Yeah I mean it seems like it was a reasonable progression from what I've been doing. I've done these two climbs in tandem before, twice in the preceding three weeks. The only difference yesterday (up to the time of the bonk) was the relatively easy miles 17 miles/ 700 ft I rode out to start those climbs. Thanks for the feedback, I can definitely try to be more mindful of how I pace the hydration. I just finally made the switch from camelbak to bottles recently, still getting used to it.