---
title: "What is a bicycle Sealed Bearing Hub?"
tags: ["yuhub","bicycle","hub","bicycle parts"]
categories: ["news"]
image: "https://images.pexels.com/photos/13325112/pexels-photo-13325112.jpeg"
url: "/news/sealed-bearing-hub/"
date: 2025-09-25T14:08:35+08:00
description: "What is a bicycle Sealed Bearing Hub?"
draft: false
display: true
type: "post"
---
# What is a bicycle Sealed Bearing Hub?

A bicycle **sealed bearing hub** uses a pre-assembled, self-contained cartridge bearing unit to allow the wheel to rotate smoothly around its axle. The "sealed" design means the internal ball bearings and grease are protected from water, dirt, and debris by integrated rubber or polymer seals.

This design offers significant advantages in durability and maintenance compared to traditional **"cup-and-cone"** hubs, which use loose ball bearings. Sealed bearing hubs are a popular feature on mid-to-high-end bikes across all disciplines, including road, mountain, and BMX.

[Bicycle Sealed Bearing Hub: Ultimate Guide for Cyclists](https://www.yuhub.com.tw/en/news/?method=detail&aid=42)

### How a sealed bearing hub works

* **Sealed cartridge:** The hub contains one or more cartridge bearing units that are pressed into place. Each cartridge is a self-contained unit with ball bearings, an inner race, an outer race, and integrated seals.
* **Press-fit installation:** The cartridges are installed into the hub shell and are not designed for regular disassembly.
* **Seals:** The rubber or polymer seals make light contact with the inner bearing race, creating a barrier that keeps the pre-filled grease inside and contaminants out.

### Sealed bearings vs. cup-and-cone bearings

| Feature | Sealed Bearings (Cartridge) | Cup-and-Cone Bearings (Loose Ball) |
| :--- | :--- | :--- |
| **Maintenance** | Low maintenance; the sealed unit is a "fit-and-forget" component. | High maintenance; requires regular disassembly, cleaning, and re-greasing to prevent premature wear. |
| **Protection** | Excellent protection against dirt and water due to integrated seals. | More vulnerable to contamination; requires careful adjustment and maintenance to keep dirt out. |
| **Serviceability**| Not designed to be serviced. When a cartridge wears out, the entire unit is replaced. | Fully serviceable. Components can be individually cleaned and replaced, including the balls and grease. |
| **Durability** | Generally very durable, though prone to catastrophic failure once the seals are compromised. | Extremely durable when well-maintained. Failure is gradual and may allow for repair before full replacement is needed. |
| **Adjustment** | No adjustment is needed or possible; the bearings are pre-adjusted at the factory. | Can be finely adjusted by tightening or loosening the cones, which can be finicky for some riders. |
| **Best for** | Riders who want minimal upkeep and maximum reliability, especially in wet or muddy conditions. | Riders who enjoy hands-on maintenance and seeking ultimate longevity with proper care. |