I've had a noise coming from the front end on my bike since I bought it. It doesn't sound catastrophic and its not really the normal loud grinding noise I would associate with failed bearings more a moan similar to tyre noise on a 4WD(not quite that loud though). Anyway I had the mechanics check it out, they lifted the front wheel off the ground and checked for play and spun it around listening for noise and gave it a clean bill of health. There was no noise. Yet the noise is present when riding. Could the bearings only be making noise when there is load on them? Probably should have them replaced anyway. Thoughts?