Left home 7.30 Friday for my ride to Murray Bridge. Bike serviced on Thursday and new chain. Chain came off the large crank 2 or 3 times in the lower stretches of Gorge Rd then got worse as the climb got steeper and came off the lower crank as well. Not happy but figured it would improve once I was over the worst of the climb. 30 mt before I got to Kangaroo Creek Resevoir I came to a sudden stop. For some reason the rear derailleur had dragged into the wheel. Managed to pull derailleur out from wheel and sat on the roadside and waited for Lyn to pick me up. Very lucky that I wasn't going downhill when this happened. Back to the bike shop this week but I'd be interested in any theories as to why the derailleur would drag into the wheel like that when I'm grinding up a hill at about 7km.