ENDURO BKCJ-0501 12/14T XD15 CERAMIC BEARING PULLEYS SRAM EAGLE 12SP - BLACK

The ultimate upgrade pulley. Guaranteed to last forever against corrosion

Crafted from precision-machined Delrin®, these derailleur pulleys incorporate XD-15 Ceramic-Hybrid radial bearings, delivering improved shifting precision and durability. Engineered for optimal performance, the upper pulley utilizes CN (tight clearance) bearings to enhance shifting accuracy, while the lower pulley features C4 (loose clearance) bearings to accommodate chain-line flexibility.

Made from 500 AF Delrin® infused with Teflon®, these pulleys combine exceptional mechanical tensile strength and rigidity with natural lubricity. Their high resistance to moisture, caustic chemicals, and UV exposure ensures long-lasting durability and smooth operation. Delrin’s precision machinability allows for clean, accurate manufacturing, while its inherent lubricative properties significantly reduce friction against the bicycle chain. Compared to aluminum or titanium alternatives, these pulleys deliver markedly lower drag for enhanced performance.

Exclusively from Enduro Bearings, the XD-15 Ceramic-Hybrid bearings feature corrosion-resistant, cryogenically treated nitrogen steel races combined with Grade 3 Silicon Nitride ceramic balls through an advanced proprietary process, delivering superior performance. Their deep-groove raceways accommodate larger ceramic balls, increasing contact area for enhanced durability and efficiency. Filled with 90% Kluber NBU52 grease, these bearings run smoother over time and resist washout, as the grease adheres to and continuously recirculates within the ball path. This 12-tooth upper and 14-tooth lower pulley set with 5mm bolt holes is designed as a performance upgrade for SRAM 12-speed cable-actuated Eagle derailleurs and includes the XD-15 cable idler pulley.

Enduro Derailleur Pulleys come in multiple configurations and performance tiers, ranging from Ceramic-Hybrid to the enhanced Black-Oxide treated Zero Ceramic, with the XD-15 Ceramic-Hybrid representing the premium option. Each pulley is precisely engineered and manufactured in the USA.