Shortly after I started home (13m) the saddle mount on the seat post failed. It is a single boltstyle and the bolt failed. It fell in the grass along the bike path and was lost forever. I searched for about 15min. Unfortunately it took the top half the clamp with it. So the spare bolt I carry was useless.
Riding the full 13m while standing was quite a workout.
LBS had a spare clamp that fit so all is well. I thought I was covered by carrying a spare bolt, but Murphy never sleeps.