hey everyone-
so i'm pretty new to fixed gear bikes and im still learning how everything works and these forums are great.

i've been having a problem with my fixed gear though that i'm hoping some of you can help me with. it happened first when i was doing a skid stop. i locked the cranks and began the skid but then all of a sudden i lost tension and the cranks rotated about 45 degrees before locking in again. it felt like maybe the cog slipped or something. now it happens a lot, like if i stand up to get the bike moving from a stop the gear will slip and the cranks will quickly drop about 45 degrees. whats the problem here and how can i fix it?