Joint bearing / Spherical Plain Bearings (Fish-Eye Bearings) for Bicycles

Joint bearing / spherical plain bearings (fish-eye bearings) are mainly used in suspension mountain bikes, full-suspension bikes, and e-bikes, especially in suspension linkages, rear shock connections, swingarms, and pivot points. They are generally not used in road bikes or commuter bikes.

1. Main Applications

• Rear Suspension Linkages / Swingarm Pivots

Connect the main frame pivot, linkages, rear swingarm, and both ends of the rear shock absorber. Commonly used in full-suspension mountain bikes and e-MTBs.

• Shock Absorber (Rear Shock / Front Fork) Connection Ends

Joint bearings at the top and bottom of the rear shock connect the frame and swingarm. Some front fork designs also use joint bearings.

• Dropper Seatposts, Folding Joints, Special Drivetrain / Brake Mechanisms

Internal linkages of dropper seatposts, movable joints on folding frames, and some derailleur/brake rocker arms.

2. Core Functions

• Multi-directional articulation / angular displacement compensation:

Allows combined radial, axial, and oscillating motion to match angle changes during suspension travel without binding.

• Composite load capacity:

Simultaneously withstands radial loads (vertical), axial loads (horizontal), bending moments, and oscillating forces to handle off-road impacts.

• Low friction, high rigidity, and anti-eccentric load performance:

Spherical sliding structure with small clearance and high rigidity, suitable for high-impact, heavy-duty conditions.

• Maintenance-free / self-lubricating:

Engineering plastic joint bearings can run dry, resist mud, sand, and high-pressure washing, ideal for outdoor use.

3. Difference from Standard Bearings

Joint bearings act as universal joints for bicycle suspension systems, enabling flexible articulation during shock absorption while resisting off-road impacts.