Originally Posted by
sweeks
Some direct-pull brakes contain bushings that serve as pivots for the brake arms. The bushings are tightly bound by the arm mounting bolts and do not rotate, so lubrication is not necessary. I just installed a set of Shimano Deore brakes that are made this way. (I still grease the pivot posts to prevent rust.)
These brake arms don't rotate directly on the frame's pivot posts.
Uh, are you sure about that? You may be right. But my recall on my brakes was that the sintered (and possibly PTFE impregnated) bronze bushing, is a press-fit into the arms, and is a close-slip-fit and pivots on the steel brake post. As I result, I grease well there. If the arm itself pivoted around the bushing, you would have a sliding interface between bronze and aluminum, and that is usually not the case, as aluminum is too soft. I thought the big bolts into the steel brake posts, the head bottoms on the outer rim of the post, and the bushing is a tad shorter than that, so is not clamped. But my memory could be wrong, or my cheap Promax and Tektro V-brakes are different than your Deores.