Sounds to me like every club is different, and food may even be handled differently depending on the ride. I think the best plan for any brevet is to check with the organizer to find what food will be available on the route. In general though, whether riding on my own or with a group, I'm going to carry emergency food with me even if I expect to acquire food along the way. I like this site.
http://www.ultracycling.com/nutritio...portrides.html
600 calores and 60 grams of carb per hour for me
