4pcs Dustproof Bike Bottom Bracket Covers

This set contains four high-quality bottom bracket bearing protection cup covers intended for use with 24mm-diameter bicycle crank axles. Each cover has dimensions of approx. 36.8 x 25 x 1.1 mm (1.4 x 0.98 x 0.04 inch), crafted from robust plastic material. The surface is smooth and tactile-friendly, offering resistance to corrosion and abrasion under regular cycling conditions. These covers act as a protective seal between the crank arm and bottom bracket, blocking dust, water, and fine particles from entering critical bearing zones. Installation is fully tool-free: just press into place by hand prior to crank mounting—once the crank bolts are torqued, the cover remains stable and secure.