45-60g carbs/hr on the bike and at least 30g post-ride, preferably with protein. Makes a huge difference, especially when I'm at the upper end of that band.
Quite often you have to eat more than you think you need, and it doesn't always feel normal, but you get used to it. You've got to think, even at 60g, that's only 240 calories/hr. If you're cracking on with your riding, you might be burning 700-800 calories per hour!