Enduro Bearings 61903 LLB – 17x30x7

″Enduro Bearings 61903 SRS – 17x30x7

THE SEALS are ″″SRS″″ (Snap Ring Seals) or ″″LLB″″ (light contact, dual-lipped labyrinth). Both are effective at sealing while keeping drag to a minium. The SRS sealing mechanism is called an axial face seal design. Different from most seals which seal perpendicular to the mating surface, these seal in a parallel configuration, where the inner flat part of the sealing lip mates up against a machined metal “shelf “ on the inner race of the bearing. Water and foreign matter force the seal closed when trying to enter, while, under normal conditions, the bearing rolls along with extremely low resistance. The LLB sealing mechanism is a low contact labyrinth type, with 2 sealing lips which fit into a matching groove on the inner race. The outer sealing lip repels dirt and water while the inner sealing lip retains the grease. When the bearing is first turned, you will notice some grease will come out of the seals. This fills the chamber between these 2 sealing lips, forming a “hydromatic seal.”″