The Ball-bearing 5x12x4 Rubber Sealed Grease 2 produced by XRAY, is classified in
New high-speed ball-bearings produced specially for XRAY. ID x OD x depth (mm) = 5x12x4. Set of 2 pieces. Top-quality expert ball-bearings for a super-free, super-smooth drivetrain. These best quality ball-bearings are fitted with unique plastic covers, and are lightly filled up with unique grease for optimum smoothness, endurance, highest tolerance and optimum performance. These ball-bearings do have more (and bigger) balls within the cage than the regular ball-bearings, making them much more resilient under lots. The side covers are really easy to remove for easy and quick maintenance.
