To keep your drivetrain in tip-top condition it's recommended that you lube it properly. First step though is to thoroughly degrease your drivetrain, and here's how you do it.
1. Clean your bike
Wash your bike thoroughly.
After hosing the worst of the mud off, use a bike cleaning spray to loosen the grime and dirt before gently scrubbing with a soft brush.
Make sure to thoroughly rinse the bike spray off the paintwork.
2. Degrease the drivetrain
Spray degreaser (also known as ‘chain cleaner’ or ‘drivetrain cleaner’) liberally all over the cassette, chain and chainrings while back-pedalling the chain.
Leave it to soak in for a few minutes.
3. Scrub the chain clean
If you have one, use a chain cleaning tool to scrub the chain clean.
Otherwise, use a stiff brush (or old toothbrush) to get in among the chain links, chainrings, jockey wheels and cassette sprockets.
4. Wash off the degreaser
Wash the degreaser off with a hose while back-pedalling the chain.
Avoid spraying water directly into the bottom bracket or freehub body (high-pressure jets can damage the bearings) but target the cassette, chainrings and chain.
5. Clean off the chain
Use an old rag or paper towel to wipe any remaining grime off the transmission, along with the worst of the water.
Hold a thick section of rag around the chain while back-pedalling.
Repeat with clean sections of the rag until the chain runs through clean.
6. Re-lube the chain
Use a quality chain lubricant to re-lube the chain before it has time to corrode after its wash.
Apply the lube liberally while back-pedalling rapidly, then wipe off the excess with a clean rag.
7. Coat the chain lube evenly
Back-pedal while pinching the chain inside a short section of rag.
The aim is to coat the chain evenly with lube while getting rid of any excess, but not to completely remove all the lube you just applied.
Wet vs. dry lube
Wet lube is thicker, so it sticks for longer and is less likely to be washed off on rainy rides, but can get dust and debris stuck to it.
Dry lube is thinner and less likely to gunk up your drivetrain but needs to be reapplied more often.