Only way to stop would be to bail. And if you were going fast downhill that would hurt really bad. I don’t know to much about that sort of thing but I think it would be really hard to put breaks on a bc.
make a brake that you hold 
It would work with a break, but every bump you hit can stop you, and there’s no way to get going again (except, starting youth your hand, but still…). But, if my memory doesn’t deceive me, I think it’s been done before
i do muni bc a little bit, and i succeed in slow down by rubbing the wheel against my leg (with my tibia protectors !!) it heats up if you keep on, but it’s the only way i found to control more or less the speed
hoping you understood …
evan byrne or spencer hochberg put a disc brake on a BC, its freaking pimp, search the gallery a little and i’m sure you could come up with the pictures i’m thinking of.
and both spencer and evan agree that brakes don’t work for BC wheels. just get an ace wrap or an old piece of tire, and put it on your leg, that works fine for braking on a BC.
What for BC must you have for street bc riding?
A trial wheelset with a shaved tire and a 14mm hub or a Nimbus bc wheel with maxxis hookworm?
Plz answer
Sorry for my bad English