These bearings are designed to accommodate slow movements such as those of frame pivots.They have more balls and are about 40% stronger than "traditional" technology bearings.Designed for frame pivots only, they should not be used on wheels, pedals, rollers, cranksets, etc.Every component (balls, rings and grease) is precision-manufactured and assembled.BlackBearing MAX bearings are 100% compatible with theorigine bearings on your mountain bike frames.