I've only stacked it once, about two weeks after I first started using SPDs - was turning off the road onto a shared use piece of pavement, going about 1mph and some woman on a boris bike came at me. I had to brake sharply and put my foot down, except I couldn't unclip in time - cue the slow-motion topple and roll. These days I unclip one foot well before I turn off!
I've only stacked it once, about two weeks after I first started using SPDs - was turning off the road onto a shared use piece of pavement, going about 1mph and some woman on a boris bike came at me. I had to brake sharply and put my foot down, except I couldn't unclip in time - cue the slow-motion topple and roll. These days I unclip one foot well before I turn off!