I purchased these bearings for my daughter's upcoming competition based on reviews. She skated on these bearings twice when I noticed that one wheel would only spin about 1/2 rotation, stop, and spin slightly in the reverse direction. I removed the bearings and cleaned them according to the manufacturer's directions. After reinstalling the bearings, there was no improvement. I have emailed Bones twice directly with no response. My daughter was unable to use these new, expensive bearings in her latest competition. I am thoroughly disappointed with this purchase.