Different brands of wheels have different hub heights. Hubs of the same brand and model of wheels also have different heights due to materials and molds during the production process. Using a spacer measuring tool to measure the hub height can better match the flying saucer and allow the bearings to perform better.
Impact of spacer mismatch?
The spacer is too short and cannot support the inner ring of the bearing, affecting the rotation speed. The spacers is too long, causing abnormal noise and even severe wear and tear on the bearings.
