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A smooth-running bike chain is the heart of your well-oiled machine. Your energy is propelled by it. Its metallic silence provides you with a backdrop of pure joy when you are out in the countryside. The chain is your link to cycling bliss.
This collection of parts is easily the most complex and frequently used of the metal components on the bike. It moves every time we pedal, is normally untreated and runs close to the surface we are travelling on. Bare metal running close to grit, rain and mud – your chain needs some TLC to stop it from seizing and rusting.
Do Bike Chains Rust?
The chemical substance of the chain alters with the addition of oxygen from the air. This process is known as oxidation. Adding an accelerant (found in the damp, moist conditions of a garage or lock-up) enhances the process. Your chain corrodes and rusts, if left untreated.
A rusting chain will quickly damage any of the other parts it comes into contact with. So, we’re talking about your crankset, front derailleur, rear cassette and rear derailleur. The performance of those parts will be very seriously compromised very quickly and damage your bank balance.
In addition, the reliability of your bike will be a constant concern. Finally, the noise of a grinding chain is just terrible. Like, fingernails on a chalkboard terrible.
Why Does My Bike Chain Keep Going Rusty?
Oxidation, the process by which your chain rusts, is a constant process. Untreated metallic objects which are exposed to oxygen, will always be prone to rusting. Even if you left your bike indoors, in a dry garage, during the summer. Oxygen in the air will always interact with it.
Your chain will keep going rusty if you don’t maintain a regular, habitual programme of treatment to control the exposure to the conditions which cause rust. In essence, this is a drying and lubricating process. You need to force the damp out and in its place, keep the metal coated to continually repel it.
The parts of your chain that rust are transformed into a new type of material known as iron oxide. It’s easily recognisable as being brown or reddish-brown. Other metals react to oxygen and moisture in the air but we don’t call it rusting.
Acid rain contains sulphur which creates iron pyrite, otherwise known as ‘Fool’s Gold’. Silver is ‘tarnished’ and copper develops a ‘patina’ and these are all further examples of the corrosion of an exposed metal.
But it’s mainly iron or steel that rusts. Why is that? The science part is that these types of metal are in a very low state of thermodynamic stability. A 2019 study written by Muthaiah, Bhatia and Kannan talks about the differing conditions which exist in the environment that determine the rate at which metal objects decompose.
There are some more expensive chains on the market which receive a surface treatment. As well as offering reduced friction to give it a longer life, it also provides a coat to keep away moisture and oxygen.
In the upper echelons of professional cycling, where annual budgets run into the tens of millions for some teams, you will find chains constructed from titanium, or even pre-treated for use only in dry conditions. You’ll find that you get less than 400 miles out of one of these bad boys, all for around £134 / $154.
Does WD-40 Prevent Rust on Bike Chain?
WD-40 offers a handful of products to prevent the progress of rust. Their stable of lubricants, specific rust removers, pentrants and degreasers are well-known. Their multi-use product will protect metal from rust and crucially, displace moisture as well as offering temporary lubrication.
Spraying with WD-40 will drive out the moisture as part of the chain cleaning and drying process. It’s necessary to ensure that as little of this spray comes into contact with disc brakes and any other braking surfaces. WD-40 is a very thin product which does wash off easily and is the subject of much debate about how effectively the standard product lubricates the chain.
How To Stop Bike Chain Rusting [Five-Step Care Guide]
Preventing a bike chain from rusting requires a routine of small and regular actions after a ride. You don’t need to deep-clean your chain after every single ride, unless you are riding in wet, muddy or salty conditions every single time. Keeping your chain from rusting is not the same process as cleaning your chain.
The frequency and intensity of the treatment will depend upon the weather conditions you faced during your latest ride. Remedial treatments are available too if you fail to keep up this regular action. In most circumstances, chain maintenance should only take a few minutes.
Even wiping off mud and dirt and drying the chain will improve the chances of eliminating rust. If you are planning to clean your chain and your bike, it is sensible to clean the chain first, then move onto the bike, because cleaning the chain does spray gunk, oil and road grit back onto the bike.
