One year,we did a ride in Death Valley..In March...The bike organizers said...Even when you sleep..During those eight hours..You have dehydrated about one quart of water...Doing nothing..just sleeping.....because it is so dry...
Another desert ride, in nearby Boreggo Springs...that is like early spring usually...60 plus some miles...w/o my hydrapak, My bike only carries three water bottles... at a liter an hour, that is one water bottle short..
after watching one friend bonk due to dehydration...I bought a hydrapak...and it really wasn't all that hot..watch out for dehydration....it creeps up on you...think you are ok and 15 minutes later, you bonk..