if youve never repacked your bearings, its always a good idea to mix it into the maintenance. but, i would think with what your discribing... this isnt bearings <img src="/forums/images/graemlins/confused.gif" alt="" />, i would think that it would get louder with speed and more noticable? im thinking something with the breaks... have you been wheeling lately? if so, check behind the rotor guard for little pebbles that will occasionally slip down and wedge inbetween the rotor and pads. it happens to me all the time <img src="/forums/images/graemlins/angry.gif" alt="" />. also, check the boots on the caliper pistons. once those are compromised your pistons will start to stick and cause a grinding noise. btw, is the noise coming from both sides and what do your rotors look like?