Bike Chain Care Guide
You’ll need to keep hold of the following for chain care:
- two fingernail brushes usually found next to a kitchen sink
- lint-free rags for drying
- old newspapers to protect your bike and prevent the floor becoming slippery
- water-displacing spray
- cycle-specific chain lubricant
Alternatively, your local bike shop or online retailer will sell you a kit if you’re starting from scratch. Replacement items are available separately.
Because we’re talking about routine and because the most effective time to start is just as you finish your ride, keeping things simple is easiest.
Cleaning or not? – essential checks after each ride
Take a look at your chain after a ride and you’ll soon know how dirty it is. Can you see writing on the outside of each link? Is your cassette and chainset covered in muck and gunk? If you can’t see any imprinted markings, then it’s dirty and needs cleaning before you apply rust-busting lubricant.
If you’ve had a completely dry ride, and the chain is also dry and you can still feel some of the lubricant along the outer of the chain via finger touch, congratulations. If you’re riding the next day and leaving the bike indoors, you shouldn’t need any action. If you do store a bike outdoors, then why not consider giving it some shelter.
After a wet, but not dirty ride
Rainwater will remove prior lubrication from the chain and obviously the moisture will cause rust. You need to dry and lubricate what looks like a clean chain after a wet ride to prevent rusting.
Firstly, apply some water displacing spray. Place some newspaper underneath the chain and a piece between the back wheel and the chain to keep the spray from the rim.
From the chain side, rotate the crank backwards and spray down the chain as it leaves the derailleur or hub gear sprocket. Make sure you coat the whole chain.
Wiping off excess liquid and drying before lubrication
Wiping off excess water-displacing spray and drying the chain is important. Not only does it provide an extra step in removing moisture, it creates the driest, cleanest surface before lubrication.
Wipe off the excess with a lint-free rag. Try to replace this once the rag itself gets covered in gunk, otherwise you’ll be wiping it back onto the chain. Kitchen roll is tricky for drying chains as it tears quite easily and can stick in the links and gear mechanism.
After drying, you will want to lubricate the chain. You can lubricate using an all-weather product, although some prefer a slightly thicker oil in the summer. A small bottle will last months for the average rider and they retail from as little as £3/$3.50.
Most lubrication is dispensed a drop at a time via a thin spout attached to the bottle. Again, rotate the crank arm backwards before you begin application. The best method allows one drop of lubrication per pin. There is no need to lubricate the entire link, it is unnecessary and wasteful.
If you don’t have time to dab each pin, you can rotate the crank slowly and drop the lubrication onto the chain. Just make sure you keep an eye on where you started and be sure to wipe off any excess. The thinner the lubricant, the more likely it is to drip off the chain.
You may wish to put down some cloth below the chain from the cranks to the back of the rear cassette to avoid lubricant coming into contact with the floor. If you use paper towels or newspapers here, you risk the drips seeping through and making contact with the floor.
Cleaning your chain then preventing rust
After a few hundred miles, or more frequently if you’re noticing how dirty the chain is in step one, it is going to need cleaning. This is where the degreaser and brushes come in.
Treat the chain all over with your degreaser. Place the nail brushes in your left hand and clamp them around the chain. Not super-tight, but as if you were squeezing a tube of toothpaste without any actually coming out.
Turn the cranks anti-clockwise from the drive-side and rotate the brushes slowly in your left hand to treat the side, top and bottom of each chain link.
It doesn’t hurt to use these brushes on your cassette, chainrings and the small jockey wheels on any derailleur you have.
You can invest in a chain cleaning clamp which gives your chain a bath and also cleans thoroughly between the links using replaceable brushes and sponges. This is a deep-clean and would be recommended after most off-road rides or perhaps after a really wet ride.
After the chain has had its bath, you then dry it and then carry out the lubrication stage.
A clean chain is an effective chain, so it’s important to ensure that you look to keep your chain free of muck and grit that you pick up on a ride. There is no value in lubricating a dirty chain.
If you apply lubricant to a dirty chain it might play a part in limiting rust. However, the cost to you of applying lube at this point will be to create a glue-like paste which grinds and destroys the chain and all of the parts involved in turning the pedals.