When I switched from running to biking I was a little curious about the water bottle thing also. I used to run 6 days a week (7-14 mi /day) and never took along water even on 90+ degree days. Only on runs longer than 15 mi (approaching 2 hrs) would I ever plan a water stop along the way. But I've also noticed that climbing a long hill on a bike seems to burn a lot more than I remember when running. IMHO there's more pain in biking than running.

dbg