So i was riding my recent fixie conversion (fixed hub not bumbike) home today in the rain and was trying to do a little skip to check my speed coming up to a light and when i resisted the pedals there was suddenly no resistance. It was like the hub suddenly became a freewheel... i don't know what could've caused this and tried another skid once i'd turned onto a side street and the same thing happened. I tried another skid when i was just outside my house and it worked... i'm very confused.

This reminded me that in the first few days of riding my fixed a couple of time i would stand up to pedal from a stop and the pedals would slip in the same manner (which i chalked up to wheel slip and so didn't worry about). All of these were silent however so i think that rules out the wheel slipping, and it has happened when both pedaling forward and resisting the pedals.

WHAT COULD THIS BE... HUB... BB? I'm not sure where to start. I was considering going brakeless but this has me rethinking this!!! Any suggestions would help and be GREATLY appreciated!!!! Let me know if there's important information i might have left out as well cause i'm somewhat ignorant of the functioning of hubs and bbs.