Bearings are sold as a set – This set is (2) bearings
Onewheel Ceramic Hybrid Bearing – The 6907 Series (35mm X 55mm) Ceramic Hybrid Wheel/Axle bearings are produced with steel races and ceramic balls and have rubber seals to keep the elements out.
Burris Ceramic Hybrid Bearing (set of 2)
Reduced rolling resistance mainly results from the ceramic balls having increased smoothness, dimensional stability, and increased uniformity over their steel ball bearing counterparts. These properties ensure that the applied loads are more evenly distributed over all of the rolling elements. Additionally, ceramic materials have a much lower coefficient of friction (~20–30 times less) than steel ball bearings with standard seals and lubrication. This reduced friction results in less rolling resistance and faster rotational speeds.
Ceramic bearings are also harder than steel bearings and are therefore more durable. Studies have shown that ceramic hybrid bearings can last anywhere from 5 to 20 times longer. The smoother surface of the ceramic balls also significantly reduce the risk of bearing seizure with little to no lubrication. An additional benefit is their ability to operate in harsh environments due to corrosion resistance. Finally, their electrical insulation properties eliminate the risk of electrical erosion and pitting of the rolling elements.