I have those pedals (Shimano 600s) on all three fix gears. Best fix gear pedal I have ever used. (With a straight forward modification), easy to pick up in traffic starts, very reliable in all weather and have toestraps and a rattrap for traditional style cleats - IMO the best, safest fix gear pedals by far. (I like going downhill fast. Un-cleating and having my foot separate from a 200 RPM pedal driven via gear reduction by all of my inertia is a nightmare I never want to see play out. I also kmow at 200 RPM I have no idea of what angle my foot is at and no way am I looking down to see.)

I do ride clipless on my two geared bikes - black LOOK cleats on one and SPDs (for good winter boots and off road) on the other. Maybe I should take that LOOK bike to 600s. Would simplify my shoe collection.

Ahhh! Old thread I've already answered. Forgive me.

Ben