Indeed - before I figured that out I had a couple of incidents of post-ride vomiting from drinking only water, now I know to be careful of that but cramping does still happen if I get lazy about spiking my water with electrolyte tabs. OP's reported water consumption seems a little low for that but I guess everyone is different.

I also typically have at least one foil packet of oral rehydration salts in my first aid kit - formulation may not be ideal but seems an improvement over water in a post-bonk or long train ride back situations where I've come to realize pure water is effectively all but toxic.

Thanks for the reminder that I need to go back to doing this. I've been being lazy and just buying it in liquid form since where I ride I typically have to pay for water anyway. But that leads to needing to make decisions between water and sports drink purchase or both, wheras what I prefer to to do is buy a 3 liter or gallon water bottle (typically the cheapest almost without regard to quantity) to refill everything, wash out my headsweats, soak my sunsleeves and wash my face. Packing baggies of drink mix would let me get both from one water source, especially the town recreation complex sink I survived filling a bottle from this week.

On really hot days I'll even put an electrolyte tablet in sports drink.

Ironically was fine on my longest ever ride this week, but a week previous about 36 miles into a 49-miler, behind schedule on a 93F afternoon took a spill and ended up sitting on my rear on the trail with my legs completely and utterly locked both ways in cramps, unable to get up as doing so would require shortening one of the complaining muscles. Someone passing the other way was nice enough to wait until I'd managed to finish moaning and got my legs under me. Ended up walking about a quarter of a mile to stretch out, downed some more electrolyte mix, got back on and pedaled slowly for the next mile to a planned rest break, concentrating on stretching muscles.

I've been wondering about how much pre-ride matters and over what period. I'll often get four bananas from my corner fruit stand the night before, eat one immediately, one in the morning and then see how far up the trail I can get the remaining two before they turn to mush. Should I be starting in on them longer in advance of the ride?

Related, say one gets 5 miles into the ride and realizes that the bag of food and tube of electrolyte tablets are still on the kitchen table. Typical pharmacy/ convenience store coming up, so bars and sports drinks are easy, but what general market consumer supplement substitutes for electrolyte tablets? Ended up wandering up and down the aisles for a bit, finally just rode off pinning my hopes on the bike store 2/3 of the way through the trip - which fortunately was open, and did have Nuun tabs.