A short primer on chain lubes
Keeping your drivetrain clean and properly lubricated not only ensures optimum mechanical operation of your bike, but also extends the longevity of the components of your drivetrain that suffer wear from friction.
Bicycle chain lube comes in different varieties for different uses and riding conditions, and the process of finding the right one for the type of riding you do can be a little confusing. Most chain lubes have a chemical formulation to optimally perform in certain riding conditions, and this each kind of chain lube comes with its specific advantages and drawbacks.
To minimize the metal-on-metal friction that results in accelerated drivetrain wear, chain lube coats the chain with a thin layer of oil and other chemical additives. INot only is it important to use the right lube for the conditions you frequently ride in, but also to know when and how to apply it in order for the chain lube to do the job it is made for.
The accumulation of dirt and grit on your drivetrain will prevent the lube from doing its job properly, so always try to first ensure that your drivetrain components are clean enough before you apply lube.
If you often ride in wet conditions, clean and lubricate your chain immediately after finishing your ride to prevent rust from setting in and accelerating wear on your drivetrain parts. Otherwise, under normal riding conditions how often you should lubricate your chain depends on the type of lubricant you use and manufacturer recommendations. Reading the instructions on the bottle of lube is helpful!
One way to know your drivetrain needs reapplication of lubricant is the noise it makes. A noisy bicycle drivetrain is usually a sign of trouble, because in many situations more noise = more friction.
Assuming your gears are properly adjusted, excessive noise from your drivetrain as you ride means that it is time to give those gears and chain a quick clean and lube.
One thing to keep in mind is that overapplication of lube can be just as bad to your drivetrain as lack of lubrication. Too much lube makes your drivetrain pickup more dirt and grime. This is more often the case if you use more viscous lubes designed for wet weather riding. Conversely, dry lubes pick up less dirt, but the downside is that they need to be applied more frequently.
Many other types of chain lubes combine characteristics of wet and dry lubes. There are wax-based lubes and graphite infused lubes. Some riders even painstakingly go through the process of super-cleaning their chains, then dipping them in homemade baths of molten paraffin wax.
To lubricate the chain, shift into one of the middle cassette cogs, then turn the crank backwards while using a drop nozzle of your lube bottle over the inner side of the chain. For most types of lube, one drop per chain roller is adequate (but again, different lubes will have different application methods as recommended by their manufacturers). Give the lube a little time to get into the crevices between the links and rollers of the chain. Give the chain a quick wipe to remove any excess, then your bike is ready for the next ride!