Clean and lube the chain

Put the bike in a work stand, or lean it against a wall with the drivetrain side facing you, so that you can turn the pedals backwards. Shift onto a middle chainring and a middle sprocket: the chain then runs straight and is easier to clean.

Tuck a folded rag between the rear rotor and the chain, or around the brake block on a rim-brake bike. Nothing you are about to spray may touch a braking surface.

Apply the Degreaser (or else Isopropyl alcohol) to the lower run of the chain while turning the pedals backwards, for two or three full turns. Leave it for two minutes: it dissolves the black grease packed between the rollers.

Then scrub the chain with the Brush (or else Clean rags), top, bottom and sides, while you keep turning the pedals. Work on the inside of the links, where grit wears the chain.

Rinse with clean water, using a sponge or a gentle hose, never a pressure washer, which drives the grease out of the bearings. Turn the pedals so that the whole chain goes under the water.

Then wipe every link by running the chain through a dry rag held tight in your hand, and leave it to dry for fifteen minutes. Lube applied to a wet chain does not stick and is gone within the first kilometre.

Put one drop of Chain lube on every roller, on the inner side of the chain, while slowly turning the pedals backwards. Start at the quick link, if there is one, so you know when you have gone all the way round.

Pick a dry lube for dry, dusty weather and a wet lube for rain and winter. Then turn the pedals for a minute and run through a few gears, so the lube works its way into the rollers.

Wait five minutes, then run the chain through a clean rag again. The useful lube is inside the rollers; whatever stays on the outside only collects dust and blackens the sprockets.

The chain should feel almost dry to the touch. Remove the rag protecting the brakes and check that not a single drop has reached the rotor or the rim.

A clean chain is the right moment to measure how far it has stretched. Drop the Chain checker (or else Steel ruler) onto the chain: if it sinks in fully on the 0.5 % side on an 11- or 12-speed drivetrain, or on the 0.75 % side on 10 speeds or fewer, the chain needs replacing.

A chain replaced in time protects the cassette and the chainrings; a chain worn too far wears them in turn, and then everything has to be replaced at once.