CeramicSpeed bearings are a great way to improve the overall efficiency of your ride. These bearings are nearly frictionless, improving power transfer and extending the bearing life three to five times compared to the industry standard. Silicon nitride balls are matched with hardened steel raceways for the smoothest possible function. This is the coated version which further reduces friction and increases durability. They are held in a reinforced polymer cage and optimized with CeramicSpeed grease. Special seals keep dirt and moisture out, maintaining like-new performance. When compared to other bearings in the industry, CeramicSpeed are 400% smoother, 128% harder and 58% lighter than the rest. Grab a CeramicSpeed bearing and improve your bikes function.