I do all my summer riding in Teva sandals, but I also wear them all the time so my feet are used to them. For months I don't wear socks and shoes at all, unless I have to go to a funeral, or do something that really requires steel toe boots. Last summer was my longest run yet, 117 miles in a day pulling a trailer with a light canoe and all of my camping stuff, and my feet weren't sore though I was pretty worn out in general at the end of the day.