Bike bottom brackets are a crucial component that connects the crankset to the frame of the bike. There are MANY different types of bottom brackets, each with its own set of advantages and disadvantages. In Singapore, the most common type of bottom bracket you'll find is the threaded bottom bracket.

In this article, we'll take a closer look at the four most common types of bike bottom brackets: Threaded, Octalink, Hollowtech II, and T47. We'll also explore how to identify the threading of your square taper bottom bracket, so you'll know what tools you'll need and exactly what you're dealing with.

1. Square Taper

Image credit: Bike Radar

The threaded square taper bottom bracket is the most traditional type of bottom bracket, and has been tried and tested for many years. It typically consists of a square spindle that fits into a square hole in the bike frame, and the cranks attach to the spindle via a taper, hence the name. Each side of the bottom bracket has shells that are threaded into the frame.

Square taper bottom brackets are known for their simplicity and reliability, and are commonly found on older bikes and entry-level models as they are cheap and easy to replace. They are also relatively easy to maintain compared to the other standards in this list, as the bearings can be easily replaced.

Here's where this style of bottom bracket can become a little confusing: they come in two different threading standards: English and Italian. The threading determines the direction in which the bottom bracket cup is threaded into the frame.

To identify the threading of your square taper bottom bracket, you'll need to remove the cranks and take a look at the threads on the bottom bracket cup. If the threads are right-handed (turn clockwise to tighten), it's an English thread. If the threads are left-handed (turn counterclockwise to tighten), it's an Italian thread. It's that simple! Our Frigate belt-driven bicycle uses an English threaded bottom bracket for its simplicity and reliability.

2. Octalink Bottom Bracket (Threaded)

Image Credit: Custom Junkies

The Octalink bottom bracket is a newer type of BB that uses a splined interface to connect the spindle to the cranks. Octalink bottom brackets are known for their stiffness and durability, and are commonly used on mountain bikes. Their hardiness and stiffness are great for transfering power from your legs down your drivetrain.

The key benefits of Octalink bottom brackets is that they are less likely to suffer from creaking or other noises than square taper bottom brackets. This is especially important if you're making big jumps and drops such as when you're out on the trails. They are also easier to install and remove, as the splined interface provides a more secure connection.

These bottom brackets also come in English or Italian threaded versions.

3. Hollowtech II Bottom Bracket (AKA Press Fit)

Image credit: Ebay

The Hollowtech II bottom bracket is a type of BB that uses a press-fit system to connect the spindle to the bike frame. The spindle and bearings are encased inside the bottom bracket shell.

Press fit bottom brackets are lightweight and offer improved stiffness compared to other types of bottom brackets. Like the Octalink, they are also less prone to creaking and other noises, and are generally easier to install and remove than square taper or Octalink bottom brackets.

However, Hollowtech II bottom brackets can be more difficult to service, making them a home mechanic's nightmare. This is because the press-fit design makes it more challenging to access the bearings, making them harder to service. They are also more expensive than other types of bottom brackets, and they are only compatible with specific frame designs and materials. So good luck finding a replacement unit that fits your frame exactly!

There is no thread for press-fit bottom brackets

4. T47 Bottom Bracket

Image credit: Wheels MFG

The T47 bottom bracket is a new type of bottom bracket that uses a larger diameter (47mm), hence the name, spindle and a threaded interface to connect the spindle to the frame. T47 bottom brackets are designed to be more compatible with a wider range of frame materials and designs. T47 bottom brackets are great for easier maintenance and replacement of the bearings, as the threaded interface (like the square taper) makes it easier to access the spindle. However, T47 bottom brackets are relatively new and are more expensive compared to other types of bottom brackets.

As with the square taper, this is also is threaded and have English and Italian threaded versions.


It's not difficult to identify the type of bottom bracket you have with a little research and careful observation of your bicycle. The easiest way would be to compare the photos on this page to those on your bike. As always, if you need help identifying your bottom bracket standard, feel free to contact us. Happy riding!

January 30, 2023 — Victor Tong


bob said:

Readers beware, this article is incorrect.

Alex said:

Your article states, “if the threads are right-handed (turn clockwise to tighten), it’s an English thread. If the threads are left-handed (turn counterclockwise to tighten), it’s an Italian thread.”

This is incorrect.

Aside from the different pitch and diameter, a RH English BB cup turns counter clockwise to tighten and it’s the other way round on the LH side – clockwise to tighten.

An Italian BB turns clockwise to tighten on both sides.

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