I've got a brand new set of these rims, however i feel bearing vibration from around 26-28 mph. The wheel is smooth as butter in hand, and up to about 25mph or so, but the vibration comes in very noticeable in that range, enough so that it will put my arms asleep. Its not a tire weight imbalance, the frequency of the vibration is certainly attributed to the wheel bearings. Could this just be a mis-adjusted bearing pre-load? I haven't messed with this yet.. Love the wheels but the vibration has got to go, wondering if there could be a problem with the ceramic bearings?? Any thoughts?