i just put together my fixy commuter with an IRO flip flop hub, soma cog and lockring (all purchased from IRO). I was going down a pedestrian overpass, and my lockring felt like it jumped a thread, because the cog unscrewed itself about a quarter turn. The cog pulled itself tight again when I hit flat ground, but i checked the lockring and it was a quarter turn or so loose. Does anyone know why this happens? Am I just applying too much pressure, or is the hub or lockring defective? I got all the parts brand new and rode it for the first time today. Any help would be greatly appreciated!