These are rubber sealed ball bearings, which offer smooth rotation, great precision of attachment and even simplified maintenance.
• 730 (3x7mm) Sealed Ball Bearings x2
• Applications include M-chassis gearbox area.
• Using ball bearings in place of plastic and metal bearings gives more efficient rotation and better parts setup.
• These ball bearings employ blue rubber seals rather than metal ones – this allows you to open up the bearings to clean and work on them. Blue rubber seals also vastly help in the prevention of debris entering the race roller.
• Low-viscosity oil is used to lubricate the internal workings.
• Periodically perform maintenance such as adding oil; after crashes, checking bearing movement is recommended.