I've trolled these forums off and on for about a year but I've never really had the urge to post before now. A couple of comments in other threads regarding clipless/cages did not sit entirely well with me, so I've decided to pick this fight.
I've owned my fixed bike for about year now. It has been my primary form of daily transportation during that time, except for in October (car hit me, took some time off), and January through March (weather).
When I bought this bike, I paid extra to get the clipless pedals instead of the "regular" ones. I also bought a pair of Shimano DX (that's what it says on them...) shoes to go with the pedals.
I never clip in.
I still wear the shoes. They don't look too ridiculous and the laces are nicely hidden under a velcroed flap. They let me do a nice little tap dance thing at work, too. However, when riding my bike, I use the "normal" side and not the clip side.
When the bike was relatively new, I did use the clips. I practiced engaging and disengaging and all that. I had one ugly spill because I didn't disengage my foot properly. That really hurt. Over time, I came to see them more as a nuisance than any sort of advantage. Over time, I gave up using them.
Why should I clip in?
I've only ever had my feet thrown from the pedals once. It was when the bike was new and I was going down a hill - I was not ready for having to pedal that fast. It has not happened since.
I lied above when I said a car hit me. I actually hit the car. He failed to yield to traffic (me) and took off from his stop sign right in front of me. I hit his right rear quarter-panel doing maybe 20-25 km/h. My bike bounced back while I flew over his trunk, landing in a roll on my shoulder and back. I was barely hurt, though perhaps more than slightly surprised. He got a $90 fine for it. Take THAT, creepy driver guy!
What would have happened if I had been clipped in? Would I have had my upper body whipped forward? Would I have somehow pulled the bike over the car with me? None of the physical scenarios I can think of sound as appealing as what actually happened when I was not anchored to my bike.
I accept the fact that I have only my own experience from which to draw conclusions, and that there are riders out there (and on here) who have more experience than me by far. So, what am I missing?
Why should I clip in?