CeramicSpeed Bearing 61903 6903 coated 17x30x7mm

61903 (6903) coated bearing - inner diameter 17mm/outer diameter 30mm/thickness 7mm Suitable for all disciplines. Advantages over standard bearings: Low friction, longer life and better power transfer. Ultra smooth silicon nitride balls combined with ultra smooth polished hardened steel grooves. Metallic layer 75% harder than hardened steel. Applied very thinly and evenly over the entire inner and outer surface Seals prevent the penetration of dirt and moisture CS balls 400% smoother, 128% harder and 58% lighter than standard steel bearings