Enduro Bearings Derailleur pulleys Directline XD-15 Shimano Dura Ace 12 Speed

BKCJ-0452 - Machined derailleur pulleys made from Delrin, 11 teeth, XD-15 hybrid ceramic bearings for Shimano Dura Ace 12-speed derailleurs - (5 mm bolt hole) - The ultimate upgrade pulley. Guaranteed to last forever against corrosion. Precision machined Delrin derailleur pulleys, featuring XD-15 hybrid ceramic radial bearings for improved shifting performance and enhanced longevity. Designed and crafted for performance, these pulleys have CN bearings (tight clearance) in the upper pulley to maximise shifting accuracy and C4 bearings (loose clearance) in the lower pulley to allow chain line movement. The Delrin 500 AF pulley material offers high mechanical strength and rigidity, natural lubrication, strong resistance to moisture, caustic chemicals, and UV rays, making these pulleys very durable, stiff, and smooth. Delrin also machines very cleanly and precisely. The inherent lubricating qualities of this Teflon-infused material significantly reduce friction when in contact with the bike chain. Compared to other pulley materials, Delrin 500 AF with Teflon offers considerably lower friction compared to machined aluminium or titanium pulleys. An Enduro Bearings exclusive, our XD-15 hybrid ceramic bearings combine cryogenically treated corrosion-resistant nitrided steel races with Grade 5 silicon nitride ceramic balls in a proprietary process that leads to the ultimate high-performance bearing configuration. The deep groove raceway design accommodates larger Grade 5 silicon nitride ceramic balls for increased contact area and improved performance and longevity. The Kluber NBU52 grease filling 90% works better and smoother over time and is highly resistant to washing out. It is designed to cling to the balls and be continually drawn back into the ball path where it is needed. The eleven-tooth upper and lower pulleys with 5 mm bolt holes are designed as a direct upgrade for Shimano Dura Ace 12-speed derailleurs. Enduro derailleur pulleys are available in several configurations and performance levels, starting from hybrid ceramic, black oxide treated zero ceramic as an intermediate step, and XD-15 hybrid ceramic at the top of the range. All are proudly precision-made in the USA.