I recently upgraded my rims to some Velocity B43s and since the switch I've had my cog come loose a few times. I'm riding the Origin8 TorqLite 17t cog right now with my original lockring from my first rims that come standard on the Langster, pretty sure they were some AlexRims or something like that. The slip doesn't happen all the time, just every once in a while when I'm backpedaling to come to a stop, not even when I skid. I cranked both down as tight as I could get them but it still happens now and then. Anyone ever had this prob? I just ordered a new cog and 2 new lockrings to try out (an Origin8 and a Shimano) so hopefully the combo of the new cog and lockring works, but if anyone has ever had this prob and has any advice or fixes I'm definitely down to hear them. Thanks.