FYI, if you had a road bike you were probably using SH-51 cleats, which only release by twisting the rear ankle laterally. There is another model, SH-56, which

FYI, if you had a road bike you were probably using SH-51 cleats, which only release by twisting the rear ankle laterally. There is another model, SH-56, which can be released in multiple directions, including by yanking straight up; it's primarily meant for mountain biking. If you're really concerned about unclipping, these might be better for you. Personally, I haven't had any problems with the SH-51 pedals, including city riding (in San Francisco). Part of it is psychological -- when riding slowly, particularly while splitting lanes, it's a little bit nerve racking to be clipped in at first -- but if you compare to toe clips, you'll probably find that you actually don't step off the pedals very frequently. The other aspect is that it's not completely natural to twist your ankle when falling (since normally you'd roll your ankle doing this!), but after a couple of falls or near-falls you'll get used to it and start to do it without thinking. Every once in a blue moon I'll have to stop extremely suddenly, or start to fall (e.g. misclip in while starting uphill), and I'll now turn my ankles without consciously thinking about it. With clipless you'll find that can actually unclip faster/more easily than toe clips since you can push forwards or sideways with your foot while falling, instead of being restricted to pulling back.