Originally Posted by
mack_turtle
that's not really true. set the height of the yoke first, then adjust the spring tension so that the arms are evenly spaced from the rim. then adjust the position of the pads so that they are closer to the rim. you might get more power out of the brake if the pads are spaced further from the brake arm instead of butted up against the arm. you have about and inch to work with and it looks like yours are mashed all the way in against the arm. experiment with that distance.
Look closer at his brakes. The straddle-cable isn't adjustable. If he lowered his yoke by sliding them down the main brake-cable, his calipers will be fully spread open by 2-3" and there's absolutely zero way he can close them by squeezing the levers or adjusting the pads. Sliding the posts out to move the pads will just have them aim higher and higher upwards, but they won't be any closer to the rim.
He needs to get a shorter double-ended straddle-cable first. And they're not a very common item at LBSes nowadays, but there are clamp-on barrel-ends you can get to finish off a single-ended cable.