I have been working a lot on my on bike nutrition and hydration and recovery for swimming. I switch between tailwind and skratch for my liquid hydration.
@Silje - I have done 2 66 mile mountain bike races. They were point to point (no laps), so carrying food and water is something you need to plan. I only put water in my Camelback, so I eat 2 clif blocks an hour and drink water. I also carry salt and electrolyte tabs, since I sweat a lot of salts. I also carry real food- peanut butter and jelly pre cut up.
Based on the time and distance, for 3 + hour or longer rides, I use combination of real food and waffles, chews, something salty (cheese and crackers).
I break down my fluid to drinking something every 15 minutes. I know I should finish a bottle every hour or 75 minutes- broken down - my bottle should be empty every 4 to 5 drinks. If it isn’t, I finish it up and try to drink 20 to 25% of a bottle every time I drink. I also eat solid food every 45 minutes to an hour.
I have an iron stomach- and am known to eat the bacon drizzled in chocolate and maple syrup shots at events. I also try a lot of different hydration products, gu’s, clif bloks, sis gels, etc on zwift rides and my weekly long rides so I know what I can tolerate.