Went on a group ride out in the country to enjoy the fall colors, which are (already) at their height here in Minnesota. Twas to be a 70 mile ride, but 35 miles in (and therefore, at the farthest point from my car), my rare derailleur sheared off! Not sure exactly how it happened, but it may be that the chain jumped between the big cog and the chain guard and then pulled the derailleur around in a way that it just couldn't go. 35 miles out and the bike seemed to be dead..... One of the guys in the group had a chain tool and a lot of know-ow - he cut the chain, removed the derailleur, and set up the bike as a single speed. This was going to be a challenge because there were some good sized hills between me and my car, but at least it seemed workable. But, the chain tension was not quite right for any gear, so the chain kept skipping up gears as I was riding until it went taut, at which point pedalling was effectively impossible. This required stopping, removing the wheel from the dropouts, changing the gear to another cog, and then gingerly continuing on my way. Unfortunately, this happened about every half mile. By this time, the rest of the group was way ahead and I still had 30+ miles to go....so I backtracked to the nearest town, borrowed a yellow pages from a gas station, called a car service, and paid $40 for a ride back to my car. Kind of a disappointing end to what started as a great autumn day.