Depends on how dirty your chain is. Cleaning isn't necessary if the chain isn't really dirty. It's still better to lube onto a dirty chain than to not do anything at all though. Kerosene works well as a cheap cleaner.This might be a dumb question, but do you have to clean your chain before you lube it? or does it not matter? Also, I've ordered the PJ1 Blue Label chain lube, any suggestions on a cleaner?