<2 hrs: No food on the bike. (plenty of water)

>2hrs: 100-300 calories on the bike per hour. The longer your ride, the more important it is what you took in 1-2 hours ago. So that means while <2hr rides don't need any extra calories on-ride, for these longer rides, if you don't take calories in your first 2 hrs, you'll probably pay for it at hour 4+, so I start taking in calories in hour one on longer rides.

I use maltodextrin, bought in bulk, in my water bottles.

You can also use gels (take more than one if you need), or even food, but if you want to keep rolling and not stop, liquid nutrition rules.