Shimano Dura Ace

Smooth Operator.

The Dura Ace BB is compatible with all Shimano Hollowtech II cranksets. By utilizing smaller, high-precision bearings and a refined seal structure, Shimano has reduced weight and rotational friction while simultaneously improving weather resistance. It is the "set-it-and-forget-it" component that ensures every watt you put into the pedals is transferred directly to the rear wheel.

Why It's the Pro-Tour Standard:

• Reduced Rotational Friction: Features high-grade stainless steel bearings that are smaller than previous generations. This reduces drag and saves valuable energy on long, high-speed rides.

• Advanced Seal Technology: The redesigned seals are tighter and more effective at keeping out water, mud, and road salt, ensuring your bearings stay smooth even in the worst conditions.

• Lightweight Design: Weighing in at approximately 65g, it is one of the lightest threaded bottom brackets on the market, helping you shave grams from your high-end build.

• Proven Hollowtech II Interface: Engineered specifically for 24mm spindles, providing a wider bearing stance for increased rigidity and power transfer compared to traditional square-taper systems.

• Quiet & Durable: The high-precision manufacturing and high-quality materials virtually eliminate the "creaks" often associated with lower-quality systems.

Technical Specifications:

• Series: DURA-ACE R9100

• Shell Width: 68mm

• Bearing Type: Stainless Steel (Small Ball)

• Interface: Hollowtech II (24mm Spindle)

• Weight: ~65g

The Alegro Perspective: In the shop, we call this the "the gold standard of bottom brackets." While many riders look for expensive ceramic upgrades, the steel bearings in the Dura Ace BB are so well-made that they often outperform ceramic options in terms of real-world longevity and consistency. It is the most reliable, best-performing part for the money in the entire Shimano catalog.

Minimal Friction. Maximum Durability. Support your Power with Shimano Dura-Ace.