Enduro BKCJ-0457 11T Zero Ceramic Bearing Pulleys Shimano 11-Speed - Black

Experience the pinnacle of derailleur pulley technology with these precision-machined Delrin pulleys, equipped with XD15 Ceramic-Hybrid radial bearings to improve shifting accuracy and durability. Designed to resist corrosion indefinitely, the enhanced Directline model includes larger caps to reduce bearing play and prevent contamination, ensuring long-term reliable performance on your Shimano 11-speed drivetrain.

These Directline pulleys incorporate CN (tight clearance) bearings in the upper pulley to enhance shifting precision, while the lower pulley uses C4 (loose clearance) bearings to accommodate chain-line movement. Constructed from 500 AF Delrin, this material provides exceptional tensile strength, rigidity, and natural lubricity, along with excellent resistance to moisture, harsh chemicals, and UV exposure—making the pulleys durable, stiff, and exceptionally smooth. Delrin’s precise machinability ensures clean components, and its Teflon-infused composition significantly lowers friction against the chain, resulting in notably less drag compared to aluminum or titanium pulleys.

Exclusive to Enduro Bearings, the XD15 Ceramic-Hybrid bearings feature corrosion-resistant, cryogenically treated nitrogen steel races combined with Grade 5 Silicon Nitride ceramic balls through a proprietary process, delivering a premium high-performance bearing system. The deep-groove raceways accommodate oversized Grade 5 ceramic balls for greater contact area, enhancing durability and efficiency. Lubricated with 90% fill Kluber NBU 52 grease, these bearings improve with use and resist washout by adhering to the balls and continuously returning to the contact surfaces. Designed with eleven-tooth upper and thirteen-tooth lower pulleys and 5mm bolt-holes, they provide a direct upgrade for most 11- and 12-speed Shimano GRX 2X rear derailleurs, including models RD RX-810, RD RX-815, RD RX-820, and RD RX-825. (For 12-speed GRX RD RX-822 SG and SGS 1X derailleurs, use BKCJ-0361.)

Enduro Derailleur Pulleys come in multiple configurations and bearing grades, including Ceramic-Hybrid, Black-Oxide treated Zero Ceramic as an enhanced option, and the premium XD15 Ceramic-Hybrid. Each pulley is precision engineered and proudly manufactured in the USA to ensure top-tier quality and performance.