Bottom Brackets and Bearings

❓1. What are the main types of bottom brackets?

There are two main families:

• Threaded (BSA, ITA): the bottom bracket is threaded into the frame. It is the most reliable, easy to maintain and silent.
• Press-fit (BB86, BB92, PF30, BB30, etc.): the cups are pressed into the frame. Lighter but sometimes a source of creaking if poorly installed.

❓ 2. How do I know which bottom bracket is compatible with my frame and crankset?

Three measurements are essential:

The frame standard (BSA, BB86, PF30…).

The bottom bracket width (68 / 70 / 73 mm, etc.).

The bottom bracket axle diameter (24 mm Shimano, 30 mm, DUB 28.99 mm…).👉 The bottom bracket must match both to the frame and to the crankset axle.

❓ 3. What criteria should you prioritise when choosing a quality bottom bracket?

• Bearings: choose sealed and durable bearings (premium steel or ceramic depending on budget).
• Sealing: essential if you ride in the rain or on gravel/MTB.
• Stiffness: influences power transfer.
• Ease of maintenance: some models allow you to replace only the bearings.

Want to know more? Check out our advice guide:

How to choose your MTB bottom bracket