I bonked Saturday about mile 55 into a 60 miler. Unfortunately, it was at the base of a 6%, 300 foot climb up to the plateau that I live on. I've bonked a few times, and I never feel it coming until it happens. I get the shivers, a huge stomach ache, and my heartrate never went over 140 during the climb, which went at a laborious 4mph. I usually go up that climb at about 12-13mph.