weather was fabulous today in chi town so i headed out. i managed 27.5 miles and felt great doing so and immediately after. however, an hour to two after the ride i was dead and crabby. i was totally zapped of energy. i have noticed this feeling before after my other 20 mile rides this month? am i bonking after the fact? i expect to be tired, but totally wiped out? background: pre ride meal was oatmeal, cliff bar, a coffee, and 40 oz water. during ride it was two polar bottles with diluted gatorade (half water/half gatorade) and two gels. post ride it was 2 cups pasta with meat sauce, cheese and crackers. also had some yogurt and popcorn later. the ride was 1 hr 40 mins. any ideas how to prevent the post ride bonk? later.