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.