How to clean a bike chain and remove rust from it

Short answer: how to clean a bike chain is five jobs: degrease, scrub, rinse, dry and lube. Spray a bike degreaser onto the chain, cassette and jockey wheels, and scrub with a stiff brush or a clip-on tool while backpedalling. Rinse, dry the chain through a rag, then put one drop of lube on each roller and wipe it. Light rust comes off the same way. A chain that stays stiff, or measures worn on a chain checker, needs replacing.

Does your chain need a wipe or a degreaser?

Run a clean rag around the lower run of the chain while you turn the cranks backwards. If the rag comes away with a grey film and the chain looks silver underneath, wipe it and add fresh lube.

If the rag comes away with black paste, or you can feel grit in the links, the chain needs a degreaser. That is the whole decision, and it takes thirty seconds at the kerb.

Cyclescheme's chain care guide gives a second test: if you cannot read the maker's name stamped on the side plates, the chain is due a clean.

Canyon puts a commuter's full clean at around once a week. Cycling UK suggests every 160 km on the road and more often through winter. The rag tells you what your own commute is doing.

How to clean a bike chain without taking it off

Cleaning a bike chain on the bike is seven steps: set up, knock off the dirt, degrease, scrub, rinse, dry, then lube and wipe. You need:

• A bike-specific degreaser
• A stiff brush
• An old toothbrush
• Three rags
• A bottle of water or a hose on a gentle flow

Muc-Off Bio Drivetrain Cleaner is one widely stocked degreaser. Warm soapy water shifts light dirt, as Cycling UK allows, but it will not cut old oil.

Add chain lube for the season, gloves and cardboard under the bike. A clip-on chain cleaning tool is quicker and less messy, though Canyon's guide is right that brushes do the same job.

1. Set the bike up

Lean the bike against a wall or put it in a workstand. Shift to the middle chainring, or the single ring, and a sprocket near the middle of the cassette, so the chain runs straight under a little tension.

On a disc-brake bike, cover the rear rotor with a plastic bag, because degreaser on the rotor makes the brake squeal and glazes the pads.

2. Knock off the loose dirt

Brush the chain, cassette and jockey wheels dry, or rinse them with clean water. Muc-Off's first step is a rinse, so the degreaser works on grease rather than on mud.

3. Apply the degreaser

Spray or brush the degreaser along the chain while you turn the cranks backwards. Then do the cassette, the chainrings and both jockey wheels, the two small wheels in the derailleur cage.

Muc-Off says to leave its Bio Drivetrain Cleaner for up to one minute before agitating. Do not let it dry on the chain.

4. Scrub

With a clip-on tool, fill the reservoir, clamp it around the lower run and turn the cranks backwards two or three times. Then press the brush button and keep turning until the chain comes out clean.

Without a tool, hold the stiff brush against the chain from below and from the side while you pedal backwards. Use the toothbrush on the jockey wheels, and pull the edge of a rag between the sprockets.

5. Rinse

Rinse the chain, cassette, chainrings and derailleur with a gentle stream until the degreaser has gone. Muc-Off is specific that all of its formula must be removed. Aim the flow from above and behind the cassette so the run-off misses the rotor.

6. Dry

Spin the cranks backwards to throw water off, then run the chain through a dry rag until the rag stops darkening.

Cycling UK allows five to ten minutes in warm weather for the rollers to dry inside. A squirt of a water-displacing spray such as GT85 speeds that up on a cold evening, and you still lube afterwards.

7. Lube and wipe

Put one drop on each roller of the lower run while you turn the cranks slowly backwards. The LCC guide, written with London Bike Kitchen, says one drop per link and no more than two or three turns of the cranks.

The rollers need oil. The side plates do not, and oil on the outside only collects grit. Run through the gears, wait fifteen minutes, then wipe the outside until the rag comes away almost dry.

Deep clean: taking the chain off and soaking it

Take the chain off when the brush leaves grit inside the rollers, or when you are switching to wax. Split it at the quick link, the removable joining link, with quick-link pliers, covered step by step in our guide to fixing a bike chain.

Road.cc's method drops the chain into an old drinks bottle with a couple of hundred millilitres of degreaser or white spirit. Shake it, then fish the chain out with a spoke. Label the bottle and keep it away from children.

Keep the chain's soak to minutes. KMC says aggressive degreasers loosen the factory grease from the pins, let dirt in and shorten the chain's life. Canyon adds that a long soak can leave the steel prone to cracking. Rinse, dry the chain completely, refit it and lube it before the bike goes back outside.

How to remove rust from a bike chain

Surface rust on a bike chain comes off with a penetrating spray, ten minutes of patience and a wire brush, followed by a normal degrease and lube.

Orange bloom on the side plates after a wet week locked outside is surface rust. Rust inside the rollers, links that will not bend and pitted metal are a different problem, covered in the next section.

With a penetrating spray. WD-40's own guide coats the chain with its Multi-Use Product, leaves it for ten minutes and scrubs with a wire brush until the rust lifts. Repeat on stubborn patches and wipe the flakes away. Flex each stiff link sideways between your fingers until it moves freely.

Then degrease the chain exactly as above, because the spray loosens rust but leaves nothing behind that lubricates. WD-40 states in the same guide that its Multi-Use Product should never be used to lubricate the chain.

With what is in the kitchen. Cleanipedia's rust guide uses a paste of equal parts baking soda and water, left on the rust for 15 minutes and scrubbed off. It also soaks a removed chain in white vinegar for 15 minutes and rinses it straight after, because vinegar keeps corroding metal. Take that with a caution from the chain maker.

KMC says never to use acidic or alkaline cleaners on a chain, because they damage it and in extreme cases lead to breakage. The same warning covers chemical rust removers, which belong on frames and bolts.

If you try a kitchen method on light rust, keep the contact short, rinse straight away and dry the chain fully.

A rusty chain is a dry chain, so the lube step is part of the rust removal. Apply wet lube, wipe the outside, and check the chain again after the next wet ride.

When a rusty chain needs replacing rather than cleaning

Replace the chain when:

• A chain checker drops fully into the links at 0.5 per cent on an 11 to 13-speed chain. On a 6 to 10-speed chain the figure is 0.75 per cent.
• Links stay stiff after cleaning and flexing.
• The rollers are pitted.

The percentages come from BikeRadar's workshop guide to chain wear. SRAM's own tool checks for 0.8 per cent, and SRAM tells owners to replace the chain once wear passes that figure.

A chain checker costs around £10, in Cyclescheme's figure, and gives a yes or no in seconds. Hook one end into a link and try to drop the other end in.

If the checker sits above the chain, the chain is fine at that mark. If it drops in flush, the chain has reached that wear. BikeRadar recommends measuring at three different places, because chains do not wear evenly.

KMC's no-tool check is to lift the chain away from the big chainring at the front. If it lifts more than half a link, measure it.

The ruler method needs no tool at all:

• Twelve links of a new chain measure exactly 12 inches from pin to pin.
• At 12 1/16 inches the chain is 0.5 per cent worn.
• At 12 1/8 inches it is 1 per cent worn, and BikeRadar says the cassette needs replacing with it.

A stretched chain rides high on the teeth and wears them to match. The symptom is a chain slipping forward under hard pedalling, and our guide to gears skipping or not changing explains why more cable tension will not fix it.

How long a chain lasts depends on load, weather and cleaning, so treat published mileages with suspicion. KMC suggests checking wear every 500 km on dry roads and every 150 km for everyday riding in poor conditions, which describes a London winter.

Which chain lube for UK weather: wet, dry or wax

Use wet lube for commuting between autumn and spring and on any wet or salted road. Use dry lube in dry summer weeks, and wax if you will strip the chain fully first. The notes below take the manufacturers' own words.

• Wet lube. For rain, road spray and salted winter roads; Muc-Off says it "will not wash off easily". The downside is that it picks up dust and grit and is harder to clean off, as Muc-Off and Cycling UK both note. Finish Line's instructions are one drop per roller on a clean, dry chain, wipe off the excess and let it dry for five minutes. UK examples are Muc-Off Wet Chain Lube and Finish Line Wet, sold for "wet, salty and coastal roads".
• Dry lube. For dry summer roads and dusty paths; it dries to a finish that does not attract dirt. Muc-Off's own caveat is that it is "prone to washing off of your chain in the rain". Muc-Off's method is to clean the chain, let it dry completely, apply to the inside of the chain, wipe, and wait 10 to 15 minutes before riding. UK examples are Muc-Off Dry Chain Lube and Finish Line Dry.
• Wax. For a clean, quiet chain in dry weather. It needs a fully degreased chain, KMC says never to mix wax with an oil-based lube, and hot-melt wax needs the chain off the bike. KMC GO WAX goes on a dry chain, one complete turn on the inside of the chain, with the excess left on, and it must dry fully before you ride. UK examples are KMC GO WAX drip, or hot-melt wax as described by road.cc.
• All-weather lube. For mixed weeks when you do not want to switch. It costs more per bottle and goes on like a wet lube. The UK example is Muc-Off Hydrodynamic, rated by Muc-Off for up to 200 miles.

Whatever you choose, the lube goes on the rollers of a clean, dry chain, and the excess comes off. Finish Line's wet lube instructions say to reapply after extreme wet weather, every 100 to 250 miles, and whenever the drivetrain gets noisy.

How often to lube a bike chain

Lube the chain when it squeaks or the rag test finds it dry, and on a schedule in between:

• Cycling UK suggests every 160 km on the road and once a month for occasional riders.
• Canyon puts a commuter's clean and lube at about once a week.
• KMC's care page says after 100 km at the latest for all-weather riders.

In a London winter, a drop of wet lube after each soaking ride plus a full clean at the weekend keeps the chain silver until spring.