How to Clean a Bike Drivetrain

Why a clean drivetrain is worth the twenty minutes

The chain, cassette, chainrings and derailleurs are the only parts of a bike that wear out in normal use. Everything else on a well-made bike will outlast you. The drivetrain will not, and how long it lasts is decided almost entirely by how much grit is in it.

Grit is the point worth understanding. Chain lubricant is sticky, so it collects road dust, brake dust and sand. That mixture behaves like a grinding paste, and it sits in exactly the places where metal moves against metal. A chain run dirty will wear out in a fraction of the life of the same chain run clean, and once the chain is worn past a certain point it starts wearing the cassette and chainrings with it. Twenty minutes of cleaning avoids a bill that runs into three figures on most modern bikes.

The second reason is that it makes the bike nicer to ride. A clean, freshly lubricated drivetrain shifts quietly and precisely. A neglected one graunches, skips under load, and slowly convinces its owner that the bike needs replacing when it needs an hour of attention.

What you actually need

The list is short and most of it lasts years.

• A degreaser. A dedicated bike degreaser is easiest, but any citrus or water-based degreaser works. Avoid petrol and avoid anything solvent-heavy on a bike with carbon parts or painted surfaces.
• A stiff brush. An old washing-up brush is fine. A cheap set of bike brushes is better because one of them will be narrow enough to get between the sprockets.
• A cassette cloth or a strip of old rag. Anything you can floss between the sprockets.
• Bike wash or a mild detergent, and a bucket of warm water.
• Chain lubricant, wet or dry (see below).
• A rag you do not mind ruining.

A chain-cleaning device, the little plastic box with brushes inside that clips over the chain, is optional. It is faster and less messy than doing it by hand and it does a decent job. It is not better than a brush and patience, just quicker.

What you do not need is a pressure washer. It will drive water and grit past the seals in your bottom bracket and hubs, which converts a twenty minute job into a bearing replacement. A hose on a gentle setting, or a watering can, is as much water pressure as a bike ever wants.

The order of work

Work from the dirtiest part outwards, so you are not cleaning the same surface twice.

1. Get the bike stable. A workstand is ideal. Without one, lean the bike against a wall with the drive side facing out, or turn it upside down on the saddle and bars if the bike has no bar-mounted computer or bell to crush.

2. Degrease the chain. Apply degreaser along the length of the chain while backpedalling, then leave it a minute to work. Do not skip the waiting. Degreaser needs time to break the old lubricant down and most people rinse it off before it has done anything.

3. Scrub the chain. Backpedal slowly with the brush held against the chain, top and bottom, then both sides. If you are using a chain cleaning box, clip it on, fill it, and backpedal for thirty seconds.

4. Do the cassette. Run your narrow brush between each pair of sprockets while turning the cranks. Then take a rag or a proper cassette cloth, hold it taut, and floss it between the sprockets to pull out the black paste that the brush left behind. This is the step people skip and it is the one that makes the visible difference.

5. Do the chainrings and jockey wheels. The two small wheels in the rear derailleur cage collect a ring of compacted filth that stops them turning freely. Scrape it off with the corner of a screwdriver or a brush handle.

6. Wash the rest of the bike. Bike wash or warm soapy water, brush, rinse gently. Work top down so the dirty water runs off surfaces you have already cleaned.

7. Dry it. A rag over the frame, then either leave it in the air for a while or take the bike for a short spin to sling the water out of places a rag will not reach. The chain must be properly dry before lubricant goes near it, because lubricant applied over water traps the water underneath and the chain rusts from the inside.

Lubricating, and the wet-versus-dry question

Once the chain is clean and dry, apply one drop of lubricant to each roller. Backpedal slowly and go link by link. It sounds tedious and takes about ninety seconds.

Then leave it for a few minutes, and wipe the outside of the chain thoroughly with a clean rag. This part is not optional. Lubricant does its work inside the rollers, where you cannot see it. Anything left on the outside of the chain does nothing except collect the grit that starts the whole cycle again. A correctly lubricated chain looks almost dry.

