If your bike has been sitting outside for a while, or if you live in a wet climate, chances are that at some point you’ll end up with a rusty bike chain. Rust on your chain is no good–it creates additional friction, places wear on your other drivetrain components, and makes the chain more susceptible to breakage.
The good news is that a rusty chain is a relatively easy fix. You can either clean the rust off the chain, or–if it’s really bad–replace the chain all together.
Whether you should clean your chain or chuck in the trash, is dependent on how much rust we’re talking about. Are there are a few rusty spots, or is the chain completely covered in rust?
If the latter, it’s time for a new chain. Fortunately, a new chain is relatively inexpensive and fairly easy to replace yourself. If you’re not comfortable doing your own work, take the bike into your local bike shop for some help.
When choosing a new chain, you’ll want to look for one that is made for your specific drivetrain. On your rear cassette, do you have 7 rings, 10 rings, or more? If you have 7 gears on the cassette, for example, you’ll want to get a 7-speed chain.
The first step is to simply clean your chain is you normally would. If you have minimal rust, this might be all you need to remove it.
You’ll want to use a degreaser. We recommend Muc-Off Drivetrain Cleaner or Pedro’s Pig Juice Cleaner.
If the chain isn’t too rusty, you can leave it on the bike for this step (This is obviously the easiest option). If the chain needs a lot of work, however, you’ll want to remove the chain and actually let it soak in the degreaser.
To do this, flip your bike upside down to balance on the saddle and handlebars, or place it in a workstand if you have one. Then, take pictures of your chain so you know exactly how to re-assemble everything. Pay particular attention to where the chain threads thru your rear derraileur.
Once your bike is stable and you have your photos, you’ll need to look for a masterlink. This is a single link on your chain that looks a bit different from the others and has a special pin/slot connection.
If you chose to leave your chain on the bike, place degreaser on a wet cloth and use it to wipe down your chain. You can also spray it directly on the chain, let it sit for a bit, and then come back to wipe it off.
If you removed the chain, put in a bucket with the degreaser for about 20 minutes. Afterward, you’ll want to rinse it thoroughly with warm water.
If you still have rust on your chain, it’s time for a little more work. Lime juice has citric acid which helps eat away rust.
Apply lime juice to a steel wool pad and scrub individual spots of rust, until they begin to disolve.
Once your chain is rust-free, you’ll want to get off any remaining residue on the chain. Use warm water and a bit of dish soap to thoroughly rinse the chain.
Then, dry it using an old cloth or towel. Leaving your chain wet will only invite more rust.
The last step is to lube your chain! (If you took your chain off the bike, put in back on before this step).
Any chain lube will do, but if you’re looking for something new we really like Rock N Roll or Tri-Flow. With the bike still propped upside down or in a work stand, apply the lube while rotating your pedals backward so the chain does a full rotation.
Once they whole chain is well-lubed, use a cloth or shop towel to wipe off any excess lube.
Now that your chain is rust-free, you want to try to keep it that way. Rust is caused by moisture, salt, and mud, so keep your chain free of these as much as possible.
The most obvious way to do this is to wipe down your chain after each ride and re-lube it, especially if you rode in the rain or through mud.
We also recommend that you leave your bike outside as little as possible. Store it in a garage or bike shed at home. When commuting to work, ask to bring your bike into your office or cubicle rather than leaving it locked up outside. If you do need to leave it outside, make sure you’re frequently cleaning and lubing your chain.
Antoher option, especially if you live in a rainy climate or near the ocean where rust thrives, is to choose a bike with a belt drive rather than a chain. Priority bikes and the Spot Acme are two great options for bikes with belt drives. With a belt drive, you never have to worry about rust or maintaining a chain.