70 y.o. don't worry you've got plenty of time. The picture is of me and 2 guys, brother-in-laws, I met in Santa Maria CA. when I did a cross country in 2012. The guy on the right was 80 and the guy on the left was 88 y.o. and was looking for another bike because, as he put it, "I think I've got 10 more good years in me".