The choice between wet and dry lube is simpler than the marketing suggests:

• Wet lube is thicker, survives rain and lasts longer between applications, and attracts noticeably more dirt. Right for British winters, commuting, and anyone who rides in the wet regularly.
• Dry lube goes on thin, stays much cleaner, and washes off in the first serious downpour. Right for dry summer riding and for anyone who cares about keeping the bike clean.
• Wax, either drip-on or a full immersion system, runs cleanest of all and gives the longest chain life. It also demands the most preparation, because the chain has to be stripped completely bare before the first application.

Most riders in the UK are best served by wet lube from October to April and dry lube in the summer, and by not thinking about it any harder than that.

How often

There is no schedule that fits every rider, so use the state of the chain rather than the calendar. Run a clean rag along the bottom of the chain. If the rag comes away black, the chain wants cleaning. If it comes away grey, a wipe and a re-lube is enough.

In practice that tends to mean a full clean every few hundred miles for a summer road bike, and considerably more often for a bike ridden through a British winter, where a single wet week will strip the lubricant off completely. After any ride in the rain, at minimum wipe the chain down and put fresh lubricant on it before the bike goes back in the shed. That one habit does more for drivetrain life than anything else on this page.

The mistakes that cost money

• Pressure washing. Forces grit past bearing seals. The damage is invisible for months and then the bottom bracket is finished.
• Lubricating a dirty chain. Adds a fresh layer of oil on top of grinding paste. The chain gets quieter for a day and wears faster than before.
• Not wiping the excess off. The single most common error. Excess lubricant is a dirt magnet and contributes nothing.
• Degreasing a chain and leaving it bare. A stripped chain with no lubricant on it will develop surface rust overnight in a British shed.
• Degreaser in the bearings. Keep it off the jockey wheel centres, the bottom bracket and the hubs. It strips the grease that is meant to be in there.

What to check while you are down there

Cleaning puts your hands on the parts that wear, so it is the natural moment to look at them.

Check the chain for wear with a chain checker, a flat steel tool that costs very little and drops into the chain to show how far it has stretched. Replacing a chain at the right point is a small cost. Running it past that point wears the cassette to match, and then a new chain will skip on the old cassette and you have to replace both. Drivetrain wear is also the first thing an experienced buyer looks at, so it is worth understanding before you view anything on our used bikes listings. Our guide to what specs affect resale value covers why drivetrain condition shows up so clearly in what a bike is worth.

Look at the sprocket teeth. Healthy teeth are symmetrical. Worn ones curl over into a shark-fin shape. Look at the jockey wheels for side-to-side play, and at the chainrings for hooked teeth. If you are not sure what you are looking at, our groupset hierarchy guide explains how the parts are named and tiered.

If you are cleaning up a bike you are about to sell, do this first and photograph the drivetrain afterwards. A clean drivetrain in a listing photo tells a buyer the bike has been looked after, and it is one of the few things a photograph can honestly prove. When you are ready, our free valuation will tell you what similar bikes are fetching, and you can start your listing from there.

Common questions

How often should I clean my bike chain?

Use the chain rather than the calendar. Run a clean rag along it, and if the rag comes away black it needs cleaning. That tends to mean every few hundred miles in summer and much more often through a British winter. Always wipe and re-lube after a wet ride.

Can I use WD-40 on my bike chain?

Standard WD-40 is a water displacer and a light solvent, not a chain lubricant. It is useful for stripping an old chain before you lubricate it properly, but a chain left with only WD-40 on it will run dry and wear quickly. Use a proper wet or dry chain lubricant afterwards.

What is the difference between wet and dry chain lube?

Wet lube is thicker, stays put in rain and lasts longer between applications, but collects more dirt. Dry lube runs much cleaner but washes off in heavy rain. Most UK riders use wet lube through the winter and dry lube in summer.

Should I use a pressure washer on my bike?

No. Pressure washing drives water and grit past the seals in the bottom bracket, hubs and headset, which damages bearings that are expensive to replace. A gentle hose or a bucket and brush is all a bike needs.

Do I need to degrease the chain every time?

No. A full degrease is worth doing when the chain is visibly black and gritty. Between those cleans, wiping the chain with a clean rag and applying fresh lubricant is enough, and it is far quicker.