I have a question here! I'm new to biking i wanna know what causes the drive chain of a bike to go loose? Some say its due to revving hard at lower gears! some say its due to taking too much load on the bike. I wanna know the truth and how can you prevent it from happening? I saw an FZ on the street and noticed that the chain's loose really loose... it was 'clinkin' is it bad for the engine?