We use these bearings with great success in antique harley race bikes on the crank main shafts replacing the stacked- cageless roller bearings. These bearings work great for cases that have a less than perfect line bore tolerances. And these are nylon cages that hold in the bearings so if one comes to you with a bearing displaced just put it back in place and it will be fine. I pull them out for a thorough cleaning if need be. They usually come out during rough treatment in shipping.