Some flip flop hubs are fixed/fixed, you didn't specify fixed/free.
You said 2 cogs on one hub, you could've meant both on one side.
Really, your question wasn't very well placed, hence the lack of a decent answer.
Now we're more clear, yes you can run one with a BB lockring on one side, but not advisable brakeless. I ran like this on the track and it was fine. If riding the street you may want some high strength loctite as well...
Some flip flop hubs are fixed/fixed, you didn't specify fixed/free.
You said 2 cogs on one hub, you could've meant both on one side.
Really, your question wasn't very well placed, hence the lack of a decent answer.
Now we're more clear, yes you can run one with a BB lockring on one side, but not advisable brakeless. I ran like this on the track and it was fine. If riding the street you may want some high strength loctite as well...