[Sailariel]

That depends on the type of riding you do.
Always after riding in the rain
At least weekly if you ride in dusty conditions
After washing the bike


What I generally do is on a weekly basis, I put the bike up on the Pit Bull, wet a rag in kerosene (Never use gasoline), and wipe the chain down while spinning the rear wheel by hand. Wipe with a dry rag and sit down and enjoy a beer or a coke. After about 15 minutes, I lube with Maxxima Chain Wax. Everybody has their own way maintaining a chain and there is no way that is better than the other. My personal preference is a clean chain.