. If you find the logo on both sides of the chain, it’s most likely not a directional chain. If the logo is only on one side, this is a directional chain. Install it with the logo facing out and you’re good to go!
How to Orient a Directional Bike Chain
For directional bike chains that feature an arrow, make sure the arrow points in the direction of the bike’s travel when you’re pedaling forward. The easiest way to check this is to rotate the chain until the arrow is on the top row. In this position, the arrow should point toward your handlebars.
If you’re facing your bike’s drivetrain, turn the cranks as if you were pedaling forward. Does the arrow move in the direction it’s pointing? If so, good job, you did it right.
If your directional chain doesn’t have an arrow, install the chain so the brand name faces outward. You should be able to read the logo when looking at your drivetrain from the side. If the logo is facing your bike’s frame, you need to remove it and turn it around.
And don’t forget about that master link! The master link’s arrow should also be pointing in the direction of the chain’s travel when you pedal forward.
If you’re having trouble getting the master link snapped back together, here’s a helpful tip:
Connect the master link so it’s on the chain’s top row. While holding the rear brake, apply downward pressure to the pedals. This will add just enough tension to the chain to snap the master link closed. Keep applying pressure until you hear the master link click into place. Visually inspect to make sure it’s secure, and you’re all set!
Why Some Chains Are Directional (Why It Matters)
So if some chains are non-directional and seem to work just fine, why do directional chains even exist? After all, they just seem sort of unnecessary, right?
Well in fact, directional chains aim to improve shifting performance with their unique build.
Directional chains feature an asymmetric design. The inner plates are beveled in a way that makes shifting smoother. As your chain shifts up and down the cassette, the inner plate must climb or drop from cog to cog to change gear. A beveled inner plate makes this transition over the cog’s teeth faster and easier.
Directional chains are specifically designed to improve shifting performance, but to reap those benefits, the chain must be installed the right way. A directional chain installed backward can actually make shifting feel worse than on a non-directional chain, completely defeating the purpose of using one in the first place.