Almost new chain, proper adjustment. One link has simply fractured across the side plates. Bike is stranded. Son came to fetch me after I got a lift to work. I shall have to go back and fetch it next week when I have finished work this week. Buggeration. I had just got this job too, after 3 years of virtually no work. How often do chain sbreak? This is only the second one I have ever heard of. DID chain it was too. At least it got spat out the back and it only broke three spokes on the way and didn't get wrapped up.