Quote Originally Posted by b_m1957
I've spoken to the garage ........ he's suggested checking the rear sprocket.
That simple statement shows the frightening level of his incompetence and lack of knowledge about bikes - pray tell me, how or what could the sprocket do to leave the chain really loose? : Whether the spindle nut is adequately or excessively tight, the chain will be loose because the adjusters have been messed with - probably slackened off to "allow" the chain to be removed from the sprocket by some eejit who shouldn't be allowed to work on a bike, and not correctly adjusted afterwards - probably a car "mechanic" who knows nothing about bikes at all >

What sort of tool were you using to try and undo the nut anyway Ben? You'd need either a large ring spanner or a socket and breaker bar, but NEVER NEVER NEVER an adjustable spanner, it's the bodger's favourite tool! :