Originally Posted by
soyboy
i really don't see the point even for multiple brakes on one wheel, if you were controlling a disc or drum and then something on the rim it wouldn't make sense to pull them with the same pressure
As John pointed out, tandems do this all the time, in addition to the standard front and rear brake, they often have a drum brake in the rear. The drum brakes doesn't stop the bike so much as prevent it from going to fast in the first place.