I bought a entry level single speed with a flip flop hub for commuting. It only came with a fixed cog (non-free freewheel). The first time I rode it in traffic, I had to scurry through an intersection so I stood up out of the saddle and pounded on the pedals.
Terrifyingly, the cranks "slipped" and I didn't get any acceleration and had to coast through the intersection. In other word, my lead foot/crank/pedal drops from the 1 o'clock position to the 6 o'clock position at high torque loads.
The pedals are securely screwed into the cranks.
The cranks are securely bolted onto the 46T up front.
The chain didn't jump the front gear.
The chain didn't jump the rear fixed 15T gear.
What's left to "slip" and how do I stop this from ever happening again?
Here's the bouncing chain. I think it's related: