The Shimano Dura Ace bottom bracket is known for its reliability. The bearings are designed to last a long time and run smoothly.

The bottom bracket is compatible with Shimano Hollowtech II road cranksets. There are three types: BSA, ITA, and Press Fit. This refers to the threading type. Most bikes use Press Fit, which is threadless.

BSA is 68mm, and the bracket is marked 1.37 x 24.

ITA is 70mm, and the outside is marked 36 x 24.