have a problem with the alignment/centering of ultegra brakes on an aegis aro svelte i just purchased. when applying the brakes they actually seem to move the rim over a small amount (perhaps a 1/32") versus centering. i have tried to recenter the brake assembly by loosing the brake/frame attachment bolt but still can't seem to get the results i am looking for. i noticed on the left arm there is a small allen bolt adjustment facing upwards. is this for centering purposes? oh and the wheels are perfectly dished. thanks for any input.