Ok, here is a pic of my derallieur this morning. The chain and rear cassette were replaced new last week. Since then there has been an annoying click click click as i pedal. This noise only occurs when pedalling, not when free wheeling and only when I am on the bike, not when turning the pedals by hand when off the bike. I put up with it for a couple of rides until today when the chain fell off when I went over a small bump (which has never ever happened to me before). So i am thinking the perhaps the chain is too 'loose'...or has perhpas 'stretched in' ??? Should I have a bigger gap between positions A and B in the photo? Perhaps by pulling the arm down in the direction marked as C/D in the pics??? Is this a cable tightening job?? I lubed the crank arms because last time this click occurred it was them but it hasnt solved this one...which sounds more like the chain to me. I took a look at the bicycle tutor tutorial video on this and I am wondering if the derallieur is set right on mine...as i have a degree in incompetency I am loathe to mess with this just before my tour but i need to get rid of the click and stop the chain falling off...so any suggestions welcomed and appreciate as always. Ta.