Just when the bike seemed to be going really well (I should have known better) it decided to play up in the middle of nowhere high in the Pentlands. First of all a spoke in the rear wheel broke and snagged the chain bringing my progress to an abrupt halt. I managed to get this unsnagged and got underway again for about a hundred yards when a hideous scraping noise started. the bike was turned upside down again and eventually after removing the rear wheel I discovered the spring holding the brake pads had somehow managed to come out at one end and rub against the disc. I managed to free this off slightly and continued on my way to the accompaniment of much scraping and screeching which eventually got quieter as the spring wore away!
I managed a rather noisy 18 miles in the end and tomorrow night's going to be repair night!