Originally Posted by DrIsotope

2400 feet of climbing over 75 miles is practically flat. So long as the weather is hospitable and you are conscious about your pacing, you should do fine. My wife works too much, and only gets to ride maybe 40-50 miles in a typical week, but still manages to do a 70-80 mile group ride a few times a year. I (apparently) ride far too many miles to offer any helpful advice-- I did 67 miles with 2650ft^ @ 17.5mph this morning on 40oz of water and half a PB&J. I'll do another 50+ tomorrow.