Park Tool PPL-1 Polylube is a poly-urea based lubricant developed specifically for bicycle maintenance and repair. Polylube 1000 has an extremely high shear strength to protect vital parts under extreme conditions. Polylube 1000 also repels moisture and is compatible with conventional greases. This grease is safe for elastomer forks and hydraulic shock seals. Polyurea greases are considered excellent bearing greases. The National Lubricating Grease Institute states in their guide, "Polyurea greases are widely recognized as on the best ball bearing greases available."