Latest update for those interested: My wheel is a Factory HD 16" single disc spoke wheel made for 1" sealed bearings. I installed 3/4" sealed bearings and spacer and the spacer is TOO SHORT. The reason, I believe, is because the bearing on the rotor side (left side) sits above of the hub surface on the 1" wheel (factory wheel w/1" bearings) and the bearing on the 3/4" wheel (factory wheel w/ 3/4" bearings) sits below the surface of the hub on the rotor side (left side). So, it's this difference that makes the 3/4" spacer too short. The spacer must contact both bearings. So unless someone makes a longer 3/4" spacer specifically for this change, you can't put 3/4" bearings in the 1" hub. When I bought this wheel, I thought I was buying a factory wheel made for 3/4" bearings but, when I received it I neglected to check it out closely until months later. That's when all the fun began! I noticed the bearing appeared to be high on the rotor side. After pulling the bearing, I found the wheel had no spacer at all. It also had a larger center hole, clearly for a larger spacer, which led to the differences between the two hubs and how the bearings seat. If anyone has any info pertaining to this change over, I'd like to hear it. Perhaps I'm missing something, it wouldn't be the first time! Thanks