BIKE CHAIN CLEANING AND MAINTENANCE
The chain and drivetrain are typically the dirtiest parts of your bike, and this dirt is bad news for bike longevity and performance. Specifically:
1.Increased rate of chain wear.
2.Reduced flexibility of chain links.
3.Added wear on derailleur assemblies and drivetrain cogs.
4.Impaired shifting performance.
Regular, On-Bike Cleanings
On a regular basis, look at the entire chain by standing to the side of your bike and lifting the rear wheel off the ground. Use your free hand to slowly rotate the closest pedal, inspecting individual chain links for dirt buildup, rust and/or tight links (links that do not bend easily as they pass through the rear derailleur). Check for adequate lubrication by listening for squeaks while riding. If you find either condition, your chain needs at least a spot-cleaning.
To spot-clean the chain while it's still on your bike:
Brush out the links with a firm brush (an old toothbrush also works).
Relubricate the links from time to time with a chain lubricant.
Wipe off excess lubricant with a clean, dry rag. Over-lubricating can actually attract new dirt.
For a more thorough cleaning, use a chain-cleaning tool. Attach it to your chain for a quick, deep cleaning.
Occasional Off-Bike Cleanings
Every few months or so (more often for mountain bikes), completely remove your chain using a chain-removal tool. Brush it well and completely immerse it in a chain solvent to get rid of built-up grime that brushing can't remove. Let the chain soak until most of the dirt has been freed from the links and bushings. Dry the entire chain using a clean rag. Make sure that the solvent has completely evaporated, then relubricate the chain and re-install.