The Shimano HollowTech II bottom bracket is a direct replacement designed for 68mm English (BSA) threaded road bottom brackets, ensuring smooth, durable performance with fully serviceable components. This bottom bracket features Enduro ABEC-3 bearings, known for their precision and durability, with Grade 10 Chromium Steel Balls that offer twice the roundness of industry standards, ensuring high precision and smooth operation. The bearings are housed within 52100 high carbon chromium alloy races, hardened for toughness and polished to a mirror finish for noise-free, high-precision movement. The external bottom bracket is designed for 24mm crank spindles, compatible with Shimano HollowTech II, FSA, RaceFace EXI, X-Type, MegaExo, and Rotor 3D cranksets. Its Enduro silicone dust seals protect the bearings, enhancing durability even in tough riding conditions.

In addition to the high-quality bearings, the Shimano HollowTech II bottom bracket includes various spacers to ensure compatibility with a range of setups. These include two 2.5mm aluminum BB cup spacers, 0.5mm crank spindle spacers, and 1.0mm crank spindle spacers, providing precise adjustments for different cranksets. The bottom bracket shell width is 68mm, with a shell internal diameter of 33.6-33.9mm, making it a versatile option for many road bike frames. Weighing just 98g, this bottom bracket offers a lightweight yet durable solution for road cyclists, delivering high performance and easy maintenance. Enduro's bearings and silicone seals contribute to its long-lasting performance, making this bottom bracket an excellent choice for riders seeking reliability and smooth operation over time.