Originally Posted by
timcupery
I don't see any downside to having a rear brake on a fixie, besides a little weight and a little less simplicity.
Well then there you have it.
Edit: Yes, you will have rattling. Not necessarily th levers themselves, but the mechanism that holds the end of the cable will be able to rattle around in there. I suppose you could take it out or glue it or something, but that's just silly.