I thought I had a noisy rear CV and when I was replacing it, I noticed grease coming from the bearing. Replaced it, but that wasn't the problem. Yet, that is. It would most likely have failed at the most inopportune time, aka Cowspatoot on the Diamondback.
I had a front bearing on the 87 that was making noise but it was more pronounced when turning in a certain direction. I know the 88's are a bit different than the 87 but they still have a spindle, don't they? If they do, you can put a mechanic's stethoscope against the spindle and spin the wheel. The spindle doesn't move so you can hear any bearing noise.