- 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
- For use with Ultegra - 105 - CX70 chainwheels
