RC Ball bearings should always be your first upgrades, it reduces friction for less rolling resistance, and that means higher speed and longer the running times. RC Ball bearings hardly require maintenance and last a lot longer than stock Oilite bushings.
Yeah Racing RC Ball Bearings have the lowest resistance. They are manufactured by Aircraft quality stainless steel. Pre-lubricated with light protection oil (not grease) to ensure its excellent performance!
These high quality bearings outweigh the other low quality one:
Aircraft quality material
Yeah Racing (#YB6014CMS/10) RC Ceramic Bearing (5x11x4mm)/li>