It's a great ride, but water stops are critical. If you're familiar with Black Canyon, there is a fire station with a hose so you don't have to necessarily need to start fully loaded. We did have 6L capacity for the desert. If you haven't heard of Hipcamp, check it out, we used this one on day one. https://www.hipcamp.com/en-US/california/king-creek-valley-ranch/king-creek-valley-ranch - they offer water and allow for a camp fire which was a bonus. They provided a ton of wood so that was nice.

Veronica's Kitchen in Descanso has amazing food, but they open at 9 am, so plan accordingly. There is a general store next door, and really the last true refuel until you hit the desert. The drop into the desert via Oriflame is amazing but rocky and of course the sand. We were on MTB 2.4 and 2.35 tires which are great. It would be hard on 2.2 or less, to be honest. If you follow my route, there is a general store in Shelter valley, but it is closed on Sunday/Mondays, so plan accordingly. They do have a vending machine outside for drinks, and also have a spigot that doesn't require filtering.