Some F1 wheels are slightly over-sized, or can become larger after a lot of runtime/board bashing. These sleeves are slightly over-sized to take up the slack in the front wheels. These replace the stock sleeves and use the same 1/8 x 5/16 flanged front bearings that come with kit. These are not needed on most CRC wheels, but are useful on Excelerate F1 front wheels.
