Riding home from work last night and I notice an unusual "clunking" noise happening periodically from underneath the bike, usually when I was going over a bump etc. Cut a long story short, when I got home I wanted to lube the chain, popped the bike up on the centre stand and notice that the chain is as loose as anything...a good 3-4 inches of play, I am like WTF, how does the chain become so loose so quickly :-k Out come the tools and I tension the chain, first time I have ever done it but it it is a relatively simple task. I tension the chain to the manuals specs, I then start the bike and kick it in to gear and let the back wheel turn for a minute on the centre stand, turn the bike off and the chain is now over tensioned - is this normal ? I back the tension off a little and repeat the process, chain is now too loose, repeat the process, this time the tension seems fine. Whilst I am running the bike I notice the chain being a little "jumpy" and hear some noise coming from the area of the front sprocket. I haven't pulled the bike apart to have a look, will prolly take it for a short ride tonight to see what is happening, but for those that are mechanically minded I have a couple of Q's. How could the chain become so loose so quickly? Is it normal that after tensioning the chain to the manual specs, is it common for the chain to be over tensioned after running the baike for a short time? After seeing how looses the chain became, and between the chain being twitchy and hearing some noise, is it possible for the front sprocket to throw a tooth or 2 or is it something else? I think that this may be beyond my (very limited) spanner skills, I may have to take it into the shop.