This is what I do. I go by time references not distance, it depends to me on length of ride not distance. If ride is going to be under two hours I taken two water bottles, I always take two water bottles as you just never know. For a ride I know will be over three hours I start my nutrition routine at 45 minutes when I will start with electrolyte tabs every 45 minutes, at 60 minutes I start gel and food intake. For me that's a shot of gel or a few honey stinger chews or half a granola bar or whatever food I brought. If its a hard group training ride I will always add extra calorie intake if we stop for a nature break. For me though its always water intake, you have to stay on top of water intake. For a 60k ride I would likly just take two bottles and a granola bar unless I planned on pushing real hard then I would take my electrolyte tabs and maybe some gel type calories.