Answer
There could be a couple of reasons. the first could be you have an unbalanced tire or the tire could have a broken belt on it. the second could be alignment. the third could be in you steering arm, ball joints, etc. and one final reason could be maybe you have a rotor thaty need s to be turned from running too long on bad brakes etc. so without driving or actually looking at it that would be my best troubleshooting advise for ya. lemme know what it turns ut to be if ya could.