Shimano Ultegra bottom bracket unit with Italian Threads. Compatible with frames with a 70mm wide threaded BB Shell, and Shimano 24mm spindle chainsets, including Shimano 4700, 5800, and 6800 groupsets.
- HollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency
- HollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durability
- Use TLFC37 or TLFC25 in conjunction with TLFC36 adaptor tool for installation and removal
- Compatible with 70mm Italian Threaded frames.