The BB90 - Bearing Kit - XD15 Pro - 24mm is a top-of-the-line bottom bracket bearing kit by Enduro Bearings. Specifically designed for Shimano 24mm cranksets and Trek BB90/95 framesets, this kit includes XD-15 Ceramic-Hybrid, ABEC-5 bearings along with all necessary seals and spacers for a precise and professional installation. Enduro Bearings' XD-15 Ceramic-Hybrid bearings are a proprietary creation, combining corrosion-proof, cryogenically treated nitrogen steel races with Grade 3 Silicon Nitride ceramic balls. This unique process results in the ultimate high-performance bearing setup. The deep-groove design raceways allow for maximum-sized ceramic balls, increasing contact area and improving performance and longevity. The XD-15 bearings come pre-packed with Kluber NBU52 grease, which provides superior long-term lubrication. Unlike other bearings, the XD-15 bearings actually improve with use, as the balls make the races even smoother over time. Enduro Bearings is so confident in the quality of their bearings that they offer an unlimited lifetime warranty on both the bearings and the races. For easy removal and installation, they recommend using the BRT-003 24mm x 37mm bearing tool. The Enduro line of bearings is available in various materials such as High-Carbon Chromium Steel, 440C Stainless Steel, Ceramic-Hybrid, and XD-15 with Ceramic or Stainless Balls. All bearings are engineered with deep groove races and feature dual-lip seals for ultimate protection against the elements. Category: Bottom Bracket Bearing Kit - XD15 Pro - 24mm Brand: Enduro Bearings Reference Number: BKC-54109 Warranty: Unlimited Lifetime