I am intrigued by the high carb during riding thing and tried it for the first time this weekend. I always focused on calories / hour and never really look at carbs.
For yesterday, planned 3-4 hour road ride, starting at 4:45am (so no food since 9 pm):
Gel, 23 grams: start of ride
Chewy Granola Bar: 17 grams
24 oz bottle, 75 grams (tailwind)
Half a pack of Gu Energy Chews, 22 grams
24 oz bottle, 75 grams
20oz bottle with just water
212 grams today.
Ended up being a 3.5 hour moderate pace. Maybe a bit higher than my endurance pace with 4,200 feet of climbing.
I forced drinking the bottles 1.5 hours each. The chewy bar was an oddball and I choked it down at 45 min. I could have done the second half of the Gu chews around 2:45 but felt I didn't need it.
Since I go all by perceived effort, and was at 60 grams / hour, which is more than double my norm, I will say I felt more fresh in the last hour, also being that this is an hour - 1.5 longer than my average length ride. In any case, I think value will show more when the intensity goes